第 1 条，共 210 条
标题: Generation of single-cycle mid-infrared pulses via coherent synthesis 
作者: Ma, F (Ma, Fen); Liu, HJ (Liu, Hongjun); Huang, N (Huang, Nan); Sun, QB (Sun, Qibing)
来源出版物: OPTICS EXPRESS  卷: 20  期: 27  页: 28455-28464  DOI: 10.1364/OE.20.028455  出版年: DEC 17 2012  
Web of Science 核心合集中的 "被引频次": 1 
被引频次合计: 1 
摘要: A new approach for the generation of single-cycle mid-infrared pulses without complicated control systems is proposed, which is based on direct coherent synthesis of two idlers generated by difference frequency generation (DFG) processes. It is found that the waveform of synthesized pulses is mainly determined by the spectra superposition, the carrier-envelope phase (CEP) difference, the relative timing and the chirp ratio between the idlers. The influences of these parameters on the synthesized waveform are also numerically calculated and analyzed via second-order autocorrelation, which offers general guidelines for the waveform optimization. The single-cycle synthesized mid-infrared pulses, which are centered at 4233 nm with the spectrum spanning from 3000 nm to 7000 nm, are achieved by carefully optimizing these parameters. The single-cycle mid-infrared laser source presents the possibility of investigating and controlling the strong field light-matter interaction. (C) 2012 Optical Society of America
PubMed ID: 23263081 
文献类型: Article
KeyWords Plus: CARRIER-ENVELOPE PHASE; OPTICAL PARAMETRIC OSCILLATOR; CR-FORSTERITE LASERS; SELF-STABILIZATION; TI-SAPPHIRE; ENERGY; OFFSET
Web of Science 类别: Optics
研究方向: Optics
IDS 号: 089LG 
ISSN: 1094-4087 

第 2 条，共 210 条
标题: Unclassical ripple patterns in single-crystal silicon produced by femtosecond laser irradiation 
作者: Zhang, W (Zhang, Wei); Cheng, GG (Cheng, Guanghua); Feng, Q (Feng, Qiang)
来源出版物: APPLIED SURFACE SCIENCE  卷: 263  页: 436-439  DOI: 10.1016/j.apsusc.2012.09.075  出版年: DEC 15 2012  
Web of Science 核心合集中的 "被引频次": 5 
被引频次合计: 5 
摘要: Laser-induced periodic surface structures (LIPSS) in single-crystal silicon upon irradiation with multiple linearly polarized femtosecond (fs) laser pulses (120 fs, 800 nm, 1 kHz) were investigated under different laser fluence and pulse number. Unclassical ripples (U-ripples), which were nearly parallel to the polarization of the laser beam, were observed to form gradually on the top of classical ripples with the effective pulse number. Their periods were significantly longer than the laser wavelength, and increased with increasing both the laser fluence and pulse number in the current study. The relationship between the types of ripple patterns and their parametric dependence was established. The mechanism of U-ripple formation was attributed to the capillary wave, arising from the inhomogeneous temperature gradient combined with the electric field of the pulses in the molten surface layer. (C) 2012 Elsevier B. V. All rights reserved.
文献类型: Article
作者关键词: Femtosecond laser; LIPSS; Unclassical ripples; Capillary wave
KeyWords Plus: PULSES; SURFACE
Web of Science 类别: Chemistry, Physical; Materials Science, Coatings & Films; Physics, Applied; Physics, Condensed Matter
研究方向: Chemistry; Materials Science; Physics
IDS 号: 039BJ 
ISSN: 0169-4332 

第 3 条，共 210 条
标题: A new design of large area MCP-PMT for the next generation neutrino experiment 
作者: Wang, YF (Wang, Yifang); Qian, S (Qian, Sen); Zhao, T (Zhao, T.); Tian, JS (Tian, Jinshou); Li, HR (Li, Huirui); Cao, J (Cao, Jun); Xu, XY (Xu, Xiangyan); Wang, XY (Wang, Xiaoyun); Liu, SD (Liu, Shudong); Liu, HL (Liu, Hulin); Liu, SL (Liu, Shulin); Liu, DL (Liu, Delin); Heng, YK (Heng, Yuekun); Cao, XB (Cao, Xibin); Jun, ST (Jun Shentu)
来源出版物: NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT  卷: 695  页: 113-117  DOI: 10.1016/j.nima.2011.12.085  出版年: DEC 11 2012  
Web of Science 核心合集中的 "被引频次": 0 
被引频次合计: 1 
摘要: This manuscript discusses a new design of large area MCP-PMT for the next generation neutrino experiments. The main motivation of the design is to improve the quantum efficiency (photo detection efficiency) of the PMT. Two sets of small MCP units, the transmission photocathode coated on the front hemisphere and the reflection photocathode coated on the rear hemisphere are assembled in the same glass envelope to form nearly 4 pi viewing angle to enhance the efficiency of the photoelectron detection. The photoelectrons from the 4 pi photocathode are collected and amplified by two sets of MCP units. Our goal is eventually to produce 20 in. diameter PMT following such an approach. We will report preliminary results of our ptoelectronic simulation and the results of a 5 in. diameter prototype PMT. Future plans and prospects are discussed at the end. (C) 2011 Elsevier B.V. All rights reserved.
文献类型: Article
作者关键词: MCP; PMT; Large area photocathode; Neutrino experiment
Web of Science 类别: Instruments & Instrumentation; Nuclear Science & Technology; Physics, Particles & Fields; Spectroscopy
研究方向: Instruments & Instrumentation; Nuclear Science & Technology; Physics; Spectroscopy
IDS 号: 042KK 
ISSN: 0168-9002 

第 4 条，共 210 条
标题: High-peak-power, single-mode, nanosecond pulsed, all-fiber laser for high resolution 3D imaging LIDAR system 
作者: Yun, J (Yun, Jian); Gao, CX (Gao, Cunxiao); Zhu, SL (Zhu, Shaolan); Sun, CD (Sun, Chuandong); He, HD (He, Haodong); Feng, L (Feng, Li); Dong, LJ (Dong, Lijun); Niu, LQ (Niu, Linquan)
来源出版物: CHINESE OPTICS LETTERS  卷: 10  期: 12  文献号: 121402  DOI: 10.3788/COL201210.121402  出版年: DEC 10 2012  
Web of Science 核心合集中的 "被引频次": 6 
被引频次合计: 6 
摘要: This study presents an eye-safe, single-mode, nanosecond-pulsed, and all-fiber laser source with master-oscillator-power-amplifier configuration at 1 550 nm that is suitable for high-resolution three-dimensional (3D) imaging light detection and ranging (LIDAR) system. The output peak power of 7.6 kW is obtained at the 1.2-ns pulse width and 50-kHz repetition rate. The single-mode pulse laser output ensures the range precision and imaging results of the LIDAR system. The laser is used as a transmitter for the 3D imaging LIDAR system. The detailed characteristics of the LIDAR system and the results of the 3D imaging are presented.
文献类型: Article
KeyWords Plus: EYE-SAFE; ENERGY
Web of Science 类别: Optics
研究方向: Optics
IDS 号: 063SU 
ISSN: 1671-7694 

第 5 条，共 210 条
标题: Synthesis of two benzo[1,2-b:3,4-b ']dithiophene-based conjugated polymers with different side chains and their applications in photovoltaic devices 
作者: Qu, B (Qu, Bo); Yang, HS (Yang, Hongsheng); Tian, D (Tian, Di); Liu, HL (Liu, Hongli); Cong, ZY (Cong, Zhiyuan); Gao, C (Gao, Chao); Chen, ZJ (Chen, Zhijian); Xiao, LX (Xiao, Lixin); Gao, Z (Gao, Zhi); Wei, W (Wei, Wei); Gong, QH (Gong, Qihuang)
来源出版物: SYNTHETIC METALS  卷: 162  期: 23  页: 2020-2026  DOI: 10.1016/j.synthmet.2012.09.009  出版年: DEC 2012  
Web of Science 核心合集中的 "被引频次": 4 
被引频次合计: 4 
摘要: Two D-A conjugated polymers (named PBDTC6BT and PBDTC10DBT) with benzo[1,2-b:3,4-b']thiophene (BDT) as donor and 4,7-dithiophen-2,1,3-benzothiadiazole (DBT) as acceptor, were designed and synthesized. PBDTC6DBT and PBDTC10DBT have hexyl and decyl as side chains in the DBT units, respectively. The polymers were characterized by spectroscopic (NMR and UV-vis) methods, GPC, DSC and cyclic voltammetry. In order to study the photovoltaic properties of the two conjugated polymers, photovoltaic devices with the configuration of ITO/poly(3,4-ehylenedioxythiophene)-poly(styrenesulfonate) (PEDOT:PSS)/polymer:[6,6]-phenyl C-61-butyric acid methyl ester (PC61BM)/LiF/Al, were fabricated, in which PBDTC6DBT or PBDTC10DBT acted as electron donor in active layers. According to the experimental data, when the blend ratio of PBDTC6DBT and PC61 BM reached 1:2, the best photovoltaic properties among the PBDTC6DBT-based devices were obtained, and the open-circuit voltage, the short-circuit current density and the power conversion efficiency were measured to be 0.63 V, 6.18 mA/cm(2) and 1.86%, respectively. As to PBDTC10DBT-based devices, the maximum of power conversion efficiency reached 0.99% with the blend ratio of PBDTC10DBT and PC61BM being 1:2. PBDTC10DBT and PBDTC6DBT were both promising donor candidates in the application of polymer solar cells. (C) 2012 Elsevier B.V. All rights reserved,
文献类型: Article
作者关键词: Thiophene; Benzothiadiazole; Polymer; Organic photovoltaic device; Solar cell; Bulk-heterojunction
KeyWords Plus: HETEROJUNCTION SOLAR-CELLS; CONVERSION EFFICIENCY; POLYTHIOPHENES; PERFORMANCE; MORPHOLOGY; GRAPHENE
Web of Science 类别: Materials Science, Multidisciplinary; Physics, Condensed Matter; Polymer Science
研究方向: Materials Science; Physics; Polymer Science
IDS 号: 068YE 
ISSN: 0379-6779 

第 6 条，共 210 条
标题: Die Bonding of High Power 808 nm Laser Diodes With Nanosilver Paste 
作者: Yan, Y (Yan, Yi); Chen, X (Chen, Xu); Liu, XS (Liu, Xingsheng); Mei, YH (Mei, Yunhui); Lu, GQ (Lu, Guo-Quan)
来源出版物: JOURNAL OF ELECTRONIC PACKAGING  卷: 134  期: 4  文献号: 041003  DOI: 10.1115/1.4007271  出版年: DEC 2012  
Web of Science 核心合集中的 "被引频次": 2 
被引频次合计: 2 
摘要: Conduction-cooled high power laser diodes have a variety of significant commercial, industrial, and military applications. For these devices to perform effectively, an appropriate die-attached material meeting specific requirements must be selected. In this study, nanosilver paste, a novel die-attached material, was used in packaging the 60 W 808 nm high power laser diodes. The properties of the laser diodes operating in the continuous wave (CW) mode, including the characteristics of power-current-voltage (LIV), spectrum, near field, far field, near field linearity, spatial spectrum, and thermal impedance, were determined. In addition, destructive tests, including the die shear test, scanning acoustic microscopy, and the thermal rollover test, were conducted to evaluate the reliability of the die bonding of the 60 W 808 nm high power semiconductor laser with nanosilver paste. Thermal analyses of the laser diodes operating at CW mode with different die-attached materials, indium solder, gold-tin solder and nanosilver paste, were conducted by finite element analysis (FEA). According to the result of the FEA, the nanosilver paste resulted in the lowest temperature in the laser diodes. The test results showed that the nanosilver paste was a very promising die-attached material in packaging high power semiconductor laser. [DOI: 10.1115/1.4007271]
文献类型: Article
作者关键词: nanosilver paste; laser diodes; die bonding
KeyWords Plus: ATTACH MATERIALS; SILVER PASTE; ARRAYS
Web of Science 类别: Engineering, Electrical & Electronic; Engineering, Mechanical
研究方向: Engineering
IDS 号: 063VV 
ISSN: 1043-7398 

第 7 条，共 210 条
标题: Age-related changes in prostate zonal volumes as measured by high-resolution magnetic resonance imaging (MRI): a cross-sectional study in over 500 patients 
作者: Turkbey, B (Turkbey, Baris); Huang, R (Huang, Robert); Vourganti, S (Vourganti, Srinivas); Trivedi, H (Trivedi, Hari); Bernardo, M (Bernardo, Marcelino); Yan, P (Yan, Pingkun); Benjamin, C (Benjamin, Compton); Pinto, PA (Pinto, Peter A.); Choyke, PL (Choyke, Peter L.)
来源出版物: BJU INTERNATIONAL  卷: 110  期: 11  页: 1642-1647  DOI: 10.1111/j.1464-410X.2012.11469.x  出版年: DEC 2012  
Web of Science 核心合集中的 "被引频次": 4 
被引频次合计: 4 
摘要: OBJECTIVE
To use ability of magnetic resonance imaging (MRI) to investigate age-related changes in zonal prostate volumes.
PATIENTS AND METHODS
This Institutional Review Board approved, Health Insurance Portability and Accountability Act-compliant study consisted of 503 patients who underwent 3 T prostate MRI before any treatment for prostate cancer.
Whole prostate (WP) and central gland (CG) volumes were manually contoured on T2-weighted MRI using a semi-automated segmentation tool. WP, CG, peripheral zone (PZ) volumes were measured for each patient.
WP, CG, PZ volumes were correlated with age, serum prostate-specific antigen (PSA) level, International Prostate Symptom Score (IPSS), Sexual Health Inventory for Men (SHIM) scores.
RESULTS
Linear regression analysis showed positive correlations between WP, CG volumes and patient age (P < 0.001); there was no correlation between age and PZ volume (P= 0.173).
There was a positive correlation between WP, CG volumes and serum PSA level (P < 0.001), as well as between PZ volume and serum PSA level (P= 0.002).
At logistic regression analysis, IPSS positively correlated with WP, CG volumes (P < 0.001).
SHIM positively correlated with WP (P= 0.015) and CG (P= 0.023) volumes.
As expected, the IPSS of patients with prostate volumes (WP, CG) in first decile for age were significantly lower than those in tenth decile.
CONCLUSIONS
Prostate MRI is able to document age-related changes in prostate zonal volumes.
Changes in WP and CG volumes correlated inversely with changes in lower urinary tract symptoms.
These findings suggest a role for MRI in measuring accurate prostate zonal volumes; have interesting implications for study of age-related changes in the prostate.
PubMed ID: 22973825 
文献类型: Article
作者关键词: BPH; MRI; prostate zonal volumes; age-related changes
KeyWords Plus: URINARY FLOW-RATES; LONGITUDINAL CHANGES; NATURAL-HISTORY; HYPERPLASIA; ANTIGEN; MEN; ADENOCARCINOMA; POPULATION; SYMPTOMS; COHORT
Web of Science 类别: Urology & Nephrology
研究方向: Urology & Nephrology
IDS 号: 053BY 
ISSN: 1464-4096 

第 8 条，共 210 条
标题: Observations of three types of sidebands in a passively mode-locked soliton fiber laser 
作者: Han, DD (Han, D. D.); Yun, L (Yun, L.)
来源出版物: LASER PHYSICS  卷: 22  期: 12  页: 1837-1841  DOI: 10.1134/S1054660X12120092  出版年: DEC 2012  
Web of Science 核心合集中的 "被引频次": 0 
被引频次合计: 0 
摘要: We have experimentally observed three types of sidebands in a passively mode-locked soliton fiber laser with large anomalous dispersion for the first time to our best knowledge. By appropriately adjusting the polarization state of laser cavity, the conventional peak sidebands, peak-dip sidebands, and dip sidebands appear in the soliton spectra, respectively. The peak-dip and dip sidebands exhibit distinct characteristics from the conventional peak sidebands. The formation mechanism of the new type sidebands can be attributed to the periodic power variation. This work could help to a deeper insight of the spectrum shaping mechanism of conventional solitons.
文献类型: Article
KeyWords Plus: ERBIUM-DOPED FIBER; NET-NORMAL-DISPERSION; PHOTONIC CRYSTAL FIBER; DISSIPATIVE SOLITONS; RING LASER; PULSES; POLARIZATION; INSTABILITY; CAVITY; GENERATION
Web of Science 类别: Optics; Physics, Applied
研究方向: Optics; Physics
IDS 号: 050OO 
ISSN: 1054-660X 

第 9 条，共 210 条
标题: Multivariate Multilinear Regression 
作者: Su, Y (Su, Ya); Gao, XB (Gao, Xinbo); Li, XL (Li, Xuelong); Tao, DC (Tao, Dacheng)
来源出版物: IEEE TRANSACTIONS ON SYSTEMS MAN AND CYBERNETICS PART B-CYBERNETICS  卷: 42  期: 6  页: 1560-1573  DOI: 10.1109/TSMCB.2012.2195171  出版年: DEC 2012  
Web of Science 核心合集中的 "被引频次": 2 
被引频次合计: 2 
摘要: Conventional regression methods, such as multivariate linear regression (MLR) and its extension principal component regression (PCR), deal well with the situations that the data are of the form of low-dimensional vector. When the dimension grows higher, it leads to the under sample problem (USP): the dimensionality of the feature space is much higher than the number of training samples. However, little attention has been paid to such a problem. This paper first adopts an in-depth investigation to the USP in PCR, which answers three questions: 1) Why is USP produced? 2) What is the condition for USP, and 3) How is the influence of USP on regression. With the help of the above analysis, the principal components selection problem of PCR is presented. Subsequently, to address the problem of PCR, a multivariate multilinear regression (MMR) model is proposed which gives a substitutive solution to MLR, under the condition of multilinear objects. The basic idea of MMR is to transfer the multilinear structure of objects into the regression coefficients as a constraint. As a result, the regression problem is reduced to find two low-dimensional coefficients so that the principal components selection problem is avoided. Moreover, the sample size needed for solving MMR is greatly reduced so that USP is alleviated. As there is no closed-form solution for MMR, an alternative projection procedure is designed to obtain the regression matrices. For the sake of completeness, the analysis of computational cost and the proof of convergence are studied subsequently. Furthermore, MMR is applied to model the fitting procedure in the active appearance model (AAM). Experiments are conducted on both the carefully designed synthesizing data set and AAM fitting databases verified the theoretical analysis.
PubMed ID: 22677310 
文献类型: Article
作者关键词: Active appearance model (AAM); multivariate linear regression (MLR); principal component regression (PCR); under sample problem (USP)
KeyWords Plus: PRINCIPAL COMPONENT REGRESSION; DISCRIMINANT-ANALYSIS; GAIT RECOGNITION; TENSOR ANALYSIS; APPEARANCE; REPRESENTATION; TRACKING; MODELS; SELECTION; OBJECTS
Web of Science 类别: Automation & Control Systems; Computer Science, Artificial Intelligence; Computer Science, Cybernetics
研究方向: Automation & Control Systems; Computer Science
IDS 号: 040VS 
ISSN: 1083-4419 

第 10 条，共 210 条
标题: Dispersion-free quantum clock synchronization via fiber link 
作者: Hou, FY (Hou, Fei-yan); Dong, RF (Dong, Rui-fang); Quan, RA (Quan, Run-ai); Zhang, Y (Zhang, Yu); Bai, Y (Bai, Yun); Liu, T (Liu, Tao); Zhang, SG (Zhang, Shou-gang); Zhang, TY (Zhang, Tong-yi)
来源出版物: ADVANCES IN SPACE RESEARCH  卷: 50  期: 11  页: 1489-1494  DOI: 10.1016/j.asr.2012.07.029  出版年: DEC 1 2012  
Web of Science 核心合集中的 "被引频次": 0 
被引频次合计: 1 
摘要: We proposed a fiber-based quantum clock synchronization protocol by employing the dispersion cancellation feature of the frequency anti-correlated entangled source under the quantum interference measurement. It is shown that, the accuracy of the synchronization is mainly dependent on the bandwidth of the frequency entangled biphoton spectrum and on the temperature variation induced fluctuations in both the reference fiber coiling and the fiber link. With this proposal, synchronization between two clocks at a distance of ten kilometers can be implemented with an accuracy below a picosecond. (C) 2012 COSPAR. Published by Elsevier Ltd. All rights reserved.
文献类型: Article
作者关键词: Frequency anti-correlated entanglement; Dispersion-free; Quantum clock synchronization via fiber link
KeyWords Plus: TIME TRANSFER; CANCELLATION; FREQUENCY
Web of Science 类别: Astronomy & Astrophysics; Geosciences, Multidisciplinary; Meteorology & Atmospheric Sciences
研究方向: Astronomy & Astrophysics; Geology; Meteorology & Atmospheric Sciences
IDS 号: 027YI 
ISSN: 0273-1177 

第 11 条，共 210 条
标题: Sideband-controllable mode-locking fiber laser based on chirped fiber Bragg gratings 
作者: Han, DD (Han, Dongdong); Liu, XM (Liu, Xueming)
来源出版物: OPTICS EXPRESS  卷: 20  期: 24  页: 27045-27050  DOI: 10.1364/OE.20.027045  出版年: NOV 19 2012  
Web of Science 核心合集中的 "被引频次": 11 
被引频次合计: 11 
摘要: We have proposed a sideband-controllable fiber soliton laser by means of chirped fiber Bragg gratings (CFBGs). Each side of the spectral sidebands of laser could be removed by using a CFBG with proper dispersion. Numerical simulations have well reproduced the experimental observations. The numerical and experimental investigations show that the generation of the unilateral sidebands is attributed to the CFBG-induced spectral filtering effect. Our work provides an effective way to manage conventional solitons with spectral sidebands. (C) 2012 Optical Society of America
PubMed ID: 23187560 
文献类型: Article
KeyWords Plus: NET-NORMAL-DISPERSION; DISSIPATIVE SOLITONS; LOCKED LASERS; GENERATION
Web of Science 类别: Optics
研究方向: Optics
IDS 号: 055YB 
ISSN: 1094-4087 

第 12 条，共 210 条
标题: Virtual source for an Airy beam 
作者: Yan, SH (Yan, Shaohui); Yao, BL (Yao, Baoli); Lei, M (Lei, Ming); Dan, D (Dan, Dan); Yang, YL (Yang, Yanlong); Gao, P (Gao, Peng)
来源出版物: OPTICS LETTERS  卷: 37  期: 22  页: 4774-4776  出版年: NOV 15 2012  
Web of Science 核心合集中的 "被引频次": 3 
被引频次合计: 4 
摘要: We identify a virtual source for generating an Airy wave. A spectral integral expression is derived to describe the Airy wave, which, in the paraxial limit, yields the freely accelerating, nondiffracting, and finite energy Airy beam. From the spectral representation of the Airy wave, the first two orders of nonparaxial corrections to the paraxial Airy beam are determined. Also, a connection between the obtained Airy wave and the well-known complex source point spherical wave is given. (C) 2012 Optical Society of America
PubMed ID: 23164909 
文献类型: Article
KeyWords Plus: GAUSSIAN-BEAM; EVANESCENT WAVES; FIELDS
Web of Science 类别: Optics
研究方向: Optics
IDS 号: 038JA 
ISSN: 0146-9592 

第 13 条，共 210 条
标题: Portable fiber group velocity test method with a gain-switched laser 
作者: Feng, Y (Feng, Ye); Zou, L (Zou, Lin); Wang, YS (Wang, Yi Shan); Zhao, W (Zhao, Wei); Yang, Z (Yang, Zhi); Zhang, W (Zhang, Wei); Hu, XH (Hu, Xiao Hong)
来源出版物: APPLIED OPTICS  卷: 51  期: 32  页: 7745-7749  DOI: 10.1364/AO.51.007745  出版年: NOV 10 2012  
Web of Science 核心合集中的 "被引频次": 0 
被引频次合计: 0 
摘要: A portable method of group velocity measurement is proposed based on a self-seeded gain-switched laser. The calculated group velocity in the optical fiber is obtained by measuring the round-trip frequencies of the gain-switched laser diode with different external cavities, and only a 2 m long fiber is needed. The measurement can be accomplished without oscilloscope or optical spectrum analyzer. The error associated with this test is within 0.65%, which is limited by the jitter of the voltage-controlled oscillator. Its spectrum resolution is 0.1 nm. (C) 2012 Optical Society of America
PubMed ID: 23142884 
文献类型: Article
KeyWords Plus: PULSES; DIODE; INTERFEROMETRY
Web of Science 类别: Optics
研究方向: Optics
IDS 号: 037EF 
ISSN: 1559-128X 
电子 ISSN: 2155-3165 

第 14 条，共 210 条
标题: Three-dimensional reconstruction of laser-imploded targets from simulated pinhole images 
作者: Xu, P (Xu, Peng); Bai, YL (Bai, Yonglin); Bai, XH (Bai, Xiaohong); Liu, BY (Liu, Baiyu); Ouyang, X (Ouyang, Xian); Wang, B (Wang, Bo); Yang, WZ (Yang, Wenzheng); Gou, YS (Gou, Yongsheng); Zhu, BL (Zhu, Bingli); Qin, JJ (Qin, Junjun)
来源出版物: APPLIED OPTICS  卷: 51  期: 32  页: 7820-7825  DOI: 10.1364/AO.51.007820  出版年: NOV 10 2012  
Web of Science 核心合集中的 "被引频次": 2 
被引频次合计: 2 
摘要: This paper proposes an integral method to achieve a more accurate weighting matrix that makes very positive contributions to the image reconstruction in inertial confinement fusion research. Standard algebraic reconstruction techniques with a positivity constraint included are utilized. The final normalized mean-square error between the simulated and reconstructed projection images is 0.000365%, which is a nearly perfect result, indicating that the weighting matrix is very important. Compared with the error between the simulated and reconstructed phantoms, which is 2.35%, it seems that the improvement of the accuracy of the projection image does not mean the improvement of the phantom. The proposed method can reconstruct a simulated laser-imploded target consisting of 100 x 100 x 100 voxels. (C) 2012 Optical Society of America
PubMed ID: 23142895 
文献类型: Article
KeyWords Plus: RAY; PROJECTIONS; ALGORITHM
Web of Science 类别: Optics
研究方向: Optics
IDS 号: 037EF 
ISSN: 1559-128X 
电子 ISSN: 2155-3165 

第 15 条，共 210 条
标题: Tunable high-channel-count bandpass plasmonic filters based on an analogue of electromagnetically induced transparency 
作者: Lu, H (Lu, Hua); Liu, XM (Liu, Xueming); Wang, GX (Wang, Guoxi); Mao, D (Mao, Dong)
来源出版物: NANOTECHNOLOGY  卷: 23  期: 44  文献号: 444003  DOI: 10.1088/0957-4484/23/44/444003  出版年: NOV 9 2012  
Web of Science 核心合集中的 "被引频次": 22 
被引频次合计: 22 
摘要: We have proposed a novel type of bandpass plasmonic filter consisting of metal-insulator-metal bus waveguides coupled with a series of side-coupled cavities and stub waveguides. The theoretical modeling demonstrates that our waveguide-resonator system performs a plasmonic analogue of electromagnetically induced transparency (EIT) in atomic systems, as is confirmed by numerical experiments. The plasmonic EIT-like response enables the realization of nanoscale bandpass filters with multiple channels. Additionally, the operating wavelengths and bandwidths of our filters can be efficiently tuned by adjusting the geometric parameters such as the lengths of stub waveguides and the coupling distances between the cavities and stub waveguides. The ultracompact configurations contribute to the achievement of wavelength division multiplexing systems for optical computing and communications in highly integrated optical circuits.
PubMed ID: 23079958 
文献类型: Article
KeyWords Plus: WAVE-GUIDE FILTERS; RESONATOR; LOCALIZATION; PROPAGATION; REFLECTION; POLARITONS; GRATINGS
Web of Science 类别: Nanoscience & Nanotechnology; Materials Science, Multidisciplinary; Physics, Applied
研究方向: Science & Technology - Other Topics; Materials Science; Physics
IDS 号: 030ML 
ISSN: 0957-4484 
电子 ISSN: 1361-6528 

第 16 条，共 210 条
标题: Numerical investigation of an all-optical switch in a graded nonlinear plasmonic grating 
作者: Wang, GX (Wang, Guoxi); Lu, H (Lu, Hua); Liu, XM (Liu, Xueming); Gong, YK (Gong, Yongkang)
来源出版物: NANOTECHNOLOGY  卷: 23  期: 44  文献号: 444009  DOI: 10.1088/0957-4484/23/44/444009  出版年: NOV 9 2012  
Web of Science 核心合集中的 "被引频次": 14 
被引频次合计: 14 
摘要: We have proposed and numerically investigated an all-optical switch based on a metal-insulator-metal waveguide with graded nonlinear plasmonic gratings. The influences of grating depth and refractive index of a Kerr nonlinear medium on the transmission of the switch are exactly analyzed by utilizing transmission line theory. The finite-difference time-domain simulation results show that the highly compact structure possesses excellent switch function by tuning the incident electric field intensity. In addition, the simulation results show that this all-optical switch has an ultrawide operating frequency regime and femtosecond-scale response time (similar to 130 fs). Such a switch can find potential applications for all-optical signal processing and optical communication.
PubMed ID: 23080383 
文献类型: Article
KeyWords Plus: WAVE-GUIDE; BRAGG GRATINGS; STUB STRUCTURE
Web of Science 类别: Nanoscience & Nanotechnology; Materials Science, Multidisciplinary; Physics, Applied
研究方向: Science & Technology - Other Topics; Materials Science; Physics
IDS 号: 030ML 
ISSN: 0957-4484 
电子 ISSN: 1361-6528 

第 17 条，共 210 条
标题: Can Fixed Time Delay Signature be Concealed in Chaotic Semiconductor Laser With Optical Feedback? 
作者: Wu, Y (Wu, Yuan); Wang, YC (Wang, Yun-Cai); Li, P (Li, Pu); Wang, AB (Wang, An-Bang); Zhang, MJ (Zhang, Ming-Jiang)
来源出版物: IEEE JOURNAL OF QUANTUM ELECTRONICS  卷: 48  期: 11  页: 1371-1379  DOI: 10.1109/JQE.2012.2212001  出版年: NOV 2012  
Web of Science 核心合集中的 "被引频次": 5 
被引频次合计: 5 
摘要: External-cavity lasers are usually used for chaos encryption in optical chaos-based communication systems. The external-cavity round-trip time (the time delay in the laser dynamics) is often regarded as an additional key to encode messages, which is a critical security parameter. The feasibility of identifying the time delay has been a crucial issue in chaotic optical communication. Some researchers propose that the time delay can be hidden by modulating the value of feedback strength or increasing the number of feedback cavities. In this paper, we experimentally and numerically demonstrate that the time delay signatures cannot be concealed in optical feedback semiconductor lasers. Whether single or double optical feedback, the time delay signatures can all be identified by the power spectrum analysis method. Furthermore, adjusting the feedback strength, the pumping current and the time-delay value, we find that the extraction of the time delay signatures still cannot be influenced.
文献类型: Article
作者关键词: Chaos; optical feedback; semiconductor laser; time delay
KeyWords Plus: SYNCHRONIZATION; SYSTEMS; DIODE; IDENTIFICATION; SUBJECT; SERIES; OUTPUT
Web of Science 类别: Engineering, Electrical & Electronic; Optics; Physics, Applied
研究方向: Engineering; Optics; Physics
IDS 号: 097DZ 
ISSN: 0018-9197 

第 18 条，共 210 条
标题: Switchable mode-locking fiber laser with fiber Bragg gratings 
作者: Han, DD (Han, Dongdong)
来源出版物: OPTICAL ENGINEERING  卷: 51  期: 11  文献号: 114202  DOI: 10.1117/1.OE.51.11.114202  出版年: NOV 2012  
Web of Science 核心合集中的 "被引频次": 0 
被引频次合计: 0 
摘要: A switchable mode-locking fiber laser is proposed by means of fiber Bragg grating (FBG). The FBG plays two key roles, the switchable wavelength operation and the spectral filtering effect, on the proposed laser. The switchable single-wavelength mode-locking operation, lasing at either 1545.25 or 1548.34 nm, corresponding to the central wavelengths of the FBGs, is obtained by appropriately rotating the polarization controllers (PC). In addition, the dual-wavelength mode-locking operation is observed with proper PC state. The switchable mode-locking operation attributes to the wavelength-dependent loss mechanism and the spectral filter formed by PCs and FBGs. (C) 2012 Society of Photo-Optical Instrumentation Engineers (SPIE). [DOI: 10.1117/1.OE.51.11.114202]
文献类型: Article
作者关键词: nonlinear polarization rotation; fiber Bragg grating; fiber laser
KeyWords Plus: ERBIUM-DOPED FIBER; PHOTONIC CRYSTAL FIBER; NET-NORMAL-DISPERSION; ANOMALOUS-DISPERSION; DISSIPATIVE SOLITONS; RING LASER; LOCKED LASERS; PULSES; POLARIZATION; GENERATION
Web of Science 类别: Optics
研究方向: Optics
IDS 号: 083KJ 
ISSN: 0091-3286 

第 19 条，共 210 条
标题: Experimental study on the imaging of the squeezed-state light with a virtual object 
作者: Lu, BZ (Lu, Baozhu); Bi, SW (Bi, Siwen); Feng, F (Feng, Fei); Kang, MH (Kang, Menghua); Qin, F (Qin, Fei)
来源出版物: OPTICAL ENGINEERING  卷: 51  期: 11  文献号: 119001  DOI: 10.1117/1.OE.51.11.119001  出版年: NOV 2012  
Web of Science 核心合集中的 "被引频次": 2 
被引频次合计: 2 
摘要: A stable amplitude squeezed-state light was generated by utilizing the nondegenerate optical parametric amplifier based on periodically poled KTiOPO4 crystal at 1064 nm. We observed -4.93 dB of squeezing with a local oscillator phase locked in homodyne measurement. The imaging experiments of the resolution target have shown that the imaging resolution, which was based on squeezed-state light, is 1.41 times as much as the resolution that was acquired using coherent light as light source. In addition, the squeezed-state light was applied for imaging of the virtual object. It was found that the characters on the board were much more easily discerned with squeezed light as a light source than with coherent light. This result paves the way for further improvements of imaging resolution by use of the squeezed-state light. (C) 2012 Society of Photo-Optical Instrumentation Engineers (SPIE). [DOI: 10.1117/1.OE.51.11.119001]
文献类型: Article
作者关键词: squeezed states; resolution; imaging system
KeyWords Plus: QUANTUM TELEPORTATION; PHASE; GENERATION
Web of Science 类别: Optics
研究方向: Optics
IDS 号: 083KJ 
ISSN: 0091-3286 

第 20 条，共 210 条
标题: Terahertz and mid-infrared spectroscopy of benzene-1,2-diol 
作者: Zheng, ZP (Zheng, Zhuan-Ping); Fan, WH (Fan, Wen-Hui); Yan, H (Yan, Hui); Liu, J (Liu, Jia); Yang, WZ (Yang, Wen-Zheng); Zhu, SL (Zhu, Shao-Lan)
来源出版物: JOURNAL OF MOLECULAR SPECTROSCOPY  卷: 281  页: 13-17  DOI: 10.1016/j.jms.2012.09.005  出版年: NOV 2012  
Web of Science 核心合集中的 "被引频次": 2 
被引频次合计: 2 
摘要: The terahertz (THz) and mid-infrared (MIR) spectra of benzene-1,2-diol in the solid state have been modeled by density functional theory (DFT). Calculations of the vibrational spectra based on the optimized geometries provided a good fit to the observed spectra, and a more reasonable spectral reproduction has been achieved than those in previous work. For THz spectrum, the simulation based on the varied unit cell dimension has clearly shown that THz spectral reproduction is affected by the temperature change of unit cell. For MIR spectrum, band assignments are reported in terms of potential-energy distribution (PED). which differ to those previously reported for benzene-1,2-diol in some respects. (c) 2012 Elsevier Inc. All rights reserved.
文献类型: Article
作者关键词: Terahertz; IR spectroscopy; Density functional theory; Benzene-12-diol
KeyWords Plus: FUNCTIONAL PERTURBATION-THEORY; TIME-DOMAIN SPECTROSCOPY; VIBRATIONAL-SPECTRA; CATECHOL; PYROCATECHOL; HYDROQUINONE; RESORCINOL; SOLIDS; CASTEP; MODES
Web of Science 类别: Physics, Atomic, Molecular & Chemical; Spectroscopy
研究方向: Physics; Spectroscopy
IDS 号: 046NH 
ISSN: 0022-2852 

第 21 条，共 210 条
标题: Modeling and testing of static pressure within an optical fiber cable spool using distributed fiber Bragg gratings 
作者: Ma, CJ (Ma, Chengju); Ren, LY (Ren, Liyong); Qu, ES (Qu, Enshi); Tang, F (Tang, Feng); Liang, Q (Liang, Quan)
来源出版物: OPTICS COMMUNICATIONS  卷: 285  期: 24  页: 4949-4953  DOI: 10.1016/j.optcom.2012.07.064  出版年: NOV 1 2012  
Web of Science 核心合集中的 "被引频次": 0 
被引频次合计: 0 
摘要: Based on the force analysis, we establish a theoretical model to study the static pressure distribution of the fiber cable spool for the fiber optic guided missile (FOG-M). Simulations indicate that for each fiber layer in the fiber cable spool, the applied static pressure on it asymptotically converges as the number of fiber layers increases. Using the distributed fiber Bragg grating (FBG) sensing technique, the static pressure of fiber cable layers in the spool on the cable winding device was measured. Experiments show that the Bragg wavelength of FBG in every layer varies very quickly at the beginning and then becomes gently as the subsequent fiber cable was twisted onto the spool layer by layer. Theoretical simulations agree qualitatively with experimental results. This technology provides us a real-time method to monitor the pressure within the fiber cable layer during the cable winding process. (C) 2012 Elsevier B.V. All rights reserved.
文献类型: Article
作者关键词: Fiber cable spool; Fiber optic guided missile (FOG-M); Fiber Bragg grating (FBG); Axial direction strain; Radial direction strain; Pressure
KeyWords Plus: SENSOR; SENSITIVITY
Web of Science 类别: Optics
研究方向: Optics
IDS 号: 038TH 
ISSN: 0030-4018 

第 22 条，共 210 条
标题: Theoretical study on instantaneous linewidth of Fourier-domain mode-locked fiber lasers 
作者: Tu, CH (Tu, Chenghou); Deng, YX (Deng, Yixin); Cai, MQ (Cai, Mengqiang); Huang, ZC (Huang, Zhangchao); Li, YN (Li, Yongnan); Lu, FY (Lu, Fuyun); Li, EB (Li, Enbang)
来源出版物: OPTICS COMMUNICATIONS  卷: 285  期: 24  页: 5287-5292  DOI: 10.1016/j.optcom.2012.06.072  出版年: NOV 1 2012  
Web of Science 核心合集中的 "被引频次": 0 
被引频次合计: 0 
摘要: We have numerically simulated the operation of the Fourier-domain mode-locked (FDML) fiber laser based on the wavelength reconstruction method instead of numerical solving the nonlinear Schrodinger equation. We studied the influences of the filter bandwidth and the relative time delay caused by the fiber chromatic dispersion on the instantaneous linewidth of the FDML fiber laser. The results show that the instantaneous linewidth broadens as the filter bandwidth and the relative time delay increase. When the filter has the bandwidth of 0.02 nm, the narrowest and broadest instantaneous linewidths are 0.024 and 0.042 nm, respectively. We give an understanding for the oscillation of the instantaneous linewidth of FDML. The presented result can be used to evaluate the performance achievable in the FDML fiber lasers. (C) 2012 Elsevier B.V. All rights reserved.
文献类型: Article
作者关键词: Fiber lasers; Fourier-domoain; Mode-locking; Instantaneous linewidth
KeyWords Plus: OPTICAL COHERENCE TOMOGRAPHY; MEGAHERTZ OCT; SWEPT LASERS
Web of Science 类别: Optics
研究方向: Optics
IDS 号: 038TH 
ISSN: 0030-4018 

第 23 条，共 210 条
标题: Theoretical analysis of output performance of GG-IAG fiber laser by multipoint distributed side pump 
作者: Zhu, YG (Zhu, Yonggang); Duan, KL (Duan, Kailiang); Shao, HM (Shao, Hongmin); Zhao, BY (Zhao, Baoyin); Zhang, ET (Zhang, Entao); Zhao, W (Zhao, Wei)
来源出版物: OPTICS COMMUNICATIONS  卷: 285  期: 24  页: 5359-5363  DOI: 10.1016/j.optcom.2012.08.019  出版年: NOV 1 2012  
Web of Science 核心合集中的 "被引频次": 2 
被引频次合计: 2 
摘要: Based on a steady-state rate equations (REs) and heat dissipation model considering both convective and radiative heat transfer, the output performance and temperature distribution of Yb3+ doped gain guided and index antiguided (GG-IAG) fiber lasers by multipoint distributed pumping are analyzed by numerically solving REs. The results show that high output power and even temperature distribution can be obtained by increasing pump points and lowering the losses at the points; multipoint side pumping is an optimal method to obtain compact high power GG-IAG fiber lasers. The numerical analysis provides some insights for the construction of high power GG-IAG fiber lasers. (C) 2012 Elsevier B.V. All rights reserved.
文献类型: Article
作者关键词: Gain guided; Index antiguided; Fiber lasers; Side pump
KeyWords Plus: INDEX-ANTIGUIDED FIBER; SINGLE-MODE; CORE
Web of Science 类别: Optics
研究方向: Optics
IDS 号: 038TH 
ISSN: 0030-4018 

第 24 条，共 210 条
标题: Evolution of dual-wavelength fiber laser from continuous wave to soliton pulses 
作者: Yun, L (Yun, Ling); Han, DD (Han, Dongdong)
来源出版物: OPTICS COMMUNICATIONS  卷: 285  期: 24  页: 5406-5409  DOI: 10.1016/j.optcom.2012.07.114  出版年: NOV 1 2012  
Web of Science 核心合集中的 "被引频次": 1 
被引频次合计: 1 
摘要: Evolution of dual-wavelength fiber laser from continuous wave to soliton pulses is investigated experimentally by using the nonlinear polarization rotation technique. With the increase of pump power, the proposed laser successively delivers the dual-wavelength continuous wave, the single-wavelength soliton pulses, and the dual-wavelength soliton pulses. The dual-wavelength laser operates at the central wavelengths of about 1533 and 1546 nm with the separation of similar to 13 nm. The number of soliton pulses operating in the dual-wavelength state is much larger than that of the single-wavelength state, while the pulse intensity always keeps constant. Experimental results reveal that the dual-wavelength mode locking is determined by the combination of pump strength and the cavity filtering effect. (C) 2012 Elsevier B.V. All rights reserved.
文献类型: Article
作者关键词: Fiber laser; Soliton; Mode-locking
KeyWords Plus: ERBIUM-DOPED FIBER; NONLINEAR POLARIZATION ROTATION; PHOTONIC CRYSTAL FIBER; NET-NORMAL-DISPERSION; RING LASER; DISSIPATIVE SOLITONS; BRAGG GRATINGS; GENERATION
Web of Science 类别: Optics
研究方向: Optics
IDS 号: 038TH 
ISSN: 0030-4018 

第 25 条，共 210 条
标题: Optical bistability based on an analog of electromagnetically induced transparency in plasmonic waveguide-coupled resonators 
作者: Cui, YD (Cui, Yudong); Zeng, C (Zeng, Chao)
来源出版物: APPLIED OPTICS  卷: 51  期: 31  页: 7482-7486  DOI: 10.1364/AO.51.007482  出版年: NOV 1 2012  
Web of Science 核心合集中的 "被引频次": 5 
被引频次合计: 5 
摘要: We have investigated numerically an optical bistability effect based on an analog of electromagnetically induced transparency (EIT) in a nanoscale plasmonic waveguide-coupled resonator system. The system consists of a metal-insulator-metal waveguide side-coupled with a slot cavity and a nanodisk cavity containing Kerr nonlinear material. By finite-difference time-domain simulations, the EIT-like spectral peak has a redshift with an increase of the dielectric constant of the nanodisk cavity. More importantly, we have achieved an optical bistability with threshold intensity about three times lower than that of recent literature [Appl. Opt. 50, 5287 (2011)]. The results show that our plasmonic structure can find more excellent application in highly integrated optical circuits, especially all-optical switching. (C) 2012 Optical Society of America
PubMed ID: 23128694 
文献类型: Article
KeyWords Plus: NANODISK RESONATORS; NANOCAVITIES; REFLECTION; ABSORPTION; GRATINGS; FILTERS; CHIP
Web of Science 类别: Optics
研究方向: Optics
IDS 号: 031LF 
ISSN: 1559-128X 
电子 ISSN: 2155-3165 

第 26 条，共 210 条
标题: Soliton mode locking fiber laser with an all-fiber polarization interference filter 
作者: Yan, ZJ (Yan, Zhijun); Wang, HS (Wang, Hushan); Zhou, KM (Zhou, Kaiming); Wang, YS (Wang, Yishan); Li, C (Li, Cheng); Zhao, W (Zhao, Wei); Zhang, L (Zhang, Lin)
来源出版物: OPTICS LETTERS  卷: 37  期: 21  页: 4522-4524  出版年: NOV 1 2012  
Web of Science 核心合集中的 "被引频次": 2 
被引频次合计: 2 
摘要: l An erbium doped fiber ring laser achieving soliton mode locking by the use of an intra-cavity all-fiber polarization interference filter (AFPIF) has been demonstrated. To incorporate an AFPIF with relative narrow transmission bandwidth, the laser has produced clean soliton pulses of 1.2 ps duration at a repetition rate of 14.98 MHz with a polarization extinction ratio up to 25.7 dB. Moreover, we have demonstrated that the operating wavelength of the mode locking laser can be tuned over 20 nm range from 1545 to 1565 nm by thermally tuning the AFPIF cavity. (C) 2012 Optical Society of America
PubMed ID: 23114350 
文献类型: Article
KeyWords Plus: GENERATION; PULSE
Web of Science 类别: Optics
研究方向: Optics
IDS 号: 030NP 
ISSN: 0146-9592 

第 27 条，共 210 条
标题: Creation of periodic subwavelength ripples on tungsten surface by ultra-short laser pulses 
作者: Xue, L (Xue, Lu); Yang, JJ (Yang, Jianjun); Yang, Y (Yang, Yang); Wang, YS (Wang, Yishan); Zhu, XN (Zhu, Xiaonong)
来源出版物: APPLIED PHYSICS A-MATERIALS SCIENCE & PROCESSING  卷: 109  期: 2  页: 357-365  DOI: 10.1007/s00339-012-7261-3  出版年: NOV 2012  
Web of Science 核心合集中的 "被引频次": 3 
被引频次合计: 3 
摘要: Formation of periodic subwavelength ripples on a metallic tungsten surface is investigated through a line-scribing method under the irradiation of 800 nm, 50 fs to 8 ps ultra-short laser pulses. The distinctive features of the induced ripple structures are described in detail with different laser parameters. Experimental measurements reveal that with gradual decrease of the laser fluence, the pulse duration or the scanning speed, the ripple period is inclined to reduce but the ripple depth tends to become pronounced. Theoretical analyses suggest that the transient dielectric function change of the tungsten surface mainly originates from the nonequilibrium distribution of electrons due to the d-band transitions. A sandwich-like physical model of air-plasma-target is proposed and the excitation of a surface plasmon polaritonic (SPP) wave is supposed to occur on the interface between the metallic target and the electron plasma layer. Formation of ripples can be eventually attributed to the laser-SPP interference. Theoretical interpretations are consistent with the experimental observations.
文献类型: Article
KeyWords Plus: ABLATION; ILLUMINATION; ELECTRON; FILM
Web of Science 类别: Materials Science, Multidisciplinary; Physics, Applied
研究方向: Materials Science; Physics
IDS 号: 026AR 
ISSN: 0947-8396 

第 28 条，共 210 条
标题: Single Image Super-Resolution With Non-Local Means and Steering Kernel Regression 
作者: Zhang, KB (Zhang, Kaibing); Gao, XB (Gao, Xinbo); Tao, DC (Tao, Dacheng); Li, XL (Li, Xuelong)
来源出版物: IEEE TRANSACTIONS ON IMAGE PROCESSING  卷: 21  期: 11  页: 4544-4556  DOI: 10.1109/TIP.2012.2208977  出版年: NOV 2012  
Web of Science 核心合集中的 "被引频次": 20 
被引频次合计: 21 
摘要: Image super-resolution (SR) reconstruction is essentially an ill-posed problem, so it is important to design an effective prior. For this purpose, we propose a novel image SR method by learning both non-local and local regularization priors from a given low-resolution image. The non-local prior takes advantage of the redundancy of similar patches in natural images, while the local prior assumes that a target pixel can be estimated by a weighted average of its neighbors. Based on the above considerations, we utilize the non-local means filter to learn a non-local prior and the steering kernel regression to learn a local prior. By assembling the two complementary regularization terms, we propose a maximum a posteriori probability framework for SR recovery. Thorough experimental results suggest that the proposed SR method can reconstruct higher quality results both quantitatively and perceptually.
PubMed ID: 22829403 
文献类型: Article
作者关键词: Image super-resolution; non-local means; regularization prior; self-similarity; steering kernel regression
KeyWords Plus: QUALITY ASSESSMENT; INTERPOLATION; RECONSTRUCTION; RESOLUTION; ALGORITHM
Web of Science 类别: Computer Science, Artificial Intelligence; Engineering, Electrical & Electronic
研究方向: Computer Science; Engineering
IDS 号: 024WH 
ISSN: 1057-7149 

第 29 条，共 210 条
标题: A copolymer based on benzo[1,2-b:4,5-b ']dithiophene and quinoxaline derivative for photovoltaic application 
作者: Wu, HM (Wu, Haimei); Qu, B (Qu, Bo); Cong, ZY (Cong, Zhiyuan); Liu, HL (Liu, Hongli); Tian, D (Tian, Di); Gao, BW (Gao, Bowen); An, ZW (An, Zhongwei); Gao, C (Gao, Chao); Xiao, LX (Xiao, Lixin); Chen, ZJ (Chen, Zhijian); Liu, HH (Liu, Huanhuan); Gong, QH (Gong, Qihuang); Wei, W (Wei, Wei)
来源出版物: REACTIVE & FUNCTIONAL POLYMERS  卷: 72  期: 11  页: 897-903  DOI: 10.1016/j.reactfunctpolym.2012.07.006  出版年: NOV 2012  
Web of Science 核心合集中的 "被引频次": 5 
被引频次合计: 5 
摘要: A D-A-D copolymer (PBDTQx) with a bandgap of 1.78 eV, containing alkoxy-substituted benzo[1,2-b:4,5-b']dithiophene (BDT) as donor and quinoxaline derivative (Qx) as acceptor, was synthesized by Stille coupling reaction. In order to study the photovoltaic property of PBDTQx, polymer solar cells (PSCs) were fabricated with PBDTQx as the electron donor blended with [6,6]-phenyl-C61-butyric acid methyl ester (PC61 BM) as the electron acceptor. The power conversion efficiency (PCE) of PSC was 1.01% for an optimized PBDTQx: PC61 BM ratio of 1:5, under the illumination of AM 1.5, 100 mW/cm(2). The results indicated that PBDTQx was a promising donor candidate in the application of polymer solar cells. (C) 2012 Elsevier Ltd. All rights reserved.
文献类型: Article
作者关键词: Polymer solar cell; D-A-D polymers; Heterojunction; Quinoxaline; Thiophene
KeyWords Plus: HETEROJUNCTION SOLAR-CELLS; HIGH-PERFORMANCE; POLYMER; EFFICIENCY; ADDITIVES; DONOR
Web of Science 类别: Chemistry, Applied; Engineering, Chemical; Polymer Science
研究方向: Chemistry; Engineering; Polymer Science
IDS 号: 017WO 
ISSN: 1381-5148 
电子 ISSN: 1873-166X 

第 30 条，共 210 条
标题: A probabilistic model for image representation via multiple patterns 
作者: Li, J (Li, Jun); Tao, DC (Tao, Dacheng); Li, XL (Li, Xuelong)
来源出版物: PATTERN RECOGNITION  卷: 45  期: 11  页: 4044-4053  DOI: 10.1016/j.patcog.2012.04.021  出版年: NOV 2012  
Web of Science 核心合集中的 "被引频次": 1 
被引频次合计: 1 
摘要: For image analysis, an important extension to principal component analysis (PCA) is to treat an image as multiple samples, which helps alleviate the small sample size problem. Various schemes of transforming an image to multiple samples have been proposed. Although having been shown effective in practice, the schemes are mainly based on heuristics and experience.
In this paper, we propose a probabilistic PCA model, in which we explicitly represent the transformation scheme and incorporate the scheme as a stochastic component of the model. Therefore fitting the model automatically learns the transformation. Moreover, the learned model allows us to distinguish regions that can be well described by the PCA model from those that need further treatment. Experiments on synthetic images and face data sets demonstrate the properties and utility of the proposed model. (C) 2012 Elsevier Ltd. All rights reserved.
文献类型: Article
作者关键词: Principal component analysis; Probabilistic model
KeyWords Plus: PRINCIPAL COMPONENT ANALYSIS; DIMENSIONALITY REDUCTION; FEATURE-EXTRACTION; RECOGNITION; MATRIX
Web of Science 类别: Computer Science, Artificial Intelligence; Engineering, Electrical & Electronic
研究方向: Computer Science; Engineering
IDS 号: 976KT 
ISSN: 0031-3203 

第 31 条，共 210 条
标题: Monomode optical planar and channel waveguides in Yb3+-doped silicate glasses formed by helium ion implantation 
作者: Liu, CX (Liu, Chun-Xiao); Cheng, S (Cheng, Shu); Zhao, JH (Zhao, Jin-Hua); Li, WN (Li, Wei-Nan); Wei, W (Wei, Wei); Peng, B (Peng, Bo)
来源出版物: OPTICS AND LASER TECHNOLOGY  卷: 44  期: 8  页: 2323-2326  DOI: 10.1016/j.optlastec.2012.04.033  出版年: NOV 2012  
Web of Science 核心合集中的 "被引频次": 1 
被引频次合计: 1 
摘要: We report on the fabrication of optical planar and channel waveguides in Yb3+-doped silicate glasses by triple-energy helium ion implantation at a total dose of 6 x 10(16) ions/cm(2). The dark mode spectroscopy of the planar waveguide was measured using a prism coupling arrangement. The near-field mode profiles of the planar and channel waveguides were obtained with an end-face coupling system. The refractive index profile was reconstructed using the intensity calculation method. The results indicate that a refractive index enhanced region as well as an optical barrier has been created after the beam process. After post-implantation treatments at 260 degrees C for 1 h and 310 degrees C for 30 min, the channel waveguides possessed a propagation loss of similar to 0.9 dB/cm. The acceptable guiding properties suggest that further waveguide lasers may be realized on the He-implanted Yb3+-doped silicate glass waveguides. (c) 2012 Elsevier Ltd. All rights reserved.
文献类型: Article
作者关键词: Waveguides; Ion implantation; Laser materials
KeyWords Plus: REFRACTIVE-INDEX PROFILES; DOPED FIBER; SINGLE; NM
Web of Science 类别: Optics; Physics, Applied
研究方向: Optics; Physics
IDS 号: 960EX 
ISSN: 0030-3992 

第 32 条，共 210 条
标题: Comparison of end-pumped and multi-point pumped Yb3+-doped gain guided and index antiguided fiber laser 
作者: Wu, JW (Wu, Jingwei); Zhou, EY (Zhou, Enyu); Yan, KL (Yan, Kunlun); Wei, W (Wei, Wei); Peng, B (Peng, Bo)
来源出版物: OPTICS AND LASER TECHNOLOGY  卷: 44  期: 8  页: 2371-2376  DOI: 10.1016/j.optlastec.2012.04.014  出版年: NOV 2012  
Web of Science 核心合集中的 "被引频次": 1 
被引频次合计: 1 
摘要: End-pumped and multi-point pumped Yb3+-doped gain guided and index antiguided (GG+IAG) fiber laser are analyzed by solving the rate equations and 3-D thermal conduction equations. Simulation results show that the multi-point pumped scheme can provide lower operating temperature and better temperature uniformity. Meanwhile, fabrication complexity, loss resulted from pump point should be taken into consideration in the practical design. Crown Copyright (c) 2012 Published by Elsevier Ltd. All rights reserved.
文献类型: Article
作者关键词: Gain-guided index-antiguided fiber; Multi-point pumped; Thermal effects
KeyWords Plus: DOUBLE-CLAD FIBER; AMPLIFIER
Web of Science 类别: Optics; Physics, Applied
研究方向: Optics; Physics
IDS 号: 960EX 
ISSN: 0030-3992 
电子 ISSN: 1879-2545 

第 33 条，共 210 条
标题: Fluorescence volume imaging with an axicon: simulation study based on scalar diffraction method 
作者: Zheng, JJ (Zheng, Juanjuan); Yang, YL (Yang, Yanlong); Lei, M (Lei, Ming); Yao, BL (Yao, Baoli); Gao, P (Gao, Peng); Ye, T (Ye, Tong)
来源出版物: APPLIED OPTICS  卷: 51  期: 30  页: 7236-7245  DOI: 10.1364/AO.51.007236  出版年: OCT 20 2012  
Web of Science 核心合集中的 "被引频次": 3 
被引频次合计: 3 
摘要: In a two-photon excitation fluorescence volume imaging (TPFVI) system, an axicon is used to generate a Bessel beam and at the same time to collect the generated fluorescence to achieve large depth of field. A slice-by-slice diffraction propagation model in the frame of the angular spectrum method is proposed to simulate the whole imaging process of TPFVI. The simulation reveals that the Bessel beam can penetrate deep in scattering media due to its self-reconstruction ability. The simulation also demonstrates that TPFVI can image a volume of interest in a single raster scan. Two-photon excitation is crucial to eliminate the signals that are generated by the side lobes of Bessel beams; the unwanted signals may be further suppressed by placing a spatial filter in the front of the detector. The simulation method will guide the system design in improving the performance of a TPFVI system. (C) 2012 Optical Society of America
PubMed ID: 23089777 
文献类型: Article
KeyWords Plus: EXTENDED DEPTH; BESSEL BEAMS; CONFOCAL MICROSCOPY; 2-PHOTON MICROSCOPY; PROPAGATION; FIELD; ILLUMINATION; GENERATION; MEDIA; FOCUS
Web of Science 类别: Optics
研究方向: Optics
IDS 号: 028OE 
ISSN: 1559-128X 
电子 ISSN: 2155-3165 

第 34 条，共 210 条
标题: Proton-implanted optical planar waveguides in Yb3+-doped silicate glasses 
作者: Liu, CX (Liu, Chun-Xiao); Cheng, S (Cheng, Shu); Guo, HT (Guo, Hai-Tao); Li, WN (Li, Wei-Nan); Liu, XH (Liu, Xiu-Hong); Wei, W (Wei, Wei); Peng, B (Peng, Bo)
来源出版物: NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION B-BEAM INTERACTIONS WITH MATERIALS AND ATOMS  卷: 289  页: 18-21  DOI: 10.1016/j.nimb.2012.08.004  出版年: OCT 15 2012  
Web of Science 核心合集中的 "被引频次": 1 
被引频次合计: 1 
摘要: We report on the characterization of planar waveguides in Yb3+-doped silicate glasses fabricated by double-energy proton implantation at a total dose of 3 x 10(16) ions/cm(2). The dark mode spectroscopy and near-field mode profile were evaluated by the prism coupling and end-face coupling methods, respectively. The results indicate that a refractive index enhanced region as well as an optical barrier has been created after the beam process. We propose the ion exchange mechanism between the proton and Na+ ions to illustrate the optical barrier and discuss its influence. (C) 2012 Elsevier B.V. All rights reserved.
文献类型: Article
作者关键词: Waveguide; Ion implantation; Fluorescence; Ytterbium-doped glass
KeyWords Plus: PHOSPHATE-GLASS; LASER; FABRICATION; AMPLIFIERS
Web of Science 类别: Instruments & Instrumentation; Nuclear Science & Technology; Physics, Atomic, Molecular & Chemical; Physics, Nuclear
研究方向: Instruments & Instrumentation; Nuclear Science & Technology; Physics
IDS 号: 033AU 
ISSN: 0168-583X 

第 35 条，共 210 条
标题: Spoof four-wave mixing for all-optical wavelength conversion 
作者: Gong, YK (Gong, Yongkang); Huang, JG (Huang, Jungang); Li, K (Li, Kang); Copner, N (Copner, Nigel); Martinez, JJ (Martinez, J. J.); Wang, LR (Wang, Leirang); Duan, T (Duan, Tao); Zhang, WF (Zhang, Wenfu); Loh, WH (Loh, W. H.)
来源出版物: OPTICS EXPRESS  卷: 20  期: 21  页: 24030-24037  DOI: 10.1364/OE.20.024030  出版年: OCT 8 2012  
Web of Science 核心合集中的 "被引频次": 4 
被引频次合计: 4 
摘要: We present for the first time an all-optical wavelength conversion (AOWC) scheme supporting modulation format independency without requiring phase matching. The new scheme is named "spoof" four wave mixing (SFWM) and in contrast to the well-known FWM theory, where the induced dynamic refractive index grating modulates photons to create a wave at a new frequency, the SFWM is different in that the dynamic refractive index grating is generated in a nonlinear Bragg Grating (BG) to excite additional reflective peaks at either side of the original BG bandgap in reflection spectrum. This fundamental difference enable the SFWM to avoid the intrinsic shortcoming of stringent phase matching required in the conventional FWM, and allows AOWC with modulation format transparency and ultrabroad conversion range, which may have great potential applications for next generation of all-optical networks. (C) 2012 Optical Society of America
PubMed ID: 23188370 
文献类型: Article
KeyWords Plus: SILICON WAVE-GUIDES; FREQUENCY-CONVERSION; MODULATION; NETWORK; SIGNAL; FIBER; NANOWAVEGUIDES; AMPLIFIER; SPEED; GAIN
Web of Science 类别: Optics
研究方向: Optics
IDS 号: 022JP 
ISSN: 1094-4087 

第 36 条，共 210 条
标题: Research of the navigation accuracy for the X-ray pulsar navigation system 
作者: Wang, P (Wang Peng); Zhao, BS (Zhao Bao-Sheng); Sheng, LZ (Sheng Li-Zhi); Hu, HJ (Hu Hui-Jun); Yan, QR (Yan Qiu-Rong)
来源出版物: ACTA PHYSICA SINICA  卷: 61  期: 20  文献号: 209702  出版年: OCT 2012  
Web of Science 核心合集中的 "被引频次": 3 
被引频次合计: 5 
摘要: In order to improve the navigation accuracy of the X-ray pulsar navigation system, in this paper we propose a constant fraction timing method based on the low-pass filter to measure the arrival time of the X-ray pulse in X-ray pulsar navigation. According to the technical scheme, the timing accuracies and dead times of original peaking timing and the improved constant fraction timing are measured. Experimental results indicate that the timing accuracy and the dead time of the peaking timing system are 18 ns and 4750 ns, the timing accuracy and the dead time of the constant fraction timing system are 0.78 ns and 105 ns. The timing accuracy and the dead time of constant fraction timing system are significantly improved compared with those of the peaking timing system. In the X-ray pulsar navigation system, the cumulative pulse profile of the X-ray pulse is constructed in the two different timing systems through measuring the arrival time of the X-ray photon. Experimental results indicate that compared with using the peaking timing system, the cumulative pulse profile of the X-ray pulse using the improved constant fraction timing system is improved obviously, therefore, the navigation accuracy could be improved by using the constant fraction timing system.
文献类型: Article
作者关键词: detectors; X-ray pulsar navigation; timing accuracy; dead time
Web of Science 类别: Physics, Multidisciplinary
研究方向: Physics
IDS 号: 043EJ 
ISSN: 1000-3290 

第 37 条，共 210 条
标题: Finger capacitance of a terahertz photomixer in low-temperature-grown GaAs using the finite element method 
作者: Chen, LC (Chen Long-Chao); Fan, WH (Fan Wen-Hui)
来源出版物: CHINESE PHYSICS B  卷: 21  期: 10  文献号: 104101  DOI: 10.1088/1674-1056/21/10/104101  出版年: OCT 2012  
Web of Science 核心合集中的 "被引频次": 0 
被引频次合计: 0 
摘要: Interdigitated finger capacitance of a continuous-wave terahertz photomixer is calculated using the finite element method. For the frequently used electrode width (0.2 mu m) and gap width (1.8 mu m), the finger capacitance increases quasi-quadratically with the number of electrodes increasing. The quasi-quadratic dependence can be explained by a sequence of lumped capacitors connected in parallel. For a photomixer composed of 10 electrodes and 9 photoconductive gaps, the finger capacitance increases as the gap width increases at a small electrode width, and follows the reverse trend at a large electrode width. For a constant electrode width, the finger capacitance first decreases and then slightly increases as the gap broadens until the smallest finger capacitance is formed. We also investigate the finger capacitances at different electrode and gap configurations with the 8 mu m x 8 mu m photomixer commonly used in previous studies. These calculations lead to a better understanding of the finger capacitance affected by the finger parameters, and should lead to terahertz photomixer optimization.
文献类型: Article
作者关键词: terahertz photomixer; continuous-wave; interditated finger capacitance; finite element method
KeyWords Plus: CONTINUOUS-WAVE TERAHERTZ; DIODE-LASERS
Web of Science 类别: Physics, Multidisciplinary
研究方向: Physics
IDS 号: 020NF 
ISSN: 1674-1056 

第 38 条，共 210 条
标题: Target classification using SIFT sequence scale invariants 
作者: Zhu, XF (Zhu, Xufeng); Ma, CW (Ma, Caiwen); Liu, B (Liu, Bo); Cao, XQ (Cao, Xiaoqian)
来源出版物: JOURNAL OF SYSTEMS ENGINEERING AND ELECTRONICS  卷: 23  期: 5  页: 633-639  DOI: 10.1109/JSEE.2012.00079  出版年: OCT 2012  
Web of Science 核心合集中的 "被引频次": 0 
被引频次合计: 2 
摘要: On the basis of scale invariant feature transform (SIFT) descriptors, a novel kind of local invariants based on SIFT sequence scale (SIFT-SS) is proposed and applied to target classification. First of all, the merits of using an SIFT algorithm for target classification are discussed. Secondly, the scales of SIFT descriptors are sorted by descending as SIFT-SS, which is sent to a support vector machine (SVM) with radial based function (RBF) kernel in order to train SVM classifier, which will be used for achieving target classification. Experimental results indicate that the SIFT-SS algorithm is efficient for target classification and can obtain a higher recognition rate than affine moment invariants (AMI) and multi-scale auto-convolution (MSA) in some complex situations, such as the situation with the existence of noises and occlusions. Moreover, the computational time of SIFT-SS is shorter than MSA and longer than AMI.
文献类型: Article
作者关键词: target classification; scale invariant feature transform descriptors; sequence scale; support vector machine
KeyWords Plus: RECOGNITION
Web of Science 类别: Automation & Control Systems; Engineering, Electrical & Electronic; Operations Research & Management Science
研究方向: Automation & Control Systems; Engineering; Operations Research & Management Science
IDS 号: 026KK 
ISSN: 1004-4132 

第 39 条，共 210 条
标题: Highly stable, passively mode-locked fiber laser with low pump power for subpicosecond pulse generation 
作者: Tang, DL (Tang, Dingkang); Zhang, JG (Zhang, Jian-Guo); Liu, YS (Liu, Yuanshan)
来源出版物: LASER PHYSICS  卷: 22  期: 10  页: 1586-1589  DOI: 10.1134/S1054660X12100052  出版年: OCT 2012  
Web of Science 核心合集中的 "被引频次": 0 
被引频次合计: 0 
摘要: We present the design of highly stable, passively mode-locked fiber lasers which are based on a simple configuration and require a low pump power for the generation of optical pulses with subpicosecond pulsewidth. Our designed fiber laser uses a semiconductor saturable absorber mirror to realize the self-starting, passive mode locking at a low pump power of 29 mW, with which a stable optical pulse train is obtained at the fundamental repetition rate of 52.5 MHz and the central wavelength of 1557 nm. The output mode-locked optical pulses have a pulsewidth of 881 fs and an average output power of 1.78 mW, respectively.
文献类型: Article
KeyWords Plus: RING LASER; DISPERSION; LOCKING
Web of Science 类别: Optics; Physics, Applied
研究方向: Optics; Physics
IDS 号: 015XY 
ISSN: 1054-660X 

第 40 条，共 210 条
标题: Influence of Package Structure on the Performance of the Single Emitter Diode Laser 
作者: Li, XN (Li, Xiaoning); Zhang, YX (Zhang, Yanxin); Wang, JW (Wang, Jingwei); Xiong, LL (Xiong, Lingling); Zhang, P (Zhang, Pu); Nie, ZQ (Nie, Zhiqiang); Wang, ZF (Wang, Zhenfu); Liu, H (Liu, Hui); Liu, XS (Liu, Xingsheng)
来源出版物: IEEE TRANSACTIONS ON COMPONENTS PACKAGING AND MANUFACTURING TECHNOLOGY  卷: 2  期: 10  页: 1592-1599  DOI: 10.1109/TCPMT.2012.2207456  出版年: OCT 2012  
Web of Science 核心合集中的 "被引频次": 1 
被引频次合计: 1 
摘要: The package structure critically influences the major characteristics of semiconductor lasers, such as thermal behavior, output power, wavelength, and far-field distribution. In this paper, a new single emitter package structure called F-mount is designed and compared with the conventional package structure C-mount. The influence of package structure on their performances is characterized and analyzed. The thermal resistances of lasers with different package structures are calculated through simulation, and are contrasted with experimental results. Some devices are also tested for the maximum output power level. Under the continuous wave (CW) condition, the maximum power of F-mount reaches 12.6 W at 808 nm while the output power only reaches 10.9 W for C-mount. Under the condition of 0.5% duty cycle (100 mu s, 50 Hz), the catastrophic optical mirror damage level reaches 58.7 W at 74 A for F-mount, and 54.8 W at 57 A for C-mount are reported for the first time. It is experimentally found that there is an obvious wavelength difference between the two type structure lasers: about 1.37 nm in CW mode and 2.89 nm in quasi CW mode. Theoretical analysis shows that red-shift and blue-shift is a result of external strain in the package process of F-mount and C-mount, respectively. It is also found that the package structure has an effect on the divergence angle of slow axis far fields, but little impact on that of fast axis far fields. The analysis shows that package structure has a strong influence on the performance of the laser; therefore, the package should be optimized to achieve better performance for some special applications.
文献类型: Article
作者关键词: Component architectures; semiconductor device packaging
KeyWords Plus: POWER SEMICONDUCTOR-LASERS; INDIUM; STRAIN
Web of Science 类别: Engineering, Manufacturing; Engineering, Electrical & Electronic; Materials Science, Multidisciplinary
研究方向: Engineering; Materials Science
IDS 号: 019HQ 
ISSN: 2156-3950 

第 41 条，共 210 条
标题: Influence of Ag nanoparticles on luminescent performance of SiO2:Tb3+ nanomaterials 
作者: Zhang, DK (Zhang, Dekai); Hu, XY (Hu, Xiaoyun); Ji, RN (Ji, Ruonan); Zhan, SC (Zhan, Suchang); Gao, JH (Gao, Jianhua); Yan, ZY (Yan, Zhiyun); Liu, EZ (Liu, Enzhou); Fan, J (Fan, Jun); Hou, X (Hou, Xun)
来源出版物: JOURNAL OF NON-CRYSTALLINE SOLIDS  卷: 358  期: 20  页: 2788-2792  DOI: 10.1016/j.jnoncrysol.2012.07.004  出版年: OCT 1 2012  
Web of Science 核心合集中的 "被引频次": 3 
被引频次合计: 3 
摘要: Tb3+ single-doped SiO2 (SiO2:Tb3+) and Tb3+, Ag co-doped SiO2 (SiO2:Tb3+-Ag) nanostructured luminescent materials were prepared by a modified Stober method. Their microstructure and optical property were investigated using scanning electron microscopy, ultraviolet visible absorption and photoluminescence spectrophotometry. Results show that the samples are composed of well-dispersed near-spherical particles with a diameter about 50 nm, the highest fluorescence intensity is obtained when the doping concentration of Tb3+ is 4.86 mol%, the corresponding internal quantum efficiency is 13.6% and the external quantum efficiency is 8.2%. The experimental results indicate that Ag nanoparticles can greatly enhance the light absorption at 226 nm and the light emission at 543 nm of SiO2:Tb3+-Ag, and the fluorescence lifetime reduces with increasing Ag concentration in SiO2:Tb3+-Ag. Additionally, the present results indicate that fluorescence enhancement is attributed to the local field enhancement and the increased radiative decay rates induced by Ag nanoparticles. (c) 2012 Elsevier B.V. All rights reserved.
文献类型: Article
作者关键词: Rare earth doping; Localized surface plasmon resonance; Radiative decay rates; Luminescence
KeyWords Plus: SILVER ISLAND FILMS; ENERGY-TRANSFER; ENHANCED FLUORESCENCE; RESONANCE; SPHERES; EU3+
Web of Science 类别: Materials Science, Ceramics; Materials Science, Multidisciplinary
研究方向: Materials Science
IDS 号: 018GE 
ISSN: 0022-3093 

第 42 条，共 210 条
标题: Optical sorting of particles by dual-channel line optical tweezers 
作者: Ma, BH (Ma, Baiheng); Yao, BL (Yao, Baoli); Peng, F (Peng, Fei); Yan, SH (Yan, Shaohui); Lei, M (Lei, Ming); Rupp, R (Rupp, Romano)
来源出版物: JOURNAL OF OPTICS  卷: 14  期: 10  文献号: 105702  DOI: 10.1088/2040-8978/14/10/105702  出版年: OCT 2012  
Web of Science 核心合集中的 "被引频次": 1 
被引频次合计: 1 
摘要: A novel configuration of dual-channel line optical tweezers with a 'Y' shape is constructed for sorting of particles within a microfluidic chip. When yeast cells with different size pass the intersection of the specially designed line optical tweezers, they are separated and transported to different channels due to a difference in the forces exerted by the line tweezers that depends on the size of the cells. The influences of some experimental conditions, such as laser power and flow velocity, on the sorting efficiency are discussed.
文献类型: Article
作者关键词: line optical tweezers; optical sorting; microfluidic chip
KeyWords Plus: DIODE-LASER BARS; PATTERN-FORMATION; BEAM; MANIPULATION; MICROMANIPULATION; DEFLECTION; LATTICES; COLLOIDS; SYSTEM
Web of Science 类别: Optics
研究方向: Optics
IDS 号: 020MB 
ISSN: 2040-8978 

第 43 条，共 210 条
标题: Formation and evolution of passively mode-locked fiber soliton lasers operating in a dual-wavelength regime 
作者: Mao, D (Mao, Dong); Lu, H (Lu, Hua)
来源出版物: JOURNAL OF THE OPTICAL SOCIETY OF AMERICA B-OPTICAL PHYSICS  卷: 29  期: 10  页: 2819-2826  出版年: OCT 2012  
Web of Science 核心合集中的 "被引频次": 2 
被引频次合计: 2 
摘要: formation and evolution of dual-wavelength solitons in passively mode-locked fiber soliton lasers are investigated both numerically and experimentally. By solving the Ginzburg-Landau equation and taking the gain profile into account, mode-locked soliton emissions at 1532 and 1555 nm are achieved simultaneously. Numerical results show that the two solitons exhibit the same intensity and duration, indicating that the dual-wavelength pulses possess the soliton energy quantization effect. In the process of pulse-pulse collisions, two solitons pass through each other and maintain their properties, qualitatively distinct from single-wavelength solitons that never overlap each other. The dual-wavelength mode-locked operation evolves into single-wavelength mode locking with the decrease of the pumping strength. The dual-peak gain spectrum of erbium-doped fiber and the birefringence-induced cavity filtering effect play crucial roles in the formation of dual-wavelength solitons. Numerical results agree well with analytical solutions and experimental observations. Our study provides an optional method of measuring the fiber dispersion by means of the dual-wavelength solitons. (c) 2012 Optical Society of America
文献类型: Article
KeyWords Plus: ERBIUM-DOPED FIBER; PHOTONIC CRYSTAL FIBER; NONLINEAR POLARIZATION ROTATION; GINZBURG-LANDAU EQUATION; NET-NORMAL-DISPERSION; DISSIPATIVE SOLITONS; ANOMALOUS-DISPERSION; BRAGG GRATINGS; RING LASER; PULSES
Web of Science 类别: Optics
研究方向: Optics
IDS 号: 017KG 
ISSN: 0740-3224 

第 44 条，共 210 条
标题: Color-stable deep red-emitting OLEDs based on a soluble terpolyrner containing fluorene, thiophene and benzothiadiazole units 
作者: Qu, B (Qu, Bo); Feng, LM (Feng, Limin); Yang, HS (Yang, Hongsheng); Gao, Z (Gao, Zhi); Gao, C (Gao, Chao); Chen, ZJ (Chen, Zhijian); Xiao, LX (Xiao, Lixin); Gong, QH (Gong, Qihuang)
来源出版物: SYNTHETIC METALS  卷: 162  期: 17-18  页: 1587-1593  DOI: 10.1016/j.synthmet.2012.06.021  出版年: OCT 2012  
Web of Science 核心合集中的 "被引频次": 1 
被引频次合计: 1 
摘要: A novel soluble terpolymer (P8FO-Th-BT) containing 9,9-dioctylfluorene, thiophene, and 2,1,3-benzothiadiazole units were synthesized by Still coupling reaction. The single layer and multi-layer organic light emitting diodes (OLEDs) based on P8FO-Th-BT was fabricated. A deep red-emission device with the configuration of ITO/poly(3,4-ethylenedioxythiophene)-polystyrene sulfonate (PEDOT:PSS)/P8FO-Th-BT:N,N'-di(3-methylphenyl)-N,N'-diphenyl-(1,1'-biphenyl)-4,4-diamine (TPD) (weight ratio being 1:1)/2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline (BCP, 15 nm)/tris(8-hydroxyquinoline) aluminum (Alq(3), 15 nm)/LiF(5 angstrom)/Al(150 nm) was obtained, and the maximum luminance was measured to be 226 cd/m(2) at the bias voltage of 10V. The electroluminescent peak located at 708 nm, and the spectrum covered both the red and infrared regions. Moreover, the Commission International De L'Eclairage (CIE) chromaticity coordinates of the device were inalterable when the bias voltage varied, which was beneficial to the application on display. Crown Copyright (c) 2012 Published by Elsevier B.V. All rights reserved.
文献类型: Article
作者关键词: Deep red-emitting OLED; Organic electroluminescence; Terpolymer; Fluorene; Benzothiadiazole; Thiophene
KeyWords Plus: ORGANIC ELECTROLUMINESCENT DEVICES; ELECTRON INJECTION LAYER; HIGH-EFFICIENCY; DIODES; POLYMERS; COPOLYMERS; PHOTOLUMINESCENCE; COMPLEX; BLEND
Web of Science 类别: Materials Science, Multidisciplinary; Physics, Condensed Matter; Polymer Science
研究方向: Materials Science; Physics; Polymer Science
IDS 号: 015ZY 
ISSN: 0379-6779 

第 45 条，共 210 条
标题: Unidirectional excitation of surface plasmon polaritons in T-shaped waveguide with nanodisk resonator 
作者: Wang, GX (Wang, Guoxi); Lu, H (Lu, Hua)
来源出版物: OPTICS COMMUNICATIONS  卷: 285  期: 21-22  页: 4190-4193  DOI: 10.1016/j.optcom.2012.07.019  出版年: OCT 1 2012  
Web of Science 核心合集中的 "被引频次": 4 
被引频次合计: 4 
摘要: The unidirectional excitation of surface plasmon polaritons (SPPs) in a novel configuration is numerically investigated by the finite-difference time-domain method. It is found that the transmission varies periodically with the increase of distance between the nanodisk resonator and horizontal nanoslit, which can be interpreted by the interference theory. The operating wavelength of this structure can be tuned by altering the refractive index of the nanodisk resonator. This subwavelength-scale structure exhibits high transmission (similar to 58%) due to the constructive interference of the SPP modes, and thus can find important applications on the manipulation of SPP excitation in highly integrated optical circuits. (C) 2012 Elsevier B.V. All rights reserved.
文献类型: Article
作者关键词: Surface plasmon polariton; Photonic integrated circuits; Finite-difference time-domain
KeyWords Plus: GRATINGS; BISTABILITY; SCALE
Web of Science 类别: Optics
研究方向: Optics
IDS 号: 010GB 
ISSN: 0030-4018 

第 46 条，共 210 条
标题: A Slot Micro/Nano Fiber With Elliptical Low-Index Core 
作者: Zhang, WF (Zhang, Wenfu); Mu, JW (Mu, Jian-Wei); Huang, WP (Huang, Wei-Ping); Zhao, W (Zhao, Wei)
来源出版物: IEEE PHOTONICS JOURNAL  卷: 4  期: 5  页: 1610-1621  DOI: 10.1109/JPHOT.2012.2212241  出版年: OCT 2012  
Web of Science 核心合集中的 "被引频次": 0 
被引频次合计: 0 
摘要: A slot micro/nano optical fiber with elliptical low-index core, referred to as the elliptical-slot micro/nano fiber (ESMNF), is studied systematically in great detail in this paper. It is demonstrated that the ESMNF can confine most of the light in the low-index region and hence lead to large field enhancement. Benefiting from the large low-index power confinement factor and the field enhancement, the ESMNF also yields significant nonlinearity enhancement by the proper selection of materials. In addition, large birefringence between the two fundamental polarized modes is observed, due to the breakage of the circular symmetry for the core. The nonlinearity and low-index confinement properties of a more practical elliptical-slot embedded suspended microstructure fiber are also studied.
文献类型: Article
作者关键词: Fiber optics; fiber design and fabrication; nonlinear optics; fibers
KeyWords Plus: MICROSTRUCTURED OPTICAL-FIBERS; SUBWAVELENGTH-DIAMETER SILICA; PHOTONIC CRYSTAL FIBERS; SUSPENDED-CORE; CONFINING LIGHT; WAVE-GUIDES; MICROFIBER; FIELD; DESIGN; AIR
Web of Science 类别: Engineering, Electrical & Electronic; Optics; Physics, Applied
研究方向: Engineering; Optics; Physics
IDS 号: 995NE 
ISSN: 1943-0655 

第 47 条，共 210 条
标题: Image encryption based on the random rotation operation in the fractional Fourier transform domains 
作者: Liu, ZJ (Liu, Zhengjun); Li, S (Li, She); Yang, M (Yang, Meng); Liu, WY (Liu, Wanyu); Liu, ST (Liu, Shutian)
来源出版物: OPTICS AND LASERS IN ENGINEERING  卷: 50  期: 10  页: 1352-1358  DOI: 10.1016/j.optlaseng.2012.05.021  出版年: OCT 2012  
Web of Science 核心合集中的 "被引频次": 19 
被引频次合计: 19 
摘要: A kind of image encryption scheme is presented by using a rotation operation being regarded as the scrambling scheme of the pixels. The rotation operation is composed of rotation center, radii and angle. For the data of phase and amplitude of complex number, the rotation operation is performed with random controlling parameters iteratively. The parameters are random and serve as the key of this encryption method. Subsequently, the fractional Fourier transform is introduced to alter the values of image pixel. The process mentioned above will be achieved many times for enhancing the security of the proposed algorithm. Numerical simulation is given to demonstrate the validity and performance of the image hiding procedure. (C) 2012 Elsevier Ltd. All rights reserved.
文献类型: Article
作者关键词: Random rotation operation; Pixel scrambling; Amplitude encoding; Phase encoding
KeyWords Plus: ARNOLD TRANSFORM; PLAINTEXT ATTACK; INTERFERENCE; ALGORITHM
Web of Science 类别: Optics
研究方向: Optics
IDS 号: 982IS 
ISSN: 0143-8166 

第 48 条，共 210 条
标题: Video super-resolution with 3D adaptive normalized convolution 
作者: Zhang, KB (Zhang, Kaibing); Mu, GW (Mu, Guangwu); Yuan, Y (Yuan, Yuan); Gao, XB (Gao, Xinbo); Tao, DC (Tao, Dacheng)
来源出版物: NEUROCOMPUTING  卷: 94  页: 140-151  DOI: 10.1016/j.neucom.2012.03.012  出版年: OCT 1 2012  
Web of Science 核心合集中的 "被引频次": 4 
被引频次合计: 4 
摘要: The classic multi-image-based super-resolution (SR) methods typically take global motion pattern to produce one or multiple high-resolution (HR) versions from a set of low-resolution (LR) images. However, due to the influence of aliasing and noise, it is difficult to obtain highly accurate registration with sub-pixel accuracy. Moreover, in practical applications, the global motion pattern is rarely found in the real LR inputs. In this paper, to surmount or at least reduce the aforementioned problems, we develop a novel SR framework for video sequence by extending the traditional 2-dimentional (2D) normalized convolution (NC) to 3-dimentional (3D) case. In the proposed framework, to bypass explicit motion estimation, we estimate a target pixel by taking a weighted average of pixels from its neighborhood. We further up-scale the input video sequence in temporal dimension based on the extended 3D NC and hence more video frames can be generated. Fundamental experiments demonstrate the effectiveness of the proposed SR framework both quantitatively and perceptually. (C) 2012 Elsevier B.V. All rights reserved.
文献类型: Article
作者关键词: Normalized convolution (NC); Motion estimation; Video super-resolution (SR)
KeyWords Plus: HIGH-RESOLUTION IMAGE; RECONSTRUCTION ALGORITHM; MOTION ESTIMATION; REGRESSION
Web of Science 类别: Computer Science, Artificial Intelligence
研究方向: Computer Science
IDS 号: 982ZZ 
ISSN: 0925-2312 

第 49 条，共 210 条
标题: Picosecond laser-induced formation of spikes in a single crystal superalloy 
作者: Zhang, W (Zhang, Wei); Cheng, GH (Cheng, Guanghua); Feng, Q (Feng, Qiang); Cao, LM (Cao, Lamei)
来源出版物: APPLIED SURFACE SCIENCE  卷: 258  期: 23  页: 9452-9456  DOI: 10.1016/j.apsusc.2012.02.056  出版年: SEP 15 2012  
Web of Science 核心合集中的 "被引频次": 5 
被引频次合计: 5 
摘要: The characteristics of laser-induced periodic surface structures (LIPSS) were investigated after laser irradiation with different pulse duration under a certain range of laser fluence (0.25 <= Phi <= 1.91 J/cm(2)) and pulse number (11 <= N <= 560). Spikes were generated by picosecond laser irradiation in ambient air, in comparison with only periodic ripple structures introduced by nanosecond and femtosecond laser irradiation. Microstructural investigations indicate that these spikes were initiated by the fragment of periodic ripple ridges or corrugation on the smooth surface with subsequent pulses, and their separation increased with increasing the laser fluence. Surface capillary waves associated with the resolidification process can be employed to explain the formation of spikes by picosecond laser irradiation. (c) 2012 Elsevier B.V. All rights reserved.
文献类型: Article
作者关键词: Picosecond laser; Ripples; Spikes; Capillary waves
KeyWords Plus: PERIODIC SURFACE-STRUCTURE; ABLATION; SILICON; REGIMES
Web of Science 类别: Chemistry, Physical; Materials Science, Coatings & Films; Physics, Applied; Physics, Condensed Matter
研究方向: Chemistry; Materials Science; Physics
IDS 号: 985CU 
ISSN: 0169-4332 

第 50 条，共 210 条
标题: Plasmonic nanosensor based on Fano resonance in waveguide-coupled resonators 
作者: Lu, H (Lu, Hua); Liu, XM (Liu, Xueming); Mao, D (Mao, Dong); Wang, GX (Wang, Guoxi)
来源出版物: OPTICS LETTERS  卷: 37  期: 18  页: 3780-3782  出版年: SEP 15 2012  
Web of Science 核心合集中的 "被引频次": 30 
被引频次合计: 30 
摘要: We propose a plasmonic nanosensor based on Fano resonance in the strong-confinement metal-dielectric-metal waveguide side-coupled with a pair of nanoresonators. Due to the coherent interference of the splitting discrete and quasi-continuum modes, the reflection spectrum possesses a sharp asymmetric Fano resonance dip, which is dependent on the cavity-cavity phase and the refractive index change of the dielectric. The physical features contribute to a highly efficient plasmonic sensor for refractive index sensing. The nanosensor yields a sensitivity of similar to 900 nm/RIU and a figure of merit of similar to 500, remarkable values compared with those of plasmonic sensors supported by perfect absorbers. (C) 2012 Optical Society of America
PubMed ID: 23041857 
文献类型: Article
KeyWords Plus: INDUCED TRANSPARENCY; NANOSCALE; LINESHAPE
Web of Science 类别: Optics
研究方向: Optics
IDS 号: 009SU 
ISSN: 0146-9592 

第 51 条，共 210 条
标题: Slow-light element for tunable time delay based on optical microcoil resonator 
作者: Ma, CJ (Ma, Chengju); Ren, LY (Ren, Liyong); Xu, YP (Xu, Yiping)
来源出版物: APPLIED OPTICS  卷: 51  期: 26  页: 6295-6300  DOI: 10.1364/AO.51.006295  出版年: SEP 10 2012  
Web of Science 核心合集中的 "被引频次": 3 
被引频次合计: 3 
摘要: We propose a simple and compact slow-light element by use of an optical microcoil resonator (OMR) constituted by two microfiber coils. Based on the matrix exponential method, we solve the coupled-wave equations of the OMR with n turns of microfiber coils and obtain a general solution. Simulations indicate that a tunable slow-light propagation can be obtained by controlling the coupling coefficient between the two adjacent microfiber coils by means of regulating the voltage applied to the ferroelectric crystal. A slow-light time delay up to 62 ps with a bandwidth of 0.4 nm is performed at the wavelength around 1.5 mu m. (C) 2012 Optical Society of America
PubMed ID: 22968266 
文献类型: Article
KeyWords Plus: STIMULATED BRILLOUIN-SCATTERING; SUBWAVELENGTH-DIAMETER SILICA; MICROFIBER COIL RESONATORS; WAVE-GUIDES; REFRACTOMETRIC SENSOR; FIBER; PROPAGATION; DISPERSION; CHIP
Web of Science 类别: Optics
研究方向: Optics
IDS 号: 006ZP 
ISSN: 1559-128X 
电子 ISSN: 2155-3165 

第 52 条，共 210 条
标题: High-power and widely tunable Tm-doped fiber laser at 2 mu m 
作者: Guo, CZ (Guo, Chengzheng); Shen, DY (Shen, Deyuan); Long, JY (Long, Jingyu); Wang, F (Wang, Fei)
来源出版物: CHINESE OPTICS LETTERS  卷: 10  期: 9  文献号: 091406  DOI: 10.3788/COL201210.091406  出版年: SEP 10 2012  
Web of Science 核心合集中的 "被引频次": 11 
被引频次合计: 11 
摘要: Efficient, high-power, and widely tunable Tm-doped fiber lasers cladding-pumped by diode lasers at 791 nm are demonstrated by use of an external cavity containing a diffraction grating. A maximum output power of 62 W is obtained at 2 004 nm for 140 W of launched pump power, corresponding to a slope efficiency of 48% with respect to launched pump power. The operating wavelength is tunable over 200 nm (1 895 to 2 109 nm), with >52 W of output power over a tuning range of 140 nm (1 926 to 2 070 nm). Prospects for further improvement in output power, lasing efficiency, and tuning range are considered.
文献类型: Article
KeyWords Plus: BRAGG GRATINGS; ER
Web of Science 类别: Optics
研究方向: Optics
IDS 号: 005XC 
ISSN: 1671-7694 

第 53 条，共 210 条
标题: Dispersionless slow light in MIM waveguide based on a plasmonic analogue of electromagnetically induced transparency 
作者: Wang, GX (Wang, Guoxi); Lu, H (Lu, Hua); Liu, XM (Liu, Xueming)
来源出版物: OPTICS EXPRESS  卷: 20  期: 19  页: 20902-20907  DOI: 10.1364/OE.20.020902  出版年: SEP 10 2012  
Web of Science 核心合集中的 "被引频次": 37 
被引频次合计: 37 
摘要: We have proposed a metal-insulator-metal (MIM) waveguide system, which exhibits a significant slow-light effect, based on a plasmonic analogue of electromagnetically induced transparency (EIT). By appropriately adjusting the distance between the two stubs of a unit cell, a flat band corresponding to nearly constant group index over a broad bandwidth of 8.6 THz can be achieved. The analytical results show that the group velocity dispersion (GVD) parameter can reach zero and normalized delay-bandwidth product (NDBP) is more than 0.522. Finite-Difference Time-Domain (FDTD) simulations show that the incident pulse can be slowed down without distortion owing to the low dispersion. The proposed compact configuration can avoid the distortion of signal pulse, and thus may find potential applications in plasmonic slow-light systems, especially optical buffers. (C) 2012 Optical Society of America
PubMed ID: 23037214 
文献类型: Article
KeyWords Plus: DELAY-BANDWIDTH PRODUCT; NANODISK RESONATORS; SURFACE-PLASMONS; OPTICAL BUFFERS; STUB STRUCTURE
Web of Science 类别: Optics
研究方向: Optics
IDS 号: 007CE 
ISSN: 1094-4087 

第 54 条，共 210 条
标题: Observation of dual-wavelength dissipative solitons in a figure-eight erbium-doped fiber laser 
作者: Yun, L (Yun, Ling); Liu, XM (Liu, Xueming); Mao, D (Mao, Dong)
来源出版物: OPTICS EXPRESS  卷: 20  期: 19  页: 20992-20997  DOI: 10.1364/OE.20.020992  出版年: SEP 10 2012  
Web of Science 核心合集中的 "被引频次": 23 
被引频次合计: 23 
摘要: We report on the generation of dual-wavelength dissipative solitons (DSs) in a passively mode-locked figure-eight fiber laser operating in the net-normal dispersion regime. DSs with central wavelengths of 1572 and 1587 nm can be achieved simultaneously or respectively. The dual-wavelength DSs, traveling at different round-trip time, exhibit double-rectangular spectral profile. The intensities of two mode-locked spectra decrease or increase simultaneously after passing through a polarization beam splitter, indicating that the dual-wavelength DSs almost share the same polarization state. Experimental results demonstrated that dual-wavelength mode locking strongly depends on birefringence-induced filtering effect. (C) 2012 Optical Society of America
PubMed ID: 23037222 
文献类型: Article
KeyWords Plus: BRAGG GRATINGS; DISPERSION; OSCILLATOR; BREAKUP; PULSES
Web of Science 类别: Optics
研究方向: Optics
IDS 号: 007CE 
ISSN: 1094-4087 

第 55 条，共 210 条
标题: The resolution estimation of wedge and strip anodes 
作者: Yang, H (Yang, Hao); Zhao, BS (Zhao, Baosheng); Liu, YA (Liu, Yong'an); Yan, QR (Yan, Qiurong); Hu, HJ (Hu, Huijun)
来源出版物: REVIEW OF SCIENTIFIC INSTRUMENTS  卷: 83  期: 9  文献号: 093107  DOI: 10.1063/1.4729117  出版年: SEP 2012  
Web of Science 核心合集中的 "被引频次": 1 
被引频次合计: 1 
摘要: A new resolution estimation method for wedge and strip anode based on the single photon imaging configuration is provided. The limiting resolution estimation equation is deduced theoretically according to the threshold principle. The relation between the charge cloud and the covered electrodes is discussed, and the equivalent diameter number is calculated. The resolution equation for the position deviation amplitude or FWHM is provided if noise exists. The relation between the position deviation amplitude and the total charge deviation amplitudes is discussed. The constancy of the position deviation amplitudes versus positions is provided. The results calculated from these equations are discussed. According to the equations, it is indicated that the spatial resolution is affected by the detection system configuration and noise. These conclusions may be useful for the designing and performance improvement of future photon imagers. (C) 2012 American Institute of Physics. [http://dx.doi.org/10.1063/1.4729117]
PubMed ID: 23020362 
文献类型: Article
Web of Science 类别: Instruments & Instrumentation; Physics, Applied
研究方向: Instruments & Instrumentation; Physics
IDS 号: 015DW 
ISSN: 0034-6748 

第 56 条，共 210 条
标题: Spatial Frequency Multiplexing of Fiber-Optic Interferometric Refractive Index Sensors Based on Graded-Index Multimode Fibers 
作者: Liu, L (Liu, Li); Gong, Y (Gong, Yuan); Wu, Y (Wu, Yu); Zhao, T (Zhao, Tian); Wu, HJ (Wu, Hui-Juan); Rao, YJ (Rao, Yun-Jiang)
来源出版物: SENSORS  卷: 12  期: 9  页: 12377-12385  DOI: 10.3390/s120912377  出版年: SEP 2012  
Web of Science 核心合集中的 "被引频次": 2 
被引频次合计: 2 
摘要: Fiber-optic interferometric sensors based on graded-index multimode fibers have very high refractive-index sensitivity, as we previously demonstrated. In this paper, spatial-frequency multiplexing of this type of fiber-optic refractive index sensors is investigated. It is estimated that multiplexing of more than 10 such sensors is possible. In the multiplexing scheme, one of the sensors is used to investigate the refractive index and temperature responses. The fast Fourier transform (FFT) of the combined reflective spectra is analyzed. The intensity of the FFT spectra is linearly related with the refractive index and is not sensitive to the temperature.
文献类型: Article
作者关键词: fiber-optic sensors; graded-index multimode fiber (GI-MMF); Fabry-Perot sensor; refractive index sensor; spatial frequency multiplexing
KeyWords Plus: FABRY-PEROT SENSOR; TEMPERATURE SENSOR; OPTICAL-FIBER; INTERFERENCE; COMPACT
Web of Science 类别: Chemistry, Analytical; Electrochemistry; Instruments & Instrumentation
研究方向: Chemistry; Electrochemistry; Instruments & Instrumentation
IDS 号: 012XL 
ISSN: 1424-8220 

第 57 条，共 210 条
标题: Controllable cascaded four-wave mixing by two chirped femtosecond laser pulses 
作者: Zhang, H (Zhang, H.); Zhou, Z (Zhou, Z.); Lin, A (Lin, A.); Cheng, J (Cheng, J.); Liu, H (Liu, H.); Si, J (Si, J.); Chen, F (Chen, F.); Hou, X (Hou, X.)
来源出版物: APPLIED PHYSICS B-LASERS AND OPTICS  卷: 108  期: 3  页: 487-491  DOI: 10.1007/s00340-012-5038-1  出版年: SEP 2012  
Web of Science 核心合集中的 "被引频次": 0 
被引频次合计: 0 
摘要: We investigated the generation of cascaded four-wave mixing (CFWM) sidebands by using two crossing chirped femtosecond pulses with the same central wavelength in tellurite glass (Te glass). Sidebands of broadband spectra, which contained non-degenerate and degenerate CFWM signals, were obtained at different delay time between two input pulses. The CFWM sidebands observed on different sides of input beams were flexibly controlled by adjusting the delay time.
文献类型: Article
KeyWords Plus: GENERATION; GLASS; SPECTROSCOPY; MEDIA
Web of Science 类别: Optics; Physics, Applied
研究方向: Optics; Physics
IDS 号: 012CE 
ISSN: 0946-2171 

第 58 条，共 210 条
标题: Design of optical element combining Fresnel lens with microlens array for uniform light-emitting diode lighting 
作者: Wang, GZ (Wang, Guangzhen); Wang, LL (Wang, Lili); Li, FL (Li, Fuli); Kong, DP (Kong, Depeng)
来源出版物: JOURNAL OF THE OPTICAL SOCIETY OF AMERICA A-OPTICS IMAGE SCIENCE AND VISION  卷: 29  期: 9  页: 1877-1884  出版年: SEP 2012  
Web of Science 核心合集中的 "被引频次": 1 
被引频次合计: 1 
摘要: One kind of optical element combining Fresnel lens with microlens array is designed simply for LED lighting based on geometrical optics and nonimaging optics. This design method imposes no restriction on the source intensity pattern. The designed element has compact construction and can produce multiple shapes of illumination distribution. Taking square lighting as an example, tolerance analysis is carried out to determine tolerance limits for applying the element in the assembly process. This element can produce on-axis lighting and off-axis lighting. (C) 2012 Optical Society of America
PubMed ID: 23201944 
文献类型: Article
KeyWords Plus: ILLUMINATION; EXAMPLE
Web of Science 类别: Optics
研究方向: Optics
IDS 号: 009XX 
ISSN: 1084-7529 

第 59 条，共 210 条
标题: Autofocusing of digital holographic microscopy based on off-axis illuminations 
作者: Gao, P (Gao, Peng); Yao, BL (Yao, Baoli); Min, JW (Min, Junwei); Guo, RL (Guo, Rongli); Ma, BH (Ma, Baiheng); Zheng, JJ (Zheng, Juanjuan); Lei, M (Lei, Ming); Yan, SH (Yan, Shaohui); Dan, D (Dan, Dan); Ye, T (Ye, Tong)
来源出版物: OPTICS LETTERS  卷: 37  期: 17  页: 3630-3632  出版年: SEP 1 2012  
Web of Science 核心合集中的 "被引频次": 9 
被引频次合计: 9 
摘要: An auto-focusing method for digital holographic microscopy has been proposed by employing two off-axis illumination beams. When specimens are illuminated by two plane waves in different directions, it is found that the farther the reconstruction plane is from the image plane, the wider the two reconstructed images are separated from each other. Thus, the image plane can be determinated by finding the minimum of the variation between the two reconstructed object waves on both the amplitude and phase distributions. The feasibility of the proposed method is demonstrated by the corresponding simulation and experiment. (c) 2012 Optical Society of America
PubMed ID: 22940972 
文献类型: Article
KeyWords Plus: NUMERICAL RECONSTRUCTION; PHASE MICROSCOPY; INTERFEROMETRY; DIFFRACTION; OBJECTS; FIELD
Web of Science 类别: Optics
研究方向: Optics
IDS 号: 003GD 
ISSN: 0146-9592 

第 60 条，共 210 条
标题: An Improved Nyquist-Shannon Irregular Sampling Theorem From Local Averages 
作者: Song, ZJ (Song, Zhanjie); Liu, B (Liu, Bei); Pang, YW (Pang, Yanwei); Hou, CP (Hou, Chunping); Li, XL (Li, Xuelong)
来源出版物: IEEE TRANSACTIONS ON INFORMATION THEORY  卷: 58  期: 9  页: 6093-6100  DOI: 10.1109/TIT.2012.2199959  出版年: SEP 2012  
Web of Science 核心合集中的 "被引频次": 0 
被引频次合计: 0 
摘要: The Nyquist-Shannon sampling theorem is on the reconstruction of a band-limited signal from its uniformly sampled samples. The higher the signal bandwidth gets, the more challenging the uniform sampling may become. To deal with this problem, signal reconstruction from local averages has been studied in the literature. In this paper, we obtain an improved Nyquist-Shannon sampling theorem from general local averages. In practice, the measurement apparatus gives a weighted average over an asymmetrical interval. As a special case, for local averages from symmetrical interval, we show that the sampling rate is much lower than that of a result by Grochenig. Moreover, we obtain two exact dual frames from local averages, one of which improves a result by Sun and Zhou. At the end of this paper, as an example application of local average sampling, we consider a reconstruction algorithm: the piecewise linear approximations.
文献类型: Article
作者关键词: Band-limited signal; irregular sampling; sampling from local averages; signal reconstruction
KeyWords Plus: STOCHASTIC-PROCESSES; SIGNALS; RECONSTRUCTION; BEHAVIOR; SERIES; APPROXIMATION; EXTRAPOLATION; WAVELET; SPACES
Web of Science 类别: Computer Science, Information Systems; Engineering, Electrical & Electronic
研究方向: Computer Science; Engineering
IDS 号: 993XH 
ISSN: 0018-9448 

第 61 条，共 210 条
标题: The Correction of Recovered Spectral Images in a Hadamard Transform Spectral Imager Based on a Digital Micro-Mirror Device 
作者: Xu, J (Xu, Jun); Hu, BL (Hu, Bingliang); Feng, DZ (Feng, Dazheng)
来源出版物: APPLIED SPECTROSCOPY  卷: 66  期: 9  页: 1044-1052  DOI: 10.1366/11-06577  出版年: SEP 2012  
Web of Science 核心合集中的 "被引频次": 3 
被引频次合计: 4 
摘要: The Hadamard transform spectral imager based on a digital micro-mirror device (DMD) is a novel type of spectral imager developed in recent years. This paper describes the designing scheme of the Hadamard encoding mask and analyzes the encoding process of the detector pixels. Generally the Hadamard encoding mask constructed by DMD cannot completely encode the dispersed spectrum of all the pixels according to the Hadamard matrix; therefore, the spectral images recovered by inverse Hadamard transform inevitably have errors. A correction method for the recovered spectral images is proposed. The experimental results show that this method improves the quality of the recovered spectral images.
文献类型: Article
作者关键词: Hadamard transform; Digital micro-mirror device (DMD); Encoding mask; Spectral imager; Correction method
KeyWords Plus: PROGRAMMABLE ARRAY MICROSCOPE; FLUORESCENCE SPECTROSCOPY; PAM
Web of Science 类别: Instruments & Instrumentation; Spectroscopy
研究方向: Instruments & Instrumentation; Spectroscopy
IDS 号: 990AQ 
ISSN: 0003-7028 

第 62 条，共 210 条
标题: Vehicle detection and tracking in airborne videos by multi-motion layer analysis 
作者: Cao, XB (Cao, Xianbin); Lan, JH (Lan, Jinhe); Yan, PK (Yan, Pingkun); Li, XL (Li, Xuelong)
来源出版物: MACHINE VISION AND APPLICATIONS  卷: 23  期: 5  页: 921-935  DOI: 10.1007/s00138-011-0336-x  出版年: SEP 2012  
Web of Science 核心合集中的 "被引频次": 9 
被引频次合计: 9 
摘要: Airborne vehicle detection and tracking systems equipped on unmanned aerial vehicles (UAVs) are receiving more and more attention due to their advantages of high mobility, fast deployment and large surveillance scope. However, such systems are difficult to develop because of factors like UAV motion, scene complexity, and especially the partial occlusion of targets. To address these problems, a new framework of multi-motion layer analysis is proposed to detect and track moving vehicles in airborne platform. After motion layers are constructed, they are maintained over time for tracking vehicles. Most importantly, since the vehicle motion layers can be maintained even when the vehicles are only partially observed, the proposed method is robust to partial occlusion. Our experimental results showed that (1) compared with other previous algorithms, our method can achieve better performance in terms of higher detection rate and lower false positive rate; (2) it is more efficient and more robust to partial occlusion; (3) it is able to meet the demand of real time application due to its computational simplicity.
文献类型: Article
作者关键词: Vehicle detection; Frame registration; Feature tracking; Partial occlusion; Motion layer
KeyWords Plus: SURVEILLANCE; REGISTRATION; SEGMENTATION
Web of Science 类别: Computer Science, Artificial Intelligence; Computer Science, Cybernetics; Engineering, Electrical & Electronic
研究方向: Computer Science; Engineering
IDS 号: 989DB 
ISSN: 0932-8092 

第 63 条，共 210 条
标题: Image encryption algorithm based on the random local phase encoding in gyrator transform domains 
作者: Liu, ZJ (Liu, Zhengjun); Yang, M (Yang, Meng); Liu, W (Liu, Wei); Li, S (Li, She); Gong, M (Gong, Min); Liu, WY (Liu, Wanyu); Liu, ST (Liu, Shutian)
来源出版物: OPTICS COMMUNICATIONS  卷: 285  期: 19  页: 3921-3925  DOI: 10.1016/j.optcom.2012.05.061  出版年: SEP 1 2012  
Web of Science 核心合集中的 "被引频次": 11 
被引频次合计: 11 
摘要: A random local phase encoding method is presented for encrypting a secret image. Some random polygons are introduced to control the local regions of random phase encoding. The data located in the random polygon is encoded by random phase encoding. The random phase data is the main key in this encryption method. The different random phases calculated by using a monotonous function are employed. The random data defining random polygon serves as an additional key for enhancing the security of the image encryption scheme. Numerical simulations are given for demonstrating the performance of the proposed encryption approach. (C) 2012 Elsevier B.V. All rights reserved.
文献类型: Article
作者关键词: Random polygon; Gyrator transform; Random phase encoding
KeyWords Plus: FRACTIONAL FOURIER DOMAIN; OPTICAL ENCRYPTION; PLAINTEXT ATTACK; FRESNEL DOMAIN
Web of Science 类别: Optics
研究方向: Optics
IDS 号: 978XC 
ISSN: 0030-4018 

第 64 条，共 210 条
标题: Interactions of two humps of dipoles in anisotropic nonlinear media 
作者: Zhang, YQ (Zhang, Yiqi); Zhang, YP (Zhang, Yanpeng); Zhang, MZ (Zhang, Meizhi); Lu, KQ (Lu, Keqing)
来源出版物: OPTICS AND LASER TECHNOLOGY  卷: 44  期: 6  页: 1729-1732  DOI: 10.1016/j.optlastec.2012.01.028  出版年: SEP 2012  
Web of Science 核心合集中的 "被引频次": 2 
被引频次合计: 2 
摘要: Propagation of dipoles and superposed dipoles in anisotropic nonlinear medium is investigated. The two humps of the dipoles will repel each other if attraction between them is smaller than repulsion, while if the former is larger than the latter, they attract. If there is phase gradient on the input dipoles or the energy distribution of the dipoles does not along the boundary directions of the medium, the dipoles will exhibit incomplete rotation during propagation. (C) 2012 Elsevier Ltd. All rights reserved.
文献类型: Article
作者关键词: Dipole; Anisotropic; Beam propagation
KeyWords Plus: SELF-FOCUSING MEDIA; MODE VECTOR SOLITONS; PHOTOREFRACTIVE MEDIA; PHOTONIC LATTICES; DISCRETE SOLITONS; WAVE-GUIDES
Web of Science 类别: Optics; Physics, Applied
研究方向: Optics; Physics
IDS 号: 929SQ 
ISSN: 0030-3992 

第 65 条，共 210 条
标题: Snapshot imaging polarimeter using modified Savart polariscopes 
作者: Cao, QZ (Cao, Qizhi); Zhang, CM (Zhang, Chunmin); DeHoog, E (DeHoog, Edward)
来源出版物: APPLIED OPTICS  卷: 51  期: 24  页: 5791-5796  DOI: 10.1364/AO.51.005791  出版年: AUG 20 2012  
Web of Science 核心合集中的 "被引频次": 2 
被引频次合计: 2 
摘要: In this paper, based on the combination of two modified Savart polariscopes, we present a snapshot imaging polarimeter and show that the carrier frequency is two times higher than that of the snapshot imaging polarimeter using two conventional Savart polariscopes. The signal-to-noise ratio and the spatial resolution of imagery in each channel are improved due to the increase of the carrier frequency when we filter the channels to recover the Stokes vector images. Moreover, compared with conventional imaging polarimetry, the remarkable advantage of the proposed instrument is that it is also simple, compact, miniature, snapshotted, and static (no moving parts). To demonstrate the feasibility of the proposed snapshot imaging polarimeter, the numerical simulation of a design example is presented in detail. (c) 2012 Optical Society of America
PubMed ID: 22907005 
文献类型: Article
KeyWords Plus: POLARIZATION GRATINGS; COMPACT
Web of Science 类别: Optics
研究方向: Optics
IDS 号: 996HX 
ISSN: 1559-128X 
电子 ISSN: 2155-3165 

第 66 条，共 210 条
标题: Intense 2.7 mu m emission of Er3+-doped water-free fluorotellurite glasses 
作者: Zhan, H (Zhan, Huan); Zhou, ZG (Zhou, Zhiguang); He, JL (He, Jianli); Lin, AX (Lin, Aoxiang)
来源出版物: OPTICS LETTERS  卷: 37  期: 16  页: 3408-3410  出版年: AUG 15 2012  
Web of Science 核心合集中的 "被引频次": 13 
被引频次合计: 13 
摘要: By physical and chemical dehydration techniques, a group of Er3+-doped water-free fluorotellurite glasses with a composition of 60TeO(2)-30ZnF(2)-10NaF(TZNF60, mol%) + xEr(2)O(3)(wt%; x = 0 similar to 1.5) were fabricated. Under 978 nm excitation, the I-4(11/2) -> I-4(13/2) emission of Er3+ ions in TZNF60-glass was investigated: tau(f) is of 1.07 similar to 1.93 ms and emission bandwidth is about 163 nm at 2.71 mu m, which benefits from the absence of OH groups and the decreased phonon energy with the addition of fluorides. In contrast, 1.25Er-TZNF60 glass is proposed to be a promising material for mid-infrared fiber lasers at around 2.7 mu m. (c) 2012 Optical Society of America
PubMed ID: 23381273 
文献类型: Article
KeyWords Plus: SPECTROSCOPIC PROPERTIES; TELLURITE GLASSES; FLUORIDE GLASS; FIBER LASER; DIODE; ER3+; IONS
Web of Science 类别: Optics
研究方向: Optics
IDS 号: 994TY 
ISSN: 0146-9592 

第 67 条，共 210 条
标题: Optimizing initial chirp for efficient femtosecond wavelength conversion in silicon waveguide by split-step Fourier method 
作者: Li, XF (Li, Xuefeng); Wang, ZL (Wang, Zhaolu); Liu, HJ (Liu, Hongjun)
来源出版物: APPLIED MATHEMATICS AND COMPUTATION  卷: 218  期: 24  页: 11970-11975  DOI: 10.1016/j.amc.2012.05.065  出版年: AUG 15 2012  
Web of Science 核心合集中的 "被引频次": 1 
被引频次合计: 1 
摘要: Based on solving numerically the generalized nonlinear Schrodinger (GNLS) equation by a split-step Fourier method, efficient femtosecond wavelength conversion in the telecommunication bands via four-wave mixing in silicon rib waveguide is numerically investigated by optimizing the initial chirp of the pump and signal pulses. It is shown that the relative narrower four-wave mixing spectra with the most of the energy remains in the central peak can be obtained by the use of appropriate negative chirp, and the conversion bandwidth greater than 500 nm and peak conversion efficiency of -1.6 dB can be obtained by using 200 fs pulses with a repetition rate of 40 GHz in a 3.2-mm-long silicon rib waveguide. (C) 2012 Elsevier Inc. All rights reserved.
文献类型: Article
作者关键词: Wavelength conversion; Ultrafast laser; Nonlinear Schrodinger equation; Split-step Fourier method; Optimization
KeyWords Plus: NONLINEAR SCHRODINGER-EQUATION; SELF-PHASE MODULATION; GAIN
Web of Science 类别: Mathematics, Applied
研究方向: Mathematics
IDS 号: 973KQ 
ISSN: 0096-3003 

第 68 条，共 210 条
标题: All-fiber normal-dispersion single-polarization passively mode-locked laser based on a 45 degrees-tilted fiber grating 
作者: Liu, XL (Liu, Xianglian); Wang, HS (Wang, Hushan); Yan, ZJ (Yan, Zhijun); Wang, YS (Wang, Yishan); Zhao, W (Zhao, Wei); Zhang, W (Zhang, Wei); Zhang, L (Zhang, Lin); Yang, Z (Yang, Zhi); Hu, XH (Hu, Xiaohong); Li, XH (Li, Xiaohui); Shen, DY (Shen, Deyuan); Li, C (Li, Cheng); Chen, GD (Chen, Guangde)
来源出版物: OPTICS EXPRESS  卷: 20  期: 17  页: 19000-19005  DOI: 10.1364/OE.20.019000  出版年: AUG 13 2012  
Web of Science 核心合集中的 "被引频次": 5 
被引频次合计: 5 
摘要: An all-fiber normal-dispersion Yb-doped fiber laser with 45 degrees-tilted fiber grating (TFG) is, to the best of our knowledge, experimentally demonstrated for the first time. Stable linearly-chirped pulses with the duration of 4 ps and the bandwidth of 9 nm can be directly generated from the laser cavity. By employing the 45 degrees TFG with the polarization-dependent loss of 33 dB, output pulses with high polarization extinction ratio of 26 dB are implemented in the experiment. Our result shows that the 45 degrees TFG can work effectively as a polarizer, which could be exploited to single-polarization all-fiber lasers. (C) 2012 Optical Society of America
PubMed ID: 23038540 
文献类型: Article
KeyWords Plus: DISSIPATIVE SOLITONS; RING LASER; GENERATION; PULSES; OSCILLATOR; POWER
Web of Science 类别: Optics
研究方向: Optics
IDS 号: 993QC 
ISSN: 1094-4087 

第 69 条，共 210 条
标题: All-Fiber Dissipative Solitons Evolution in a Compact Passively Yb-Doped Mode-Locked Fiber Laser 
作者: Li, XH (Li, Xiaohui); Wang, YS (Wang, Yishan); Zhao, W (Zhao, Wei); Liu, XL (Liu, Xianglian); Wang, YG (Wang, Yonggang); Tsang, YH (Tsang, Yuen Hong); Zhang, W (Zhang, Wei); Hu, XH (Hu, Xiaohong); Yang, Z (Yang, Zhi); Gao, CX (Gao, Cunxiao); Li, C (Li, Cheng); Shen, DY (Shen, Deyuan)
来源出版物: JOURNAL OF LIGHTWAVE TECHNOLOGY  卷: 30  期: 15  页: 2502-2507  DOI: 10.1109/JLT.2012.2201210  出版年: AUG 1 2012  
Web of Science 核心合集中的 "被引频次": 6 
被引频次合计: 6 
摘要: Compact all-fiber all-normal dispersion Yb-doped fiber ring laser is demonstrated based on nonlinear polarization rotation technique. Dissipative solitons (DSs) with bell-shaped spectra are observed in the fiber cavity with linear chirps for the first time to our knowledge. Stable pulse width is 9.7 ps with the pulse energy of 1.2 nJ, which can be compressed to near the transformed limited pulse duration of 225 fs. The experimental result agrees well with the numerical simulations. The theoretical modeling indicates that the formation of the bell-shaped spectra is due to the combined effect of normal dispersion, nonlinearity, gain, loss, and spectral filtering effect. Different from the pulse evolution in the mode-locked fiber laser based on the wave plate and the birefringent plate, conventional DSs with rectangular-shaped spectra can be obtained by varying the polarization orientation of the cavity.
文献类型: Article
作者关键词: All-normal dispersion; bell-shaped spectra; compression; mode-locked fiber lasers
KeyWords Plus: HIGH-ENERGY PULSES; NORMAL-DISPERSION; REPETITION RATE; RING LASER; GENERATION; FILTER; COMPENSATION
Web of Science 类别: Engineering, Electrical & Electronic; Optics; Telecommunications
研究方向: Engineering; Optics; Telecommunications
IDS 号: 085AT 
ISSN: 0733-8724 

第 70 条，共 210 条
标题: Route of delivering 40-fs ultra-short laser pulses for gating photoconductive antenna in fiber-coupled terahertz time-domain spectroscopy 
作者: Liu, J (Liu, Jia); Fan, WH (Fan, Wen-Hui); Chen, LC (Chen, Long-Chao)
来源出版物: OPTICAL ENGINEERING  卷: 51  期: 8  文献号: 085001  DOI: 10.1117/1.OE.51.8.085001  出版年: AUG 2012  
Web of Science 核心合集中的 "被引频次": 0 
被引频次合计: 0 
摘要: A route of delivering ultra-short laser pulses through a polarization-maintaining single-mode fiber has been investigated experimentally. The group velocity dispersion was well compensated, and the self-phase modulation was depressed in fiber. Finally, a 40-fs laser pulse with the energy of 70 pJ was obtained at the output of the transmitted fiber with the length up to 4 m in our fiber-delivery system. The route exhibits distinguishing features of compactness and flexibility, and this 40-fs laser pulse can be used not only to generate broadband terahertz (THz) radiation but also to detect broadband THz radiation, which is much better than the 150-fs laser pulse used previously. (C) 2012 Society of Photo-Optical Instrumentation Engineers (SPIE). [DOI: 10.1117/1.OE.51.8.085001]
文献类型: Article
作者关键词: terahertz time-domain spectroscopy; group velocity dispersion; third-order dispersion; self-phase modulation; photoconductive antenna
KeyWords Plus: DISPERSION COMPENSATION; COMPRESSION; EXPLOSIVES; COMPACT; SYSTEM; DRUGS
Web of Science 类别: Optics
研究方向: Optics
IDS 号: 021VH 
ISSN: 0091-3286 

第 71 条，共 210 条
标题: Analysis of field of view limited by a multi-line X-ray source and its improvement for grating interferometry 
作者: Du, Y (Du, Yang); Huang, JH (Huang, Jianheng); Lin, DY (Lin, Danying); Niu, HB (Niu, Hanben)
来源出版物: ANALYTICAL AND BIOANALYTICAL CHEMISTRY  卷: 404  期: 3  页: 793-797  DOI: 10.1007/s00216-012-6178-1  出版年: AUG 2012  
Web of Science 核心合集中的 "被引频次": 1 
被引频次合计: 1 
摘要: X-ray phase-contrast imaging based on grating interferometry is a technique with the potential to provide absorption, differential phase contrast, and dark-field signals simultaneously. The multi-line X-ray source used recently in grating interferometry has the advantage of high-energy X-rays for imaging of thick samples for most clinical and industrial investigations. However, it has a drawback of limited field of view (FOV), because of the axial extension of the X-ray emission area. In this paper, we analyze the effects of axial extension of the multi-line X-ray source on the FOV and its improvement in terms of Fresnel diffraction theory. Computer simulation results show that the FOV limitation can be overcome by use of an alternative X-ray tube with a specially designed multi-step anode. The FOV of this newly designed X-ray source can be approximately four times larger than that of the multi-line X-ray source in the same emission area. This might be beneficial for the applications of X-ray phase contrast imaging in materials science, biology, medicine, and industry.
PubMed ID: 22729354 
文献类型: Article
作者关键词: X-ray phase contrast imaging; Grating interferometry; Multi-line X-ray source; Field of view
KeyWords Plus: COMPUTED-TOMOGRAPHY; FABRICATION
Web of Science 类别: Biochemical Research Methods; Chemistry, Analytical
研究方向: Biochemistry & Molecular Biology; Chemistry
IDS 号: 985GR 
ISSN: 1618-2642 

第 72 条，共 210 条
标题: Face Sketch-Photo Synthesis and Retrieval Using Sparse Representation 
作者: Gao, XB (Gao, Xinbo); Wang, NN (Wang, Nannan); Tao, DC (Tao, Dacheng); Li, XL (Li, Xuelong)
来源出版物: IEEE TRANSACTIONS ON CIRCUITS AND SYSTEMS FOR VIDEO TECHNOLOGY  卷: 22  期: 8  页: 1213-1226  DOI: 10.1109/TCSVT.2012.2198090  出版年: AUG 2012  
Web of Science 核心合集中的 "被引频次": 10 
被引频次合计: 11 
摘要: Sketch-photo synthesis plays an important role in sketch-based face photo retrieval and photo-based face sketch retrieval systems. In this paper, we propose an automatic sketch-photo synthesis and retrieval algorithm based on sparse representation. The proposed sketch-photo synthesis method works at patch level and is composed of two steps: sparse neighbor selection (SNS) for an initial estimate of the pseudoimage (pseudosketch or pseudophoto) and sparse-representation-based enhancement (SRE) for further improving the quality of the synthesized image. SNS can find closely related neighbors adaptively and then generate an initial estimate for the pseudoimage. In SRE, a coupled sparse representation model is first constructed to learn the mapping between sketch patches and photo patches, and a patch-derivative-based sparse representation method is subsequently applied to enhance the quality of the synthesized photos and sketches. Finally, four retrieval modes, namely, sketch-based, photo-based, pseudosketch-based, and pseudophoto-based retrieval are proposed, and a retrieval algorithm is developed by using sparse representation. Extensive experimental results illustrate the effectiveness of the proposed face sketch-photo synthesis and retrieval algorithms.
文献类型: Article
作者关键词: Face sketch-photo synthesis; sketch-photo-based retrieval; sparse neighbor selection; sparse representation
KeyWords Plus: RECOGNITION ALGORITHMS; SELECTIVE ENSEMBLE; E-HMM; IMAGE
Web of Science 类别: Engineering, Electrical & Electronic
研究方向: Engineering
IDS 号: 001CN 
ISSN: 1051-8215 

第 73 条，共 210 条
标题: Stressed waveguides with tubular depressed-cladding inscribed in phosphate glasses by femtosecond hollow laser beams 
作者: Long, XW (Long, Xuewen); Bai, J (Bai, Jing); Zhao, W (Zhao, Wei); Stoian, R (Stoian, Razvan); Hui, RQ (Hui, Rongqing); Cheng, GH (Cheng, Guanghua)
来源出版物: OPTICS LETTERS  卷: 37  期: 15  页: 3138-3140  出版年: AUG 1 2012  
Web of Science 核心合集中的 "被引频次": 2 
被引频次合计: 2 
摘要: We report on the single-step fabrication of stressed optical waveguides with tubular depressed-refractive-index cladding in phosphate glasses by the use of focused femtosecond hollow laser beams. Tubelike low index regions appear under direct exposure due to material rarefaction following expansion. Strained compacted zones emerged in domains neighboring the tubular track of lower refractive index, and waveguiding occurs mainly within the tube core fabricated by the engineered femtosecond laser beam. The refractive index profile of the optical waveguide was reconstructed from the measured transmitted near-field intensity. (C) 2012 Optical Society of America
PubMed ID: 22859111 
文献类型: Article
KeyWords Plus: WRITTEN; FABRICATION; PULSES
Web of Science 类别: Optics
研究方向: Optics
IDS 号: 984XM 
ISSN: 0146-9592 

第 74 条，共 210 条
标题: Two-Dimensional Optical Lattice Solitons in Photovoltaic-Photorefractive Crystals 
作者: Guo, JB (Guo Jian-Bang); Lu, KQ (Lu Ke-Qing); Niu, PJ (Niu Ping-Juan); Yu, LY (Yu Li-Yuan); Xing, HY (Xing Hai-Ying)
来源出版物: CHINESE PHYSICS LETTERS  卷: 29  期: 8  文献号: 084212  DOI: 10.1088/0256-307X/29/8/084212  出版年: AUG 2012  
Web of Science 核心合集中的 "被引频次": 0 
被引频次合计: 0 
摘要: We study two families of two-dimensional bright lattice solitons in photovoltaic-photorefractive crystals. It is shown that self-focusing and self-defocusing lattice solitons are possible only when their power level exceeds a critical threshold. It is found that self-focusing lattice solitons exist not only in the semi-infinite band gap, but also in the first band gap, whereas self-defocusing lattice solitons exist only in the first band gap. The structures of these lattice solitons are also analyzed. Our results indicate that a self-focusing lattice soliton in the semi-infinite band gap is more confined than in the first band gap so its tails in the first band gap occupy many lattice sites; when a self-defocusing lattice soliton is close to the second band, the self-defocusing lattice soliton is more confined so its tails occupy a few lattice sites.
文献类型: Article
KeyWords Plus: NONLINEAR PHOTONIC LATTICES; DISCRETE SOLITONS; GAP SOLITONS
Web of Science 类别: Physics, Multidisciplinary
研究方向: Physics
IDS 号: 990YE 
ISSN: 0256-307X 

第 75 条，共 210 条
标题: High efficiency terahertz-wave photonic crystal fiber optical parametric oscillator 
作者: Li, SP (Li, Shaopeng); Liu, HJ (Liu, Hongjun); Huang, N (Huang, Nan); Sun, QB (Sun, Qibing); Li, XF (Li, Xuefeng)
来源出版物: APPLIED OPTICS  卷: 51  期: 22  页: 5579-5584  DOI: 10.1364/AO.51.005579  出版年: AUG 1 2012  
Web of Science 核心合集中的 "被引频次": 0 
被引频次合计: 0 
摘要: We theoretically propose phase matched terahertz (THz)-wave generation via degenerate four-wave mixing (FWM) in a fiber optical parametric oscillator (FOPO) with our newly designed photonic crystal fiber (PCF). Perfect phase matching is realized when we locate the pump wavelength in the normal group-velocity dispersion (GVD) regime. The generated THz-wave can be tuned from 4.7578 to 5.9015 THz by varying the pump wavelength. Moreover, peak power of 27.38 W at 5.9015 THz with conversion efficiency of 1.37% is realized when the pump peak power of 2000 W is at 4.675 mu m in our FOPO. (C) 2012 Optical Society of America
PubMed ID: 22859051 
文献类型: Article
KeyWords Plus: GENERATION; SILICON; CONVERSION; CANCER
Web of Science 类别: Optics
研究方向: Optics
IDS 号: 984AU 
ISSN: 1559-128X 
电子 ISSN: 2155-3165 

第 76 条，共 210 条
标题: Modulation instability of bright photovoltaic solitons on a partially incoherent background 
作者: Zhang, M (Zhang, M.); Huo, G (Huo, G.); Zhang, Y (Zhang, Y.); Kang, Y (Kang, Y.); Duan, Z (Duan, Z.)
来源出版物: LASER PHYSICS  卷: 22  期: 8  页: 1295-1300  DOI: 10.1134/S1054660X12080178  出版年: AUG 2012  
Web of Science 核心合集中的 "被引频次": 0 
被引频次合计: 0 
摘要: We present the observation of incoherent anti-dark photovoltaic solitons in LiNbO3:Fe crystal. This new class of soliton states involves bright photovoltaic solitons on a background beam meeting kappa > 1, where kappa is the ratio of background illumination photovoltaic constant to that of soliton beam. For kappa < 1, dark photovoltaic solitons are generated. Furthermore, this novel type solitons are investigated experimentally by injecting coherent light and partially coherent background of infinite extent. In case of spatial coherence of the background lower than the threshold of incoherent modulation instability, these results indicate that bright photovoltaic solitons can propagate in a stable fashion.
文献类型: Article
KeyWords Plus: SPATIAL SOLITONS; SCREENING SOLITONS; DARK; LIGHT; DISPERSION; CRYSTAL; BEAMS; FIELD
Web of Science 类别: Optics; Physics, Applied
研究方向: Optics; Physics
IDS 号: 986AJ 
ISSN: 1054-660X 

第 77 条，共 210 条
标题: Design and Implementation of Real-Time Processing Platform for Movement Error Correction of Hyperspectrual Imaging 
作者: Yu, T (Yu Tao); Hu, BL (Hu Bing-liang); Gao, XH (Gao Xiao-hui); Wei, RY (Wei Ru-yi); Jing, JJ (Jing Juan-juan)
来源出版物: SPECTROSCOPY AND SPECTRAL ANALYSIS  卷: 32  期: 8  页: 2275-2279  DOI: 10.3964/j.issn.1000-0593(2012)08-2275-05  出版年: AUG 2012  
Web of Science 核心合集中的 "被引频次": 0 
被引频次合计: 0 
摘要: The approach that deals with compressed and packed image data transmitted from satellite to the ground is too slow for real-time application occasion, it also has huge image, multi-processing step and complexity recovery arithmetic synchronously, so it is urgent to build accurate and fast data processing platform for real-time processing. For the moment, the platform for data recovery and error correction is much less, the so-called successful platform may directly affect the effect of target detection and identification because of processing speed, precision, flexibility, configuration and upgrade. The platform we build is to set spatial modulation spectrometer as the research goal, We design and implement a hardware platform based on Xilinx Virtex-5 FPGA, It is combined with ISE IP soft-core resources which is configurable, high-precision and flexible by focusing on analyzing key aspects of the hardware platform. And the relevant test data were drawn, then a good way for spectrum recovery and error correction was explored.
文献类型: Article
作者关键词: Xilinx; IPcore; Handware platforms; Error correction
KeyWords Plus: SPECTROMETER
Web of Science 类别: Spectroscopy
研究方向: Spectroscopy
IDS 号: 983NW 
ISSN: 1000-0593 

第 78 条，共 210 条
标题: Robust Reversible Watermarking via Clustering and Enhanced Pixel-Wise Masking 
作者: An, LL (An, Lingling); Gao, XB (Gao, Xinbo); Li, XL (Li, Xuelong); Tao, DC (Tao, Dacheng); Deng, C (Deng, Cheng); Li, J (Li, Jie)
来源出版物: IEEE TRANSACTIONS ON IMAGE PROCESSING  卷: 21  期: 8  页: 3598-3611  DOI: 10.1109/TIP.2012.2191564  出版年: AUG 2012  
Web of Science 核心合集中的 "被引频次": 14 
被引频次合计: 14 
摘要: Robust reversible watermarking (RRW) methods are popular in multimedia for protecting copyright, while preserving intactness of host images and providing robustness against unintentional attacks. However, conventional RRW methods are not readily applicable in practice. That is mainly because: 1) they fail to offer satisfactory reversibility on large-scale image datasets; 2) they have limited robustness in extracting watermarks from the watermarked images destroyed by different unintentional attacks; and 3) some of them suffer from extremely poor invisibility for watermarked images. Therefore, it is necessary to have a framework to address these three problems, and further improve its performance. This paper presents a novel pragmatic framework, wavelet-domain statistical quantity histogram shifting and clustering (WSQH-SC). Compared with conventional methods, WSQH-SC ingeniously constructs new watermark embedding and extraction procedures by histogram shifting and clustering, which are important for improving robustness and reducing run-time complexity. Additionally, WSQH-SC includes the property-inspired pixel adjustment to effectively handle overflow and underflow of pixels. This results in satisfactory reversibility and invisibility. Furthermore, to increase its practical applicability, WSQH-SC designs an enhanced pixel-wise masking to balance robustness and invisibility. We perform extensive experiments over natural, medical, and synthetic aperture radar images to show the effectiveness of WSQH-SC by comparing with the histogram rotation-based and histogram distribution constrained methods.
PubMed ID: 22453636 
文献类型: Article
作者关键词: Integer wavelet transform; k-means clustering; masking; robust reversible watermarking (RRW)
KeyWords Plus: STATISTICAL QUANTITY HISTOGRAM; DIGITAL WATERMARKING; IMAGE WATERMARKING; AUTHENTICATION; DIFFERENCE; MODEL
Web of Science 类别: Computer Science, Artificial Intelligence; Engineering, Electrical & Electronic
研究方向: Computer Science; Engineering
IDS 号: 976PZ 
ISSN: 1057-7149 
电子 ISSN: 1941-0042 

第 79 条，共 210 条
标题: Free-space propagation of guided optical vortices excited in an annular core fiber 
作者: Yan, HW (Yan, Hongwei); Zhang, ET (Zhang, Entao); Zhao, BY (Zhao, Baoyin); Duan, KL (Duan, Kailiang)
来源出版物: OPTICS EXPRESS  卷: 20  期: 16  页: 17904-17915  DOI: 10.1364/OE.20.017904  出版年: JUL 30 2012  
Web of Science 核心合集中的 "被引频次": 1 
被引频次合计: 2 
摘要: The analytical expression for the propagation of guided optical vortices through free space is derived and used to study the dynamic evolution of guided optical vortices after passing through the free space, and the dependence of guided optical vortices on the control parameters where the effect of propagation distance is stressed. It is shown that the motion, pair creation and annihilation of guided optical vortices may take place. In particular, the creation and annihilation of a pair of guided optical vortices do not take place by varying fiber length. (c) 2012 Optical Society of America
PubMed ID: 23038340 
文献类型: Article
KeyWords Plus: FEW-MODE FIBER; FIELD DISLOCATIONS; WAVE-GUIDE; SINGULAR OPTICS; CROSS-SECTION; DISCLINATIONS; DYNAMICS; VORTEX; GENERATION
Web of Science 类别: Optics
研究方向: Optics
IDS 号: 986PR 
ISSN: 1094-4087 

第 80 条，共 210 条
标题: Incremental threshold learning for classifier selection 
作者: Pang, YW (Pang, Yanwei); Deng, JP (Deng, Junping); Yuan, Y (Yuan, Yuan)
来源出版物: NEUROCOMPUTING  卷: 89  页: 89-95  DOI: 10.1016/j.neucom.2012.01.012  出版年: JUL 15 2012  
Web of Science 核心合集中的 "被引频次": 3 
被引频次合计: 4 
摘要: Threshold-based classifier is a simple yet powerful pattern classification tool, which has been frequently used in applications of object detection and recognition. A threshold-based classifier is usually associated with a unique one-dimensional feature. A properly selected threshold and a binary sign corresponding to the feature govern the classifier. However, the learning process is usually done in a batch manner. The batch algorithms are not suitable for sequentially incoming data because of the limitation of storage and prohibitive computation cost. To deal with sequentially incoming data, this paper proposes an incremental algorithm for incrementally learning the threshold-based classifiers. The proposed method can not only incrementally model the features but also estimate the threshold and training error in a close form. The effectiveness of the proposed algorithm is evaluated in the applications of gender recognition, face detection, and human detection. (c) 2012 Elsevier B.V. All rights reserved.
文献类型: Article
作者关键词: Incremental learning; Threshold-based classifier; Classifier fusion; Object detection; Pattern recognition
KeyWords Plus: LOCAL BINARY PATTERNS; FACE-RECOGNITION; NEURAL-NETWORK; PROPAGATION; SCALE
Web of Science 类别: Computer Science, Artificial Intelligence
研究方向: Computer Science
IDS 号: 950GV 
ISSN: 0925-2312 

第 81 条，共 210 条
标题: Single-shot parallel four-step phase shifting using on-axis Fizeau interferometry 
作者: Abdelsalam, DG (Abdelsalam, D. G.); Yao, BL (Yao, Baoli); Gao, P (Gao, Peng); Min, JW (Min, Junwei); Guo, RL (Guo, Rongli)
来源出版物: APPLIED OPTICS  卷: 51  期: 20  页: 4891-4895  DOI: 10.1364/AO.51.004891  出版年: JUL 10 2012  
Web of Science 核心合集中的 "被引频次": 6 
被引频次合计: 7 
摘要: The purposes of the paper are threefold: (1) to show the possibility to perform parallel phase-shifting Fizeau interferometry by using a quarter waveplate with high flatness as a reference, (2) to present a comparative study between the phase-shifting algorithm and the off-axis geometry in surface micro-topography measurement, and (3) to show the advantages of using the proposed common path Fizeau interferometry over the quasi-common path Michelson interferometry in terms of accuracy in measurement. The compelling advantage of the proposed parallel phase-shifting Fizeau interferometric technique is the long-term stability that leads to measuring objects with a high degree of accuracy. (C) 2012 Optical Society of America
PubMed ID: 22781270 
文献类型: Article
KeyWords Plus: DIGITAL HOLOGRAPHY; POLARIZING SEPARATION; PAIR
Web of Science 类别: Optics
研究方向: Optics
IDS 号: 972QB 
ISSN: 1559-128X 
电子 ISSN: 2155-3165 

第 82 条，共 210 条
标题: Trapping of surface plasmon waves in graded grating waveguide system 
作者: Wang, GX (Wang, Guoxi); Lu, H (Lu, Hua); Liu, XM (Liu, Xueming)
来源出版物: APPLIED PHYSICS LETTERS  卷: 101  期: 1  文献号: 013111  DOI: 10.1063/1.4733477  出版年: JUL 2 2012  
Web of Science 核心合集中的 "被引频次": 35 
被引频次合计: 35 
摘要: We have proposed a graded grating plasmonic system with a significant slow-light effect for the propagation of high-confinement surface plasmon (SP) wave. Theoretical analysis and numerical simulations show that the localized position of SP wave in the plasmonic waveguide is dependent on the operating frequency. It is found that the slow-light effect exhibits an obvious enhancement with propagation. The proposed ultracompact configuration offers the advantage of a large trapping bandwidth of 90 THz, which may find excellent applications on slow-light systems, especially optical buffers. (C) 2012 American Institute of Physics. [http://dx.doi.org/10.1063/1.4733477]
文献类型: Article
作者关键词: diffraction gratings; numerical analysis; optical waveguides; plasmonics; surface plasmons
KeyWords Plus: BRAGG GRATINGS; STUB STRUCTURE; SLOW-LIGHT
Web of Science 类别: Physics, Applied
研究方向: Physics
IDS 号: 970PM 
ISSN: 0003-6951 
电子 ISSN: 1077-3118 

第 83 条，共 210 条
标题: Polarization behavior of femtosecond laser written optical waveguides in Ti:Sapphire 
作者: Bai, J (Bai, Jing); Cheng, GH (Cheng, Guanghua); Long, XW (Long, Xuewen); Wang, YS (Wang, Yishan); Zhao, W (Zhao, Wei); Chen, GF (Chen, Guofu); Stoian, R (Stoian, Razvan); Hui, RQ (Hui, Rongqing)
来源出版物: OPTICS EXPRESS  卷: 20  期: 14  页: 15035-15044  DOI: 10.1364/OE.20.015035  出版年: JUL 2 2012  
Web of Science 核心合集中的 "被引频次": 4 
被引频次合计: 4 
摘要: Ultrashort pulsed laser photoinscription of Ti:Sapphire crystals may result in the self-organization of nanoscale material redistribution regions in regular patterns within the laser trace and stress-induced birefringence around the laser trace. We report on the formation of anisotropic optical waveguides in Ti:Sapphire by a procedure that involves femtosecond laser inscription of adjacent nonguiding birefringent traces with nanopatterned crosssections and the accumulation of stress birefringence in the region between. Double parallel line structures with a separation of 25 mu m with vertical and horizontal nanoscale arrangements were written with a choice of orthogonal polarizations. Due to anisotropic light scattering on periodic nanostructures and stress-induced birefringence in the central zone, remarkable polarization dependent guiding effects were observed as a function of the microscopic geometry of the structures. Building on this polarization sensitivity, several structure such as 3 x 3 waveguide arrays, diamond and hexagon patterns are also investigated. (c) 2012 Optical Society of America
PubMed ID: 22772199 
文献类型: Article
KeyWords Plus: SILICA GLASS; FUSED-SILICA; SAPPHIRE; IRRADIATION; PULSES; LINBO3
Web of Science 类别: Optics
研究方向: Optics
IDS 号: 971BF 
ISSN: 1094-4087 

第 84 条，共 210 条
标题: Ultrabroadband flat dispersion tailoring of dual-slot silicon waveguides 
作者: Zhu, M (Zhu, Ming); Liu, HJ (Liu, Hongjun); Li, XF (Li, Xuefeng); Huang, N (Huang, Nan); Sun, QB (Sun, Qibing); Wen, J (Wen, Jin); Wang, ZL (Wang, Zhaolu)
来源出版物: OPTICS EXPRESS  卷: 20  期: 14  页: 15899-15907  DOI: 10.1364/OE.20.015899  出版年: JUL 2 2012  
Web of Science 核心合集中的 "被引频次": 15 
被引频次合计: 15 
摘要: We propose a new strip/slot hybrid waveguide with double slots, which exhibits a flat and low dispersion over a 1098-nm bandwidth with four zero-dispersion wavelengths. Dispersion of dual-slot silicon waveguide is mainly determined by mode transition from a strip mode to a slot mode rather than by material dispersion. Dispersion tailoring is investigated by tuning different structural parameters of waveguides. Moreover, nonlinear coefficient of dual-slot silicon waveguide and phase-matching condition in FWM are both explored in detail. The dual-slot waveguide can be used to generate supercontinuum with bandwidth extending up to 1630 nm pumped by femtosecond pulses. This waveguide will have a great potential for ultrabroadband signal processing applications from near-infrared region to mid-infrared region. (C) 2012 Optical Society of America
PubMed ID: 22772280 
文献类型: Article
KeyWords Plus: BAND WAVELENGTH CONVERSION; SELF-PHASE MODULATION; SUPERCONTINUUM GENERATION; 2-PHOTON ABSORPTION; NANOPHOTONIC WIRES; BIREFRINGENCE; AMPLIFICATION; OCTAVE; IMPACT; SI
Web of Science 类别: Optics
研究方向: Optics
IDS 号: 971BF 
ISSN: 1094-4087 

第 85 条，共 210 条
标题: Phase contrast microscopy with fringe contrast adjustable by using grating-based phase-shifter 
作者: Zheng, JJ (Zheng, Juanjuan); Yao, BL (Yao, Baoli); Gao, P (Gao, Peng); Ye, T (Ye, Tong)
来源出版物: OPTICS EXPRESS  卷: 20  期: 14  页: 16077-16082  DOI: 10.1364/OE.20.016077  出版年: JUL 2 2012  
Web of Science 核心合集中的 "被引频次": 0 
被引频次合计: 0 
摘要: In this paper a new phase contrast method with fringe contrast adjustable is proposed. In the Fourier plane of the object wave, two Ronchi gratings i.e., a central grating and a surrounding grating, are used to modulate the phases of the undiffracted and diffracted components, respectively. By loading the two gratings separately on spatial light modulator, the undiffracted and diffracted components can be measured independently, which simplify greatly the reconstruction process. Besides, the fringe contrast of the phase contrast interferogram can be adjusted by changing the modulation depth of the two gratings. The feasibility of the proposed method is verified by theoretical analysis and experiment. (C) 2012 Optical Society of America
PubMed ID: 22772298 
文献类型: Article
KeyWords Plus: COMMON-PATH INTERFEROMETRY; DIFFRACTION PHASE; DYNAMICS; LIGHT
Web of Science 类别: Optics
研究方向: Optics
IDS 号: 971BF 
ISSN: 1094-4087 

第 86 条，共 210 条
标题: Vector solitons with polarization instability and locked polarization in a fiber laser 
作者: Tang, DK (Tang, Dingkang); Zhang, JG (Zhang, Jian-Guo); Liu, YS (Liu, Yuanshan)
来源出版物: OPTICAL ENGINEERING  卷: 51  期: 7  文献号: 074202  DOI: 10.1117/1.OE.51.7.074202  出版年: JUL 2012  
Web of Science 核心合集中的 "被引频次": 0 
被引频次合计: 0 
摘要: We investigate the characteristics of vector solitons with and without locked phase velocities of orthogonal polarization components in a specially-designed laser cavity which is formed by a bidirectional fiber loop together with a semiconductor saturable absorber mirror. The characteristics of the two states are compared in the temporal and spectrum domain, respectively. Both of the two states exhibit the characteristic of mode locking while the two orthogonal polarization components are not resolved. However, for the vector soliton with unlocked phase velocities, identical intensity varies after passing through a polarization beam splitter (PBS) outside the laser cavity. Contrary to the polarization rotation locked vector soliton, the intensity does not change periodically. For the polarization-locked vector soliton (PLVS), the identical pulse intensity is still obtained after passing through the PBS and can be observed on the oscilloscope screen after photodetection. A coupler instead of a circulator is integrated in the laser cavity and strong interaction on the polarization resolved spectra of the PLVS is observed. By comparing the two states, we conclude that interaction between the two orthogonal components contributes to the locked phase velocities. (C) 2012 Society of Photo-Optical Instrumentation Engineers (SPIE). [DOI: 10.1117/1.OE.51.7.074202]
文献类型: Article
作者关键词: fiber lasers; mode locking; solitons in optical fibers
KeyWords Plus: BIREFRINGENT OPTICAL FIBERS; MODE-LOCKING; DISPERSION
Web of Science 类别: Optics
研究方向: Optics
IDS 号: 000BJ 
ISSN: 0091-3286 

第 87 条，共 210 条
标题: Improvement of Interfacial Adhesion Strength and Thermal Stability of Cu/p-SiC:H/SiOC:H Film Stack by Plasma Treatment on the Surface of Cu Film 
作者: Liu, B (Liu Bo); Yang, JJ (Yang Jijun); Jiao, GH (Jiao Guohua); Hu, KW (Hu Kewei)
来源出版物: PLASMA SCIENCE & TECHNOLOGY  卷: 14  期: 7  页: 619-623  DOI: 10.1088/1009-0630/14/7/12  出版年: JUL 2012  
Web of Science 核心合集中的 "被引频次": 0 
被引频次合计: 0 
摘要: A highly reliable interface of self-aligned barrier CuSiN thin layer between the Cu film and the nano-porous SiC:H (p-SiC:H) capping barrier (k=3.3) has been developed in the present work. With the introduction of self-aligned barrier (SAB) CuSiN between a Cu film and a p-SiC:H capping barrier, the interfacial thermal stability and the adhesion of the Cu/p-SiC:H film are considerably enhanced. A significant improvement of adhesion strength and thermal stability of Cu/p-SiC:H/SiOC:H film stack has been achieved by optimizing the pre-clean step before cap-layer deposition and by forming the CuSiN-like phase. This cap layer on the surface of the Cu can provide a more cohesive interface and effectively suppress Cu atom migration as well.
文献类型: Article
作者关键词: interfacial adhesion; thermal stability; self-aligned CuSiN process; diffusion barrier
KeyWords Plus: NANO-SCRATCH TECHNIQUE; NM TECHNOLOGY NODE; CARBON-FILMS; INTERCONNECTS; RESISTANCE; DIFFUSION; BARRIERS
Web of Science 类别: Physics, Fluids & Plasmas
研究方向: Physics
IDS 号: 983ML 
ISSN: 1009-0630 

第 88 条，共 210 条
标题: Optical planar waveguides in Yb3+-doped phosphate glasses produced by He+ ion implantation 
作者: Liu, CX (Liu Chun-Xiao); Li, WN (Li Wei-Nan); Wei, W (Wei Wei); Peng, B (Peng Bo)
来源出版物: CHINESE PHYSICS B  卷: 21  期: 7  文献号: 074211  DOI: 10.1088/1674-1056/21/7/074211  出版年: JUL 2012  
Web of Science 核心合集中的 "被引频次": 3 
被引频次合计: 3 
摘要: Optical planar waveguides in Yb3+-doped phosphate glasses are fabricated by implanting triple-energy helium ions. The guiding modes and the near-field intensity distribution are measured by using the prism-coupling method and the end-face coupling setup with a He-Ne laser at 633 nm The intensity calculation method (ICM) is used to reconstruct the refractive index profile of the waveguide. The absorption and the fluorescence investigations reveal that the glass bulk features are well preserved in the active volumes of the waveguides, suggesting the fabricated structures for possible applications as waveguide lasers.
文献类型: Article
作者关键词: waveguide; ion implantation; laser materials; photoluminescence
KeyWords Plus: LASER; FABRICATION; CRYSTALS; GAIN
Web of Science 类别: Physics, Multidisciplinary
研究方向: Physics
IDS 号: 976CO 
ISSN: 1674-1056 

第 89 条，共 210 条
标题: Spectroscopic properties of new Yb3+-doped TeO2-ZnO-Nb2O5 based tellurite glasses with high emission cross-section 
作者: Wang, CC (Wang, Cuicui); Wang, PF (Wang, Pengfei); Zheng, RL (Zheng, Ruilin); Xu, SN (Xu, Shennuo); Wei, W (Wei, Wei); Peng, B (Peng, Bo)
来源出版物: OPTICAL MATERIALS  卷: 34  期: 9  页: 1549-1552  DOI: 10.1016/j.optmat.2012.03.026  出版年: JUL 2012  
Web of Science 核心合集中的 "被引频次": 8 
被引频次合计: 8 
摘要: Novel Yb3+-doped TeO2-ZnO-Nb2O5 based tellurite glasses with high stimulated emission cross-section were prepared by melt-quenching method, and their spectroscopic and gain properties were investigated by means of absorption spectrum, fluorescence decay curve and fluorescence emission spectrum. The results show that the stimulated emission cross-section of the Pb2+-doped glass increases with the increase of PbF2 concentration. Toward the samples with co-existence of Pb2+ and Zr4+ ions, the stimulated emission cross-sections achieve 1.42 pm(2) and 1.48 pm(2) when PbF2 concentrations are 2 mol% and 6 mol%, respectively. All these indicate that the Yb3+-doped TeO2-ZnO-Nb2O5-PbF2-ZrF4 glasses are a good candidate working as an active laser media for solid lasers. (c) 2012 Elsevier B.V. All rights reserved.
文献类型: Article
作者关键词: Tellurite based glass; Absorption spectrum; Emission cross-section; Gain property
KeyWords Plus: HEAVY-METAL OXIDE; THERMAL-STABILITY; OPTICAL-PROPERTIES; NIOBIUM TELLURITE; LASER PROPERTIES; YB; YTTERBIUM; FIBER; FLUORESCENCE; ABSORPTION
Web of Science 类别: Materials Science, Multidisciplinary; Optics
研究方向: Materials Science; Optics
IDS 号: 971LM 
ISSN: 0925-3467 

第 90 条，共 210 条
标题: Spectrum reconstruction based on the constrained optimal linear inverse methods 
作者: Ren, WY (Ren, Wenyi); Zhang, CM (Zhang, Chunmin); Mu, TK (Mu, Tingkui); Dai, HS (Dai, Haishan)
来源出版物: OPTICS LETTERS  卷: 37  期: 13  页: 2580-2582  出版年: JUL 1 2012  
Web of Science 核心合集中的 "被引频次": 8 
被引频次合计: 8 
摘要: The dispersion effect of birefringent material results in spectrally varying Nyquist frequency for the Fourier transform spectrometer based on birefringent prism. Correct spectral information cannot be retrieved from the observed interferogram if the dispersion effect is not appropriately compensated. Some methods, such as nonuniform fast Fourier transforms and compensation method, were proposed to reconstruct the spectrum. In this Letter, an alternative constrained spectrum reconstruction method is suggested for the stationary polarization interference imaging spectrometer (SPIIS) based on the Savart polariscope. In the theoretical model of the interferogram, the noise and the total measurement error are included, and the spectrum reconstruction is performed by using the constrained optimal linear inverse methods. From numerical simulation, it is found that the proposed method is much more effective and robust than the nonconstrained spectrum reconstruction method proposed by Jian, and provides a useful spectrum reconstruction approach for the SPIIS. (C) 2012 Optical Society of America
PubMed ID: 22743461 
文献类型: Article
KeyWords Plus: INTERFERENCE IMAGING SPECTROMETER
Web of Science 类别: Optics
研究方向: Optics
IDS 号: 970CN 
ISSN: 0146-9592 

第 91 条，共 210 条
标题: Observation of pulse trapping in a near-zero dispersion regime 
作者: Mao, D (Mao, Dong); Liu, XM (Liu, Xueming); Lu, H (Lu, Hua)
来源出版物: OPTICS LETTERS  卷: 37  期: 13  页: 2619-2621  出版年: JUL 1 2012  
Web of Science 核心合集中的 "被引频次": 26 
被引频次合计: 27 
摘要: We report pulse trapping in passively mode-locked fiber lasers operating in a near-zero dispersion regime. Two polarization components of vector pulses have different central wavelengths while copropagating as a unit in fiber lasers. The vector pulses exhibit smooth Gaussian spectral profile without any sidebands, qualitatively distinct from those observed in net-anomalous and net-normal fiber lasers. Numerical simulations suggest that the pulse trapping depends not only on fiber birefringence and cavity dispersion but also on saturable absorption effect. The experimental observations are in good agreement with the numerical simulations. (C) 2012 Optical Society of America
PubMed ID: 22743473 
文献类型: Article
KeyWords Plus: LOCKED FIBER LASERS; OPTICAL FIBERS; DISSIPATIVE SOLITONS; VECTOR SOLITONS; WAVELENGTH
Web of Science 类别: Optics
研究方向: Optics
IDS 号: 970CN 
ISSN: 0146-9592 

第 92 条，共 210 条
标题: Image Super-Resolution With Sparse Neighbor Embedding 
作者: Gao, XB (Gao, Xinbo); Zhang, KB (Zhang, Kaibing); Tao, DC (Tao, Dacheng); Li, XL (Li, Xuelong)
来源出版物: IEEE TRANSACTIONS ON IMAGE PROCESSING  卷: 21  期: 7  页: 3194-3205  DOI: 10.1109/TIP.2012.2190080  出版年: JUL 2012  
Web of Science 核心合集中的 "被引频次": 17 
被引频次合计: 19 
摘要: Until now, neighbor-embedding-based (NE) algorithms for super-resolution (SR) have carried out two independent processes to synthesize high-resolution (HR) image patches. In the first process, neighbor search is performed using the Euclidean distance metric, and in the second process, the optimal weights are determined by solving a constrained least squares problem. However, the separate processes are not optimal. In this paper, we propose a sparse neighbor selection scheme for SR reconstruction. We first predetermine a larger number of neighbors as potential candidates and develop an extended Robust-SL0 algorithm to simultaneously find the neighbors and to solve the reconstruction weights. Recognizing that the k-nearest neighbor (k-NN) for reconstruction should have similar local geometric structures based on clustering, we employ a local statistical feature, namely histograms of oriented such clustering. By conveying local structural information of HoG in the synthesis stage, the k-NN of each LR input patch is adaptively chosen from their associated subset, which significantly improves the speed of synthesizing the HR image while preserving the quality of reconstruction. Experimental results suggest that the proposed method can achieve competitive SR quality compared with other state-of-the-art baselines.
PubMed ID: 22411005 
文献类型: Article
作者关键词: Histograms of oriented gradients (HoG); neighbor embedding (NE); sparse representation; super-resolution (SR)
KeyWords Plus: QUALITY ASSESSMENT; REPRESENTATION; INTERPOLATION; RECONSTRUCTION; ALGORITHM; NORM
Web of Science 类别: Computer Science, Artificial Intelligence; Engineering, Electrical & Electronic
研究方向: Computer Science; Engineering
IDS 号: 962WF 
ISSN: 1057-7149 

第 93 条，共 210 条
标题: Constrained Nonnegative Matrix Factorization for Image Representation 
作者: Liu, HF (Liu, Haifeng); Wu, ZH (Wu, Zhaohui); Li, XL (Li, Xuelong); Cai, D (Cai, Deng); Huang, TS (Huang, Thomas S.)
来源出版物: IEEE TRANSACTIONS ON PATTERN ANALYSIS AND MACHINE INTELLIGENCE  卷: 34  期: 7  页: 1299-1311  DOI: 10.1109/TPAMI.2011.217  出版年: JUL 2012  
Web of Science 核心合集中的 "被引频次": 17 
被引频次合计: 21 
摘要: Nonnegative matrix factorization (NMF) is a popular technique for finding parts-based, linear representations of nonnegative data. It has been successfully applied in a wide range of applications such as pattern recognition, information retrieval, and computer vision. However, NMF is essentially an unsupervised method and cannot make use of label information. In this paper, we propose a novel semi-supervised matrix decomposition method, called Constrained Nonnegative Matrix Factorization (CNMF), which incorporates the label information as additional constraints. Specifically, we show how explicitly combining label information improves the discriminating power of the resulting matrix decomposition. We explore the proposed CNMF method with two cost function formulations and provide the corresponding update solutions for the optimization problems. Empirical experiments demonstrate the effectiveness of our novel algorithm in comparison to the state-of-the-art approaches through a set of evaluations based on real-world applications.
文献类型: Article
作者关键词: Nonnegative matrix factorization; semi-supervised learning; dimension reduction; clustering
KeyWords Plus: GRADIENT; MANIFOLD; PARTS
Web of Science 类别: Computer Science, Artificial Intelligence; Engineering, Electrical & Electronic
研究方向: Computer Science; Engineering
IDS 号: 943PZ 
ISSN: 0162-8828 

第 94 条，共 210 条
标题: Principle and analysis of a moving double-sided mirror interferometer 
作者: Yang, QH (Yang, Qinghua); Zhao, BC (Zhao, Baochang); Wen, DS (Wen, Desheng)
来源出版物: OPTICS AND LASER TECHNOLOGY  卷: 44  期: 5  页: 1256-1260  DOI: 10.1016/j.optlastec.2012.01.001  出版年: JUL 2012  
Web of Science 核心合集中的 "被引频次": 4 
被引频次合计: 5 
摘要: A moving double-sided mirror interferometer (MDSMI) is presented. It comprises one moving double-sided mirror (MDSM), one fixed corner-cube mirror, one fixed plane mirror, and one beam-splitter. The MDSM is a plane-parallel glass plate with both faces coated with high-reflectivity films. The optical path difference (OPD) is created by the straight reciprocating motion of the MDSM driven by a linear actuator, and the OPD value is four times the displacement of the MDSM without tilt. The effect of tilt of the MDSM is analyzed, and the tilt tolerance of the MDSM is systematically analyzed by means of modulation depth and phase error. The MDSMI is very suitable for high-resolution rapid-scan infrared spectrometers. (C) 2012 Elsevier Ltd. All rights reserved.
文献类型: Article
作者关键词: Interferometer; Moving double-sided mirror; Tilt tolerance
KeyWords Plus: FOURIER-TRANSFORM SPECTROSCOPY; CUBE-CORNER INTERFEROMETER; MICHELSON INTERFEROMETER; RESOLUTION; PERFORMANCE; INFORMATION; DESIGN; IR
Web of Science 类别: Optics; Physics, Applied
研究方向: Optics; Physics
IDS 号: 910BE 
ISSN: 0030-3992 

第 95 条，共 210 条
标题: Signal-to-noise ratio of ultrashort pulses enhanced by a fiber Sagnac loop 
作者: Sun, QB (Sun, Qibing); Liu, HJ (Liu, Hongjun); Huang, N (Huang, Nan); Zhao, W (Zhao, Wei)
来源出版物: OPTICS AND LASER TECHNOLOGY  卷: 44  期: 5  页: 1328-1332  DOI: 10.1016/j.optlastec.2011.12.035  出版年: JUL 2012  
Web of Science 核心合集中的 "被引频次": 0 
被引频次合计: 0 
摘要: A method to enhance the signal-to-noise ratio of ultrashort pulses is presented with picosecond pulses as an example. Numerical simulation and analysis show that the signal-to-noise ratio can be improved by four orders of magnitude using a fiber Sagnac loop with two different fibers. It is also found that there is an optimal length of the fiber for improving the signal-to-noise ratio. This is a useful method for improving the signal-to-noise ratio of the seed light in the chirped pulse amplification (CPA) or optical parametric chirped pulse amplification (OPCPA) systems. (C) 2011 Elsevier Ltd. All rights reserved.
文献类型: Article
作者关键词: Signal-to-noise ratio; A fiber Sagnac loop; OPCPA
KeyWords Plus: PARAMETRIC-AMPLIFIER; MULTI-TERAWATT; MIRROR; SUPPRESSION; REDUCTION; LASERS; SYSTEM
Web of Science 类别: Optics; Physics, Applied
研究方向: Optics; Physics
IDS 号: 910BE 
ISSN: 0030-3992 

第 96 条，共 210 条
标题: A neodymium fluid laser: Laser emission in circulating state 
作者: Hou, CQ (Hou, Chaoqi); Guo, HT (Guo, Haitao); She, JB (She, Jiangbo); Cui, XX (Cui, Xiaoxia); Qiao, ZB (Qiao, Zebang); Gao, F (Gao, Fei); Lu, M (Lu, Min); Wei, W (Wei, Wei); Peng, B (Peng, Bo)
来源出版物: OPTICS AND LASER TECHNOLOGY  卷: 44  期: 5  页: 1633-1635  DOI: 10.1016/j.optlastec.2011.12.047  出版年: JUL 2012  
Web of Science 核心合集中的 "被引频次": 0 
被引频次合计: 2 
摘要: Differing from conventional liquid lasers, a novel concept of fluid laser was provided, which has attractively potential using in high average power lasers. The laser medium was prepared by dispersing Nd3+: phosphate glass micro-balls in organic match liquid. Its optical properties were investigated and the radiative transition rate was calculated by Judd-Ofelt theory. The experiment of laser oscillation in static state indicates that the heat exchanging has limited effect on refractive index of the fluid laser medium in a short time. In circulating state, a laser oscillation occurred at 1058.1 nm when pumped by two 808 nm diode lasers. The maximum output energy is 2.58 mJ with the absorbed pumping energy of 460 mJ. This study offers a new way in the exploration of high average power laser. (C) 2012 Elsevier Ltd. All rights reserved.
文献类型: Article
作者关键词: Laser materials; Lasers; Neodymium
KeyWords Plus: RARE-EARTH IONS; INTENSITIES
Web of Science 类别: Optics; Physics, Applied
研究方向: Optics; Physics
IDS 号: 910BE 
ISSN: 0030-3992 

第 97 条，共 210 条
标题: Development of a stable dielectric-barrier discharge enhanced laminar plasma jet generated at atmospheric pressure 
作者: Tang, J (Tang, Jie); Li, SB (Li, Shibo); Zhao, W (Zhao, Wei); Wang, YS (Wang, Yishan); Duan, YX (Duan, Yixiang)
来源出版物: APPLIED PHYSICS LETTERS  卷: 100  期: 25  文献号: 253505  DOI: 10.1063/1.4729818  出版年: JUN 18 2012  
Web of Science 核心合集中的 "被引频次": 10 
被引频次合计: 11 
摘要: A stable nonthermal laminar atmospheric-pressure plasma source equipped with dielectric-barrier discharge was developed to realize more efficient plasma generation, with the total energy consumption reduced to nearly 25% of the original. Temperature and emission spectra monitoring indicates that this plasma is uniform in the lateral direction of the jet core region. It is also found that this plasma contains not only abundant excited argon atoms but also sufficient excited N-2 and OH. This is mainly resulted from the escape of abundant electrons from the exit, due to the sharp decrease of sustaining voltage and the coupling between ions and electrons. (C) 2012 American Institute of Physics. [http://dx.doi.org/10.1063/1.4729818]
文献类型: Article
KeyWords Plus: CORONA DISCHARGE; GLOW-DISCHARGE; ELECTRODE; KRYPTON; ARGON; AIR
Web of Science 类别: Physics, Applied
研究方向: Physics
IDS 号: 964EL 
ISSN: 0003-6951 

第 98 条，共 210 条
标题: Analysis of temporal broadening of optical pulses by atmospheric dispersion in laser communication system 
作者: Lu, HQ (Lu, Hongqiang); Zhao, W (Zhao, Wei); Xie, XP (Xie, Xiaoping)
来源出版物: OPTICS COMMUNICATIONS  卷: 285  期: 13-14  页: 3169-3173  DOI: 10.1016/j.optcom.2012.02.094  出版年: JUN 15 2012  
Web of Science 核心合集中的 "被引频次": 1 
被引频次合计: 2 
摘要: In this paper, pulse broadening caused by atmospheric dispersion is analyzed, which is the key factor in high-speed and long-distance free space laser communication systems according to our simulation. The measured datum of atmospheric parameters, including atmospheric pressure and atmospheric temperature of the desert in Xinjiang. China, is used in the analysis of pulses broadening. The pulse broadening caused by atmospheric dispersion is very significant when pulsewidth is on the order of 5 ps, and pulse broadening is negligible if the pulsewidth is larger than 20 ps. With the increment of optical wavelength, atmospheric dispersion-induced pulse broadening is mitigated. The received pulsewidth is dominated mainly by dispersion-induced pulse broadening at small duty ratio of original signal, and original pulsewidth at large duty ratio of original signal respectively. By selecting proper duty ratio of optical pulse, the received pulsewidth can be minimized and the system bit rate can be maximized. (c) 2012 Elsevier B.V. All rights reserved.
文献类型: Article
作者关键词: Atmospheric dispersion; Pulse broadening; Free space laser communication
KeyWords Plus: FREE-SPACE TRANSMISSION; TURBULENCE; PROPAGATION; FOG
Web of Science 类别: Optics
研究方向: Optics
IDS 号: 936ZX 
ISSN: 0030-4018 

第 99 条，共 210 条
标题: Defect modes supported by optical lattices in photovoltaic-photorefractive crystals 
作者: Li, KH (Li, Kehao); Lu, KQ (Lu, Keqing); Guo, JB (Guo, Jianbang); Chen, WJ (Chen, Weijun); Sun, TT (Sun, Tongtong); Yao, FX (Yao, Fengxue); Xu, JJ (Xu, Jingjun)
来源出版物: OPTICS COMMUNICATIONS  卷: 285  期: 13-14  页: 3187-3190  DOI: 10.1016/j.optcom.2012.03.003  出版年: JUN 15 2012  
Web of Science 核心合集中的 "被引频次": 2 
被引频次合计: 2 
摘要: We study defect modes in optically induced one-dimensional lattices in photovoltaic-photorefractive crystals. These defect modes exist in different bandgaps due to the change of defect intensity. For a positive defect, defect mode branches exist not only in the semi-infinite bandgap, but also in the first and second bandgaps. When the defect mode branch is fixed, the confinement of defect modes increases with the defect strength parameter. For a negative defect, defect mode branches exist only in the first and second bandgaps. For a given defect mode branch, the strongest confinement of the defect modes appears when the lattice intensity at the defect site is not the smallest in its branch. On the other hand, when the defect strength parameter is fixed, the most localized defect modes arise in the semi-infinite bandgap for the positive defect and in the first bandgap for the negative defect. Crown Copyright (c) 2012 Published by Elsevier B.V. All rights reserved.
文献类型: Article
作者关键词: Defect modes; Photovoltaic effect; Optical lattices; Nonlinear optics
KeyWords Plus: 2-DIMENSIONAL PHOTONIC LATTICES; SOLITONS; DIPOLE
Web of Science 类别: Optics
研究方向: Optics
IDS 号: 936ZX 
ISSN: 0030-4018 

第 100 条，共 210 条
标题: Control of ultrafast laser-induced bulk nanogratings in fused silica via pulse time envelopes 
作者: Mauclair, C (Mauclair, C.); Zamfirescu, M (Zamfirescu, M.); Colombier, JP (Colombier, J. P.); Cheng, G (Cheng, G.); Mishchik, K (Mishchik, K.); Audouard, E (Audouard, E.); Stoian, R (Stoian, R.)
来源出版物: OPTICS EXPRESS  卷: 20  期: 12  页: 12997-13005  DOI: 10.1364/OE.20.012997  出版年: JUN 4 2012  
Web of Science 核心合集中的 "被引频次": 8 
被引频次合计: 9 
摘要: Employing a method of in-situ control we propose an approach for the optimization of self-arranged nanogratings in bulk fused silica under the action of ultrashort laser pulses with programmable time envelopes. A parametric study of the influence of the pulse duration and temporal form asymmetries is given. Using the diffraction properties of the laser-triggered subwavelength patterns we monitor and regulate the period and the quality of the periodic nanoscale arrangement via the effective nonlinear excitation dose. Periodicity tuning on tens of nanometers can be achieved by pulse temporal variations, with a minimum around 0.7 ps at the chosen powers. Equally, strong sensitivity to pulse asymmetries is observed. The driving factor is related to increasing carrier densities due to nonlinear confinement and the development of extended nanoroughness domains upon multiple exposure, creating a pulse-dependent effective accumulation dose via a morpho-dimensional effect. The result may impact the associated optical functions. (C) 2012 Optical Society of America
PubMed ID: 22714327 
文献类型: Article
KeyWords Plus: SURFACE; GLASS; IONIZATION
Web of Science 类别: Optics
研究方向: Optics
IDS 号: 961KP 
ISSN: 1094-4087 

第 101 条，共 210 条
标题: Key technology on all-plastic optical life detection instrument 
作者: Kong, DP (Kong De-Peng); Wang, JM (Wang Jin-Meng); Wang, LL (Wang Li-Li); He, ZQ (He Zheng-Quan); Li, YL (Li Yu-Lin); Dou, ZZ (Dou Zhi-Zhong)
来源出版物: ACTA PHYSICA SINICA  卷: 61  期: 12  文献号: 124215  出版年: JUN 2012  
Web of Science 核心合集中的 "被引频次": 0 
被引频次合计: 0 
摘要: Plastic fiber image bundle with 250 single fiber diameter, 4096 pixels, 15 m length is fabricated. The result indicates that 25% of the input image remains after it has translated though the 15m fiber bundle, which can meet the need of eye observation or CCD image capture. Based on the key component of image bundle, the eye observation life detection instrument prototype and intelligent life detection instrument prototype connected with CCD, image capture card and portable computer are designed and produced. The effectiveness of researching and rescuing the person from danger is demonstrated. The system can be used not only for researching and rescuing the buried person, but also for video monitoring some special occasions, such as strong electromagnetic interference environment, security department and explosive places.
文献类型: Article
作者关键词: plastic fiber; image bundle; fiber endoscope; post-earthquake research and rescue
Web of Science 类别: Physics, Multidisciplinary
研究方向: Physics
IDS 号: 973XS 
ISSN: 1000-3290 

第 102 条，共 210 条
标题: Design and analysis of thermally tunable liquid-crystal-filled microstructured polymer optical fiber 
作者: Wang, DD (Wang Dou-Dou); Wang, LL (Wang Li-Li); Li, DD (Li Dong-Dong)
来源出版物: ACTA PHYSICA SINICA  卷: 61  期: 12  文献号: 128101  出版年: JUN 2012  
Web of Science 核心合集中的 "被引频次": 1 
被引频次合计: 2 
摘要: A highly tunable bandgap-guiding microstructured polymer optical fiber (mPOF) is designed by infiltrating the cladding air holes with a liquid crystal. Bandgap is blue shifted as temperature is increased. A high thermal tuning sensitivity of -5.5 nm/degrees C is achieved at the long-wavelength edge of the bandgap. Mode properties and effective mode area of the fundamental mode are investigated by using the full-vector finite element method. The designed fiber has a large effective area and high power transmission coefficient between the index guiding modes and the bandgap guiding modes. Our results provide theoretical references for applications of mPOF in sensing and tunable fiber-optic devices.
文献类型: Article
作者关键词: microstructured polymer optical fiber; liquid crystal; photonic bandgap; finite element method
KeyWords Plus: PHOTONIC BANDGAP FIBERS; PROPAGATION; DISPERSION; AREA
Web of Science 类别: Physics, Multidisciplinary
研究方向: Physics
IDS 号: 973XS 
ISSN: 1000-3290 

第 103 条，共 210 条
标题: First principles investigation of L-alanine in terahertz region 
作者: Zheng, ZP (Zheng, Zhuan-Ping); Fan, WH (Fan, Wen-Hui)
来源出版物: JOURNAL OF BIOLOGICAL PHYSICS  卷: 38  期: 3  页: 405-413  DOI: 10.1007/s10867-012-9261-0  出版年: JUN 2012  
Web of Science 核心合集中的 "被引频次": 1 
被引频次合计: 1 
摘要: Terahertz absorption spectrum (0.5-4.0 THz) of L-alanine in the solid phase was measured by terahertz time-domain spectroscopy at room temperature. Simulations utilizing gaseous-state and solid-state theory were performed to determine the origins of the observed vibrational features. Our calculations showed that the measured features in solid-state materials could be well understood by considering the crystal packing interactions in a solid-state density functional theory calculation. Furthermore, intermolecular vibrations of L-alanine are found to be the dominating contributions to these measured spectral features in the range of 0.5-4.0 THz, except that located at 3.11 THz.
PubMed ID: 23729906 
文献类型: Article
作者关键词: THz-TDS; L-alanine; Solid-state theory
KeyWords Plus: TIME-DOMAIN SPECTROSCOPY; VIBRATIONAL-SPECTRA; PULSE SPECTROSCOPY; RAMAN-SPECTROSCOPY; AMINO-ACIDS; DL-ALANINE; STATE; CRYSTAL; CANCER
Web of Science 类别: Biophysics
研究方向: Biophysics
IDS 号: 968DQ 
ISSN: 0092-0606 

第 104 条，共 210 条
标题: Observation of linewidth narrowing due to a spontaneously generated coherence effect 
作者: Tian, SC (Tian Si-Cong); Wang, CL (Wang Chun-Liang); Kang, ZH (Kang Zhi-Hui); Yang, XB (Yang Xiu-Bin); Wan, RG (Wan Ren-Gang); Zhang, XJ (Zhang Xiao-Jun); Zhang, H (Zhang Hang); Jiang, Y (Jiang Yun); Cui, HN (Cui Hai-Ning); Gao, JY (Gao Jin-Yue)
来源出版物: CHINESE PHYSICS B  卷: 21  期: 6  文献号: 064206  DOI: 10.1088/1674-1056/21/6/064206  出版年: JUN 2012  
Web of Science 核心合集中的 "被引频次": 0 
被引频次合计: 0 
摘要: We investigate the resonance fluorescence spectrum of an atomic three-level ladder system driven by two laser fields. We show that such a system emulates to a large degree a V-type atom with parallel dipole moments-the latter being a system that exhibits spontaneously generated coherence and can display ultrasharp spectral lines. We find a suitable energy scheme in a Rb-85 atom and experimentally observe the narrowing of the central peak in a rubidium atomic beam. The corresponding spectrum can convincingly demonstrate the existence of spontaneously generated coherence.
文献类型: Article
作者关键词: spontaneously generated coherence; resonance fluorescence; linewidth narrowing; atomic beam
KeyWords Plus: SPONTANEOUS EMISSION CANCELLATION; 4-LEVEL ATOMIC SYSTEM; DRIVEN 3-LEVEL SYSTEM; RESONANCE-FLUORESCENCE; QUANTUM INTERFERENCE; ABSORPTION PROPERTIES; MONOCHROMATIC-FIELD; 2-LEVEL ATOM; SPECTRUM; VACUUM
Web of Science 类别: Physics, Multidisciplinary
研究方向: Physics
IDS 号: 960QV 
ISSN: 1674-1056 

第 105 条，共 210 条
标题: Design of polarity-preserved or polarity-inverted wavelength converters using cross-phase modulation in a highly nonlinear photonic crystal fiber with flat dispersion 
作者: Hui, ZQ (Hui, Zhan-Qiang); Zhang, JG (Zhang, Jian-Guo)
来源出版物: JOURNAL OF OPTICS  卷: 14  期: 6  文献号: 065402  DOI: 10.1088/2040-8978/14/6/065402  出版年: JUN 2012  
Web of Science 核心合集中的 "被引频次": 3 
被引频次合计: 3 
摘要: In this paper, we propose the design of tunable and robust wavelength converters which can perform the polarity-preserved or polarity-inverted wavelength conversion by using the cross-phase modulation (XPM) in a dispersion-flattened highly nonlinear photonic crystal fiber (DF-HNL-PCF). The newly designed wavelength converter consists of a DF-HNL-PCF and an optical band-pass filter in the simple straight-line configuration, where XPM leads to broadening the spectrum of a continuous-wave probe light and the polarity-preserved, tunable wavelength conversion is then implemented by filtering out the blue-chirped or red-chirped spectral component of a probe light. The experimental results show that the polarity-preserved wavelength converter using a DF-HNL-PCF can achieve the error-free conversion of 10 Gbit s(-1) optical data signals with the maximum power penalty of less than 2.1 dB over a wavelength range of nearly 34 nm. This wavelength tunability is actually limited by an operational wavelength range of the tunable optical band-pass filter that is used to extract the wavelength-converted signal in our experiment. Moreover, the polarity-inverted wavelength conversion is observed at the XPM-based wavelength converter using a DF-HNL-PCF, for the first time. This is achieved by tuning the central wavelength of an optical band-pass filter to coincide with that of a chirped probe light.
文献类型: Article
作者关键词: wavelength conversion; photonic crystal fiber; cross-phase modulation; optical fiber communication; highly nonlinear fiber
KeyWords Plus: OPTICAL-FIBER; 40 GBIT/S; CONVERSION; XPM; SIGNALS; GB/S
Web of Science 类别: Optics
研究方向: Optics
IDS 号: 960LY 
ISSN: 2040-8978 

第 106 条，共 210 条
标题: Efficient optical Kerr gate of tellurite glass for acquiring ultrafast fluorescence 
作者: Zhang, H (Zhang, Hang); Zhou, ZG (Zhou, Zhiguang); Lin, AX (Lin, Aoxiang); Cheng, J (Cheng, Jun); Liu, H (Liu, Hui); Si, JH (Si, Jinhai); Chen, F (Chen, Feng); Hou, X (Hou, Xun)
来源出版物: JOURNAL OF OPTICS  卷: 14  期: 6  文献号: 065201  DOI: 10.1088/2040-8978/14/6/065201  出版年: JUN 2012  
Web of Science 核心合集中的 "被引频次": 3 
被引频次合计: 3 
摘要: We investigated the ultrafast optical Kerr effect of tellurite glass (Te glass) by the femtosecond time-resolved pump-probe technique. The Kerr-gated spectra from a chirped supercontinuum (SC) obtained by a Te glass optical Kerr gate (OKG) were of a narrow bandwidth and wide range of transmittance spectra. Time-resolved violet fluorescence of a ZnO thin film with high temporal resolution was measured using the Te glass OKG. Experimental results showed that Te glass was a good candidate for an OKG medium due to its ultrafast response, large transmittance window, and large nonlinear refractive index.
文献类型: Article
作者关键词: femtosecond; optical Kerr gate; tellurite glass; ultrafast response; nonlinear refractive index
KeyWords Plus: RESOLVED LUMINESCENCE SPECTROSCOPY; EPITAXIAL THIN-FILMS; CHALCOGENIDE GLASSES; OXIDE GLASSES; NONLINEARITY; PHTHALOCYANINE; DYNAMICS; CARRIERS; SHUTTER
Web of Science 类别: Optics
研究方向: Optics
IDS 号: 960LY 
ISSN: 2040-8978 

第 107 条，共 210 条
标题: Detection of Sudden Pedestrian Crossings for Driving Assistance Systems 
作者: Xu, YW (Xu, Yanwu); Xu, D (Xu, Dong); Lin, S (Lin, Stephen); Han, TX (Han, Tony X.); Cao, XB (Cao, Xianbin); Li, XL (Li, Xuelong)
来源出版物: IEEE TRANSACTIONS ON SYSTEMS MAN AND CYBERNETICS PART B-CYBERNETICS  卷: 42  期: 3  页: 729-739  DOI: 10.1109/TSMCB.2011.2175726  出版年: JUN 2012  
Web of Science 核心合集中的 "被引频次": 3 
被引频次合计: 3 
摘要: In this paper, we study the problem of detecting sudden pedestrian crossings to assist drivers in avoiding accidents. This application has two major requirements: to detect crossing pedestrians as early as possible just as they enter the view of the car-mounted camera and to maintain a false alarm rate as low as possible for practical purposes. Although many current sliding-window-based approaches using various features and classification algorithms have been proposed for image-/video-based pedestrian detection, their performance in terms of accuracy and processing speed falls far short of practical application requirements. To address this problem, we propose a three-level coarse-to-fine video-based framework that detects partially visible pedestrians just as they enter the camera view, with low false alarm rate and high speed. The framework is tested on a new collection of high-resolution videos captured from a moving vehicle and yields a performance better than that of state-of-the-art pedestrian detection while running at a frame rate of 55 fps.
PubMed ID: 22147306 
文献类型: Article
作者关键词: Coarse to fine; pedestrian detection; performance evaluation; spatiotemporal refinement; sudden pedestrian crossing
KeyWords Plus: OBJECT TRACKING; CLASSIFICATION; FEATURES; SURVEILLANCE; MOTION; GAIT; SEGMENTATION; RECOGNITION; PATTERNS; SCENES
Web of Science 类别: Automation & Control Systems; Computer Science, Artificial Intelligence; Computer Science, Cybernetics
研究方向: Automation & Control Systems; Computer Science
IDS 号: 943YE 
ISSN: 1083-4419 

第 108 条，共 210 条
标题: Segmenting Human From Photo Images Based on a Coarse-to-Fine Scheme 
作者: Lu, HC (Lu, Huchuan); Fang, GL (Fang, Guoliang); Shao, XQ (Shao, Xinqing); Li, XL (Li, Xuelong)
来源出版物: IEEE TRANSACTIONS ON SYSTEMS MAN AND CYBERNETICS PART B-CYBERNETICS  卷: 42  期: 3  页: 889-899  DOI: 10.1109/TSMCB.2011.2182048  出版年: JUN 2012  
Web of Science 核心合集中的 "被引频次": 6 
被引频次合计: 6 
摘要: Human segmentation in photo images is a challenging and important problem that finds numerous applications ranging from album making and photo classification to image retrieval. Previous works on human segmentation usually demand a time-consuming training phase for complex shape-matching processes. In this paper, we propose a straightforward framework to automatically recover human bodies from color photos. Employing a coarse-to-fine strategy, we first detect a coarse torso (CT) using the multicue CT detection algorithm and then extract the accurate region of the upper body. Then, an iterative multiple oblique histogram algorithm is presented to accurately recover the lower body based on human kinematics. The performance of our algorithm is evaluated on our own data set (contains 197 images with human body region ground truth data), VOC 2006, and the 2010 data set. Experimental results demonstrate the merits of the proposed method in segmenting a person with various poses.
PubMed ID: 22275719 
文献类型: Article
作者关键词: Graph cuts; human segmentation; multicue coarse torso detection algorithm (MCTD); multiple oblique histogram (MOH)
KeyWords Plus: HUMAN-BODY CONFIGURATIONS; PICTORIAL STRUCTURES; NORMALIZED CUTS; POSE ESTIMATION; SEGMENTATION; RECOGNITION; CONTOUR; PEOPLE
Web of Science 类别: Automation & Control Systems; Computer Science, Artificial Intelligence; Computer Science, Cybernetics
研究方向: Automation & Control Systems; Computer Science
IDS 号: 943YE 
ISSN: 1083-4419 

第 109 条，共 210 条
标题: Robust Alternative Minimization for Matrix Completion 
作者: Lu, XQ (Lu, Xiaoqiang); Gong, TL (Gong, Tieliang); Yan, PK (Yan, Pingkun); Yuan, Y (Yuan, Yuan); Li, XL (Li, Xuelong)
来源出版物: IEEE TRANSACTIONS ON SYSTEMS MAN AND CYBERNETICS PART B-CYBERNETICS  卷: 42  期: 3  页: 939-949  DOI: 10.1109/TSMCB.2012.2185490  出版年: JUN 2012  
Web of Science 核心合集中的 "被引频次": 2 
被引频次合计: 2 
摘要: Recently, much attention has been drawn to the problem of matrix completion, which arises in a number of fields, including computer vision, pattern recognition, sensor network, and recommendation systems. This paper proposes a novel algorithm, named robust alternative minimization (RAM), which is based on the constraint of low rank to complete an unknown matrix. The proposed RAM algorithm can effectively reduce the relative reconstruction error of the recovered matrix. It is numerically easier to minimize the objective function and more stable for large-scale matrix completion compared with other existing methods. It is robust and efficient for low-rank matrix completion, and the convergence of the RAM algorithm is also established. Numerical results showed that both the recovery accuracy and running time of the RAM algorithm are competitive with other reported methods. Moreover, the applications of the RAM algorithm to low-rank image recovery demonstrated that it achieves satisfactory performance.
PubMed ID: 22345545 
文献类型: Article
作者关键词: Computer vision; convex optimization; image processing; low-rank matrices; matrix completion; nuclear norm minimization; pattern recognition; singular value decomposition (SVD)
KeyWords Plus: LOW-RANK MATRIX; NORM MINIMIZATION; RECOVERY; FACTORIZATION; ALGORITHMS; PROGRAMS; MOTION
Web of Science 类别: Automation & Control Systems; Computer Science, Artificial Intelligence; Computer Science, Cybernetics
研究方向: Automation & Control Systems; Computer Science
IDS 号: 943YE 
ISSN: 1083-4419 

第 110 条，共 210 条
标题: Defect modes in optically induced photonic lattices in biased photovoltaic-photorefractive crystals 
作者: Lu, KQ (Lu, Keqing); Guo, JB (Guo, Jianbang); Li, KH (Li, Kehao); Chen, WJ (Chen, Weijun); Sun, TT (Sun, Tongtong); Yao, FX (Yao, Fengxue); Niu, PJ (Niu, Pingjuan); Xu, JJ (Xu, Jingjun)
来源出版物: OPTICAL MATERIALS  卷: 34  期: 8  页: 1277-1281  DOI: 10.1016/j.optmat.2012.01.036  出版年: JUN 2012  
Web of Science 核心合集中的 "被引频次": 1 
被引频次合计: 1 
摘要: We show that defect modes in optically induced photonic lattices are possible in biased photovoltaic-photorefractive crystals. These defect modes exist in different bandgaps when the defect strength is changed. When the defect strength is positive, there is a defect-mode branch in each bandgap. When the defect strength is negative, there is a defect-mode branch in the first bandgap and are many defect-mode branches in higher bandgaps. For a given defect strength, the strongest confinement of the defect modes appears in the semi-infinite bandgap when the defect strength is positive and in the first bandgap when the defect strength is negative. On the other hand, these defect modes are those studied previously in optically induced photonic lattices in biased non-photovoltaic-photorefractive crystals when the bulk photovoltaic effect is negligible and predict those in optically induced photonic lattices in photovoltaic-photorefractive crystals when the external bias field is absent. Crown Copyright (C) 2012 Published by Elsevier B.V. All rights reserved.
文献类型: Article
作者关键词: Defect solitons; Photonic lattices; Photorefractive effect; Non-linear optics
KeyWords Plus: SOLITONS
Web of Science 类别: Materials Science, Multidisciplinary; Optics
研究方向: Materials Science; Optics
IDS 号: 944ST 
ISSN: 0925-3467 

第 111 条，共 210 条
标题: Theoretical Analysis on scanning spectral filter based on the bi-refraction electro-optical interferometer for pulse contrast improvement in femtosecond laser 
作者: Ma, ZR (Ma, Zairu); Sui, Z (Sui, Zhan); Feng, GY (Feng, Guoying); Sun, NC (Sun, Nianchun); Wang, YS (Wang, Yishan); Zhang, B (Zhang, Bin); Chen, JG (Chen, Jianguo)
来源出版物: OPTICS COMMUNICATIONS  卷: 285  期: 12  页: 2883-2888  DOI: 10.1016/j.optcom.2012.02.018  出版年: JUN 1 2012  
Web of Science 核心合集中的 "被引频次": 1 
被引频次合计: 1 
摘要: A spectral scanning filter method to improve the pulse contrast in the femtosecond chains is proposed, which is made using of the character that the instantaneous frequency varies with the time approximately linearly for the chirped pulse in the time-frequency domain. A spectral scanning filter based on the bi-refraction electro-optical interferometer is proposed and analyzed. The spectral scanning filter for reducing the ASE intensity is analyzed in the time-frequency domain by using the Short-Time Fourier Transformation method. The results show that the pulse contrast can be improved by two orders, and the transmission efficiency of the chirped pulse can exceed 85% when the synchronizing time jitter ranges from -50 ps to 50 ps adopting the cascaded filter method. The great advantage of this novel nonlinear spectral filter technology fits the high energy and high peak intensity femtosecond chains for it filters the ASE in the near field in temporal domain. (C) 2012 Elsevier B.V. All rights reserved.
文献类型: Article
作者关键词: Ultrafast optics; Wavelength filtering devices; Spectral scanning filter
KeyWords Plus: HIGH-ENERGY; TEMPORAL CONTRAST; AMPLIFICATION; GENERATION
Web of Science 类别: Optics
研究方向: Optics
IDS 号: 936ZV 
ISSN: 0030-4018 

第 112 条，共 210 条
标题: Intense red upconversion emission of Yb/Tm/Ho triply-doped tellurite glasses 
作者: Zhan, H (Zhan, Huan); Zhou, ZG (Zhou, Zhiguang); He, JL (He, Jianli); Lin, AX (Lin, Aoxiang)
来源出版物: APPLIED OPTICS  卷: 51  期: 15  页: 3091-3095  DOI: 10.1364/AO.51.003091  出版年: MAY 20 2012  
Web of Science 核心合集中的 "被引频次": 1 
被引频次合计: 1 
摘要: By conventional melting and quenching methods, 3Yb(2)O(3)-0.2Tm(2)O(3)-xHo(2)O(3) (wt%, x = 0.2 similar to 1.2) was doped into an easily fiberized tellurite glass with composition of 78TeO(2)-10ZnO-12Na(2)O (mol%) to form YTH-TZN78 glasses. Under 976 nm excitation, the direct sensitizing effect of Yb ions (Yb -> Ho) and indirect sensitizing and self-depopulating effects of Tm ions (Yb -> Tm -> Ho) were found to present intense red upconversion emission at 657 nm (Red, Ho: F-5(5) -> I-5(8)) and were responsible for the absence of the usually observed 484 nm emission (Blue, Tm: (1)G(4) -> H-3(6)). Regardless of the dopant concentration of Ho ions, the intensity of the red emission at 657 nm (Red, Ho: 5F5. 5I8) is about three times stronger than that of the green one at 543 nm (Green, Ho: S-5(2) -> I-5(8)). For this certain red emission at 657 nm, 0.4 wt% Ho2O3-doped YTH-TZN78 glass was found to present the highest emission intensity and is therefore determined as a promising active tellurite glass for red fiber laser development. (C) 2012 Optical Society of America
PubMed ID: 22614614 
文献类型: Article
KeyWords Plus: FIBER; GREEN; LASER; YB3+; LUMINESCENCE; BLUE
Web of Science 类别: Optics
研究方向: Optics
IDS 号: 945AY 
ISSN: 1559-128X 
电子 ISSN: 2155-3165 

第 113 条，共 210 条
标题: Fully affine invariant SURF for image matching 
作者: Pang, YW (Pang, Yanwei); Li, W (Li, Wei); Yuan, Y (Yuan, Yuan); Pan, J (Pan, Jing)
来源出版物: NEUROCOMPUTING  卷: 85  页: 6-10  DOI: 10.1016/j.neucom.2011.12.006  出版年: MAY 15 2012  
Web of Science 核心合集中的 "被引频次": 30 
被引频次合计: 33 
摘要: Fast and robust feature extraction is crucial for many computer vision applications such as image matching. The representative and the state-of-the-art image features include Scale Invariant Feature Transform (SIFT), Speeded Up Robust Features (SURF), and Affine SIFT (ASIFT). However, neither of them is fully affine invariant and computation efficient at the same time. To overcome this problem, we propose in this paper a fully affine invariant SURF algorithm. The proposed algorithm makes full use of the affine invariant advantage of ASIFT and the efficient merit of SURF while avoids their drawbacks. Experimental results on applications of image matching demonstrate the robustness and efficiency of the proposed algorithm. (c) 2012 Elsevier B.V. All rights reserved.
文献类型: Article
作者关键词: Feature extraction; Image matching; FAIR-SURF; SURF
KeyWords Plus: SELECTION; FEATURES
Web of Science 类别: Computer Science, Artificial Intelligence
研究方向: Computer Science
IDS 号: 928GX 
ISSN: 0925-2312 

第 114 条，共 210 条
标题: Plasmonic analog of electromagnetically induced transparency in multi-nanoresonator-coupled waveguide systems 
作者: Lu, H (Lu, Hua); Liu, XM (Liu, Xueming); Mao, D (Mao, Dong)
来源出版物: PHYSICAL REVIEW A  卷: 85  期: 5  文献号: 053803  DOI: 10.1103/PhysRevA.85.053803  出版年: MAY 4 2012  
Web of Science 核心合集中的 "被引频次": 29 
被引频次合计: 29 
摘要: We have theoretically and numerically investigated an analog of electromagnetically induced transparency (EIT) in plasmonic systems consisting of multiple cascaded nanodisk resonators, aperture-side-coupled to metal-insulator-metal bus waveguides. A simplified theoretical model is established to study spectral features in the plasmonic waveguide-resonator systems, and the calculated results are in good agreement with finite-difference time-domain simulations. The main dependent factors of EIT-like spectral response, namely, the resonance detuning, intrinsic Drude loss, and especially cavity-cavity separation, are discussed in detail. Similar to multiple EIT in quantum systems, multiple induced-transparency peaks are found in the areas of strong dispersion generated in our plasmonic system. The group indices and quality factors of transparency resonances with high transmission can reach levels of similar to 35 and similar to 200, respectively. These results pave a way toward dynamic control of light in the nanoscale domain, which can actualize some new devices for fundamental study and applications of plasmonic nanostructures.
文献类型: Article
KeyWords Plus: DROP FILTERS; METAL; RESONATORS; DEMULTIPLEXER; REFLECTION; POLARITON; OPTICS; CAVITY; CHIP
Web of Science 类别: Optics; Physics, Atomic, Molecular & Chemical
研究方向: Optics; Physics
IDS 号: 937HY 
ISSN: 1050-2947 

第 115 条，共 210 条
标题: Pulse Train from Graphene Solutions 
作者: Wang, J (Wang, Jin); Shu, C (Shu, Cheng); Fu, LL (Fu, Lili); Liu, CX (Liu, Chunxiao); Zhou, Y (Zhou, Yan); Wei, W (Wei, Wei); Peng, B (Peng, Bo)
来源出版物: ASIAN JOURNAL OF CHEMISTRY  卷: 24  期: 5  页: 2132-2134  出版年: MAY 2012  
Web of Science 核心合集中的 "被引频次": 0 
被引频次合计: 0 
摘要: We report on pulse train generation in an erbium-doped fiber laser with atomic layer graphene-water solutions which are fabricated from graphite by wet-chemistry techniques. Pulse trains generated from various concentration of graphene-water solutions are investigated under different laser energy. Present results show that atomic layer graphene-water solutions could be a promising saturable absorber for pulse trains due to its wavelength-independent ultrafast saturable absorption, good processbility and low cost.
文献类型: Article
作者关键词: Graphene solutions; Pulse train; Wet-chemistry techniques
KeyWords Plus: ATOMIC-LAYER GRAPHENE; SATURABLE ABSORBER; MODE-LOCKING; FIBER LASER; GRAPHITE; PHASE; EXFOLIATION; GAS
Web of Science 类别: Chemistry, Multidisciplinary
研究方向: Chemistry
IDS 号: 955PQ 
ISSN: 0970-7077 

第 116 条，共 210 条
标题: Design and characterization of a novel sensor combined imaging and zinc ion sensing 
作者: Wang, J (Wang, Jian); Wang, LL (Wang, Lili)
来源出版物: OPTICAL FIBER TECHNOLOGY  卷: 18  期: 3  页: 131-135  DOI: 10.1016/j.yofte.2012.02.003  出版年: MAY 2012  
Web of Science 核心合集中的 "被引频次": 1 
被引频次合计: 2 
摘要: A novel fluorescent sensor for Zn(II) detection and imaging is developed by incorporating 1-(2-pyridylazo)-2-naphthol (PAN) and Rhodamine B (RB) in a sol-gel film on an end face of a gradient index (GRIN) lens rod which is tightly connected with an imaging fiber. This technique has high-quality imaging capabilities for observing remote sample while measuring Zn(II). The RB and PAN employed in combination as the indicator for zinc-sensing is much cheaper than that of the other zinc-sensitive fluorescent dyes. The sol is prepared by base catalyzed hydrolysis of tetraethylorthosilicate (TEOS) with the addition of 3-glycidyloxypropyltrimethoxysilane (GLYMO) and 3-aminopropyltriethoxysilane (APTES), which is more suitable for Zn(II) detection. The sensor has the linear range of Zn(II) from 0.1 to 1 mmol/L. Simultaneously, it has the capabilities of real-time imaging with the whole system's resolution of 18.73 line pairs/mm. This bi-functional sensor has potential applications in in situ biosensing and other remote measurements. (C) 2012 Elsevier Inc. All rights reserved.
文献类型: Article
作者关键词: Fiber sensor; Fluorescence sensor; Imaging; Zinc ion
KeyWords Plus: GEL OPTICAL SENSOR; FLUORESCENT SENSORS; PHARMACEUTICALS; BIOSENSORS; PLATFORM; PROBES; FILMS
Web of Science 类别: Engineering, Electrical & Electronic; Optics; Telecommunications
研究方向: Engineering; Optics; Telecommunications
IDS 号: 941CF 
ISSN: 1068-5200 

第 117 条，共 210 条
标题: The Melioration on Spectra Response Heterogeneity of Hadamard Transform Spectral Imager 
作者: Liu, CF (Liu Cai-fang); Hu, BL (Hu Bing-liang); Wet, RY (Wet Ru-yi); Yan, P (Yan Peng)
来源出版物: SPECTROSCOPY AND SPECTRAL ANALYSIS  卷: 32  期: 5  页: 1427-1430  出版年: MAY 2012  
Web of Science 核心合集中的 "被引频次": 0 
被引频次合计: 0 
摘要: Hadamard transform optics has been developed in the past decades. It has been used in distinguishing targets, detecting feeble signals and so on. Hadamard transform spectral imager (HTSI), based on Digital Micro-Mirror Device, is a new dispersion spectral imager. HTSI has been developed in our laboratory. The spectral heterogeneity of encoded image captured by HTSI has been researched according to spectrum calibration in this paper. Relative and absolute spectrum emittance calibration algorithms have been proposed first time on HTSI to meliorate the spectrum heterogeneity. It aims at the problem that the accuracy of recovered spectrum is depressed by the heterogeneity noise and disorder encoding spectrum in spectral image. Simulation and experiment result have demonstrated that the meliorated spectral curve is close to the standard spectrum, and the variance of the recovered spectrum ranges from 2.4% to 4.2% with regard to the spectral image of 7 waves. This is fully satisfied for the requirement of laboratory and projects.
文献类型: Article
作者关键词: Hadamard transform; Heterogeneity melioration; Accuracy of recovered spectrum
Web of Science 类别: Spectroscopy
研究方向: Spectroscopy
IDS 号: 940NK 
ISSN: 1000-0593 

第 118 条，共 210 条
标题: Optical transmittance measurement system for coated elements with low transmittance 
作者: Wang, HY (Wang, Hongyun); Da, ZS (Da, Zhengshang); Liu, LL (Liu, Lili); Zhao, JN (Zhao, Juanning)
来源出版物: APPLIED OPTICS  卷: 51  期: 13  页: 2395-2399  DOI: 10.1364/AO.51.002395  出版年: MAY 1 2012  
Web of Science 核心合集中的 "被引频次": 0 
被引频次合计: 0 
摘要: The low-transmittance elements required for a high power laser facility have stringent specifications about transmittance. To validate optic performance against specifications, a metrology system for transmittance is proposed. The system is composed of a laser source, an integrating sphere, a power meter, and four uncoated wedged glasses. A relative measurement method is adopted, which is that the surface reflectivity of uncoated glass is used as the reference to compare with the sample's transmittance. The systematic feature is that uncoated wedged glasses are applied to split and reflect beams, which not only avoid coating errors, but also make the two beam powers attenuate properly. Measurement results for a sample's transmittance are presented. Experiment and analysis show that the relative standard uncertainty (sigma(T)/T) of measurement is 0.424%. This system is available for large-aperture elements. (c) 2012 Optical Society of America
PubMed ID: 22614417 
文献类型: Article
KeyWords Plus: NATIONAL-IGNITION-FACILITY; SPECTROPHOTOMETER; REFLECTANCE
Web of Science 类别: Optics
研究方向: Optics
IDS 号: 936UG 
ISSN: 1559-128X 
电子 ISSN: 2155-3165 

第 119 条，共 210 条
标题: Wavelength conversion, time demultiplexing and multicasting based on cross-phase modulation and four-wave mixing in dispersion-flattened highly nonlinear photonic crystal fiber 
作者: Hui, ZQ (Hui, Zhan-Qiang); Zhang, JG (Zhang, Jian-Guo)
来源出版物: JOURNAL OF OPTICS  卷: 14  期: 5  文献号: 055402  DOI: 10.1088/2040-8978/14/5/055402  出版年: MAY 2012  
Web of Science 核心合集中的 "被引频次": 4 
被引频次合计: 4 
摘要: We propose the use of cross-phase modulation (XPM) and four-wave mixing (FWM) in dispersion-flattened highly nonlinear photonic crystal fibers (HNL-PCFs) to implement the functionalities of wavelength conversion, simultaneous time demultiplexing and wavelength multicasting in optical time-division multiplexing (OTDM) systems. The experiments on wavelength conversion at 80 Gbit s(-1) and OTDM demultiplexing from 80 to 10 Gbit s(-1) with wavelength multicasting of two channels are successfully demonstrated to validate the proposed scheme, which are carried out by using two segments of dispersion-flattened HNL-PCFs with lengths of 100 and 50 m, respectively. Moreover, the bit error rate (BER) performance is also measured. The results show that our designed system can achieve a power penalty of less than 4.6 dB for two multicasting channels with a 24 nm wavelength span at the BER of 10(-9) when compared with the 10 Gbit/s back-to-back measurement. The proposed system is transparent to bit rate since only an ultrafast third-order nonlinear effect is used. The resulting configuration is compact, robust and reliable, benefiting from the use of dispersion-flattened HNL-PCFs with short lengths. This also makes the proposed system more flexible in the operational wavelengths than those based on dispersion-shifted fibers and traditional highly nonlinear fibers.
文献类型: Article
作者关键词: photonic crystal fiber; wavelength conversion; optical time-division multiplexing; multicasting; optical time demultiplexing; four-wave mixing
KeyWords Plus: OPTICAL-FIBER; ELECTROABSORPTION MODULATOR; LOOP MIRROR; 1.28 TBIT/S; SINGLE; TRANSMISSION; GB/S
Web of Science 类别: Optics
研究方向: Optics
IDS 号: 937GI 
ISSN: 2040-8978 

第 120 条，共 210 条
标题: Theoretical prediction of three-dimensional shifting of a spherical focal spot in a 4Pi focusing system 
作者: Li, Z (Li, Ze); Yan, SH (Yan, Shaohui); Yao, B (Yao, Baoli); Lei, M (Lei, Ming); Ma, BH (Ma, Baiheng); Gao, P (Gao, Peng); Dan, D (Dan, Dan); Rupp, R (Rupp, Romano)
来源出版物: JOURNAL OF OPTICS  卷: 14  期: 5  文献号: 055706  DOI: 10.1088/2040-8978/14/5/055706  出版年: MAY 2012  
Web of Science 核心合集中的 "被引频次": 0 
被引频次合计: 1 
摘要: A spherical focal spot can be generated by focusing radially polarized laser beams in a 4Pi focusing system, which will result in an increase in axial resolution in microscopy or higher axial trapping efficiency. We demonstrate the possibility of continuous shifting of the spherical focal spot along the prescribed trajectory in three-dimensional space by suitably modulating the phase of the input fields at the pupil planes of the microscope objective lenses. This may provide an alternative to moving trapped particles or scanning a specimen without moving either laser beams or the stage.
文献类型: Article
作者关键词: phase modulation; laser beam shaping; polarization
KeyWords Plus: RADIALLY POLARIZED BEAM; OPTICAL TWEEZERS; LASER-BEAM; FIELD; ILLUMINATION; MICROSCOPY; FORCES
Web of Science 类别: Optics
研究方向: Optics
IDS 号: 937GI 
ISSN: 2040-8978 

第 121 条，共 210 条
标题: Design of wideband, high-resolution optical waveform samplers based on a dispersion-flattened highly nonlinear photonic crystal fiber 
作者: Liu, YS (Liu, Yuanshan); Zhang, JG (Zhang, Jian-Guo); Zhao, W (Zhao, Wei)
来源出版物: JOURNAL OF OPTICS  卷: 14  期: 5  文献号: 055201  DOI: 10.1088/2040-8978/14/5/055201  出版年: MAY 2012  
Web of Science 核心合集中的 "被引频次": 1 
被引频次合计: 1 
摘要: A novel scheme is proposed for ultrafast optical waveform samplers capable of operating over a wide wavelength range, which uses the four-wave mixing in a highly nonlinear photonic crystal fiber (HNL-PCF) with low and very flat dispersion in the S, C and L bands. We report the first demonstration of the designed optical sampler by employing a 20 m dispersion-flattened HNL-PCF for observing the 160 Gbit s(-1) optical data signal to achieve a temporal resolution of less than 0.8 ps for a wavelength separation up to 11 nm between data signal and sampling lights. This preliminary result is mainly restricted by the tunable optical bandpass filter used in our present experiment. The proposed scheme shows a potential for realizing wideband, high-resolution optical waveform sampling systems in a simple configuration and a cost-effective manner by using commercially available optical fibers of short length.
文献类型: Article
作者关键词: all-optical sampling; photonic crystal fiber; four-wave mixing; ultrafast optical waveform samplers; optical fiber communications
KeyWords Plus: EYE-DIAGRAM MEASUREMENT; WAVELENGTH CONVERSION; SIGNAL; MODULATION; AMPLIFIER; RZ
Web of Science 类别: Optics
研究方向: Optics
IDS 号: 937GI 
ISSN: 2040-8978 

第 122 条，共 210 条
标题: Stable passively Q-switched operation of Tm3+ doped silica fiber laser by anti-resonant Fabry-Perot saturable absorber 
作者: Long, JY (Long, J. Y.); Shen, DY (Shen, D. Y.); Wang, YS (Wang, Y. Sh.); Zhao, W (Zhao, W.); An, Y (An, Y.); Zhou, W (Zhou, W.)
来源出版物: LASER PHYSICS  卷: 22  期: 5  页: 986-990  DOI: 10.1134/S1054660X12050209  出版年: MAY 2012  
Web of Science 核心合集中的 "被引频次": 0 
被引频次合计: 0 
摘要: We demonstrate a diode-pumped passively Q-switched Tm-doped double-cladding silica fiber laser operating at wavelength of 1960 nm using an anti-resonant Fabry-Perot saturable absorber as passive modulation element. To determine a relatively preferable fiber length for stable cw Q-switched operation, three active fiber simples with the length of 1.1, 5.3, and 7.0 m were employed respectively in our experiments. With 1.1 m gain fiber, we generated Q-switched pulses with a pulse width of 245 ns and an average power of up to 2.2 W at a repetition rate of 620 kHz. For the longer two fiber samples, Q-switched operation with longer pulse duration, Q-switched mode-locking and cw mode-locking were observed, respectively.
文献类型: Article
KeyWords Plus: 2 MU-M; PULSE-ENERGY; MICROCHIP LASERS; DYNAMICS
Web of Science 类别: Optics; Physics, Applied
研究方向: Optics; Physics
IDS 号: 940CW 
ISSN: 1054-660X 

第 123 条，共 210 条
标题: Gain spectrum of a laser-driven tripod-type atom dynamically induced in the presence of spontaneously generated coherence 
作者: Tian, SC (Tian, Si-Cong); Wan, RG (Wan, Ren-Gang); Kang, ZH (Kang, Zhi-Hui); Zhang, H (Zhang, Hang); Jiang, Y (Jiang, Yun); Cui, HN (Cui, Hai-Ning); Gao, JY (Gao, Jin-Yue)
来源出版物: JOURNAL OF THE OPTICAL SOCIETY OF AMERICA B-OPTICAL PHYSICS  卷: 29  期: 5  页: 881-890  出版年: MAY 1 2012  
Web of Science 核心合集中的 "被引频次": 1 
被引频次合计: 1 
摘要: We examine the absorption of a weak probe beam in a laser-driven tripod-type atom with three closely lying ground levels, where both the driving and probe lasers interact simultaneously with the three transitions. The effects of spontaneously generated coherence (SGC) are taken into account. We introduce dipole moments in the dressed-state picture and the Hamiltonian in terms of the dressed states describing the interaction between the probe and the atom. Gain spectrum under various conditions are presented and analyzed. We show that the spectral structure and the gain amplitude of the probe are strongly influenced by the effect of SGC and the frequency separation of the three closely lying ground levels. The tripod-type atomic system with quantum interference in spontaneous emission can be simulated in the dressed-state picture of a coherently driven four-level N-type system where no SGC effect exists. (C) 2012 Optical Society of America
文献类型: Article
KeyWords Plus: ABSORPTION; INTERFERENCE; SYSTEM; TRANSPARENCY; EMISSION
Web of Science 类别: Optics
研究方向: Optics
IDS 号: 935TN 
ISSN: 0740-3224 

第 124 条，共 210 条
标题: Monomode Optical Waveguides in Yb3+-Doped Silicate Glasses Produced by Low-Dose Carbon Ion Implantation 
作者: Liu, CX (Liu, Chun-Xiao); Cheng, S (Cheng, Shu); Li, WN (Li, Wei-Nan); Wei, W (Wei, Wei); Peng, B (Peng, Bo)
来源出版物: JAPANESE JOURNAL OF APPLIED PHYSICS  卷: 51  期: 5  文献号: 052601  DOI: 10.1143/JJAP.51.052601  子辑: 1  出版年: MAY 2012  
Web of Science 核心合集中的 "被引频次": 2 
被引频次合计: 2 
摘要: The planar waveguide has been fabricated in the Yb3+-doped silicate glass by 4.0 MeV C2+ ion implantation at a dose of 2 x 10(14) ions/cm(2). The guided modes are measured using a model 2010 prism coupler at 633 nm. The near-field profiles of the planar waveguide are obtained with an end-face coupling system. The refractive index profile of the waveguide is reconstructed by the intensity calculation method, which shows a typical "enhanced well + barrier" distribution. The SRIM'2006 code is carried out to simulate the energy loss during the implantation in order to obtain a better understanding of the waveguide formation. After post-implantation treatment at 260 degrees C for 1 h, the waveguide possesses a propagation loss of similar to 1.42 dB/cm. The acceptable guiding properties suggest that further waveguide lasers may be realized on the C-implanted Yb3+-doped silicate glass waveguides. (C) 2012 The Japan Society of Applied Physics
文献类型: Article
KeyWords Plus: REFRACTIVE-INDEX PROFILES; PHOSPHATE-GLASS; LITHIUM-NIOBATE; LASER
Web of Science 类别: Physics, Applied
研究方向: Physics
IDS 号: 940YY 
ISSN: 0021-4922 
电子 ISSN: 1347-4065 

第 125 条，共 210 条
标题: Design and analysis of a novel noncollinear acousto-optic tunable filter 
作者: Zhu, YY (Zhu, Yingying); Zhang, CM (Zhang, Chunmin); Zhao, BC (Zhao, Baochang)
来源出版物: OPTICS COMMUNICATIONS  卷: 285  期: 9  页: 2332-2334  DOI: 10.1016/j.optcom.2012.01.027  出版年: MAY 1 2012  
Web of Science 核心合集中的 "被引频次": 4 
被引频次合计: 5 
摘要: The design of a noncollinear acousto-optic tunable filter (AOTF) is commonly based on parallel tangent momentum-matching condition. Previous studies have either moving parts or modulation. These approaches would obviously decrease the accuracy of an acousto-optic tunable filter (AOTF) since it will be influenced by vibration or by an extended measurement time. In this paper, we introduce a novel noncollinear acousto-optic tunable filter division-of-amplitude photopolarimeter (DOAP). It is completely characterized by a wavelength-dependent 4 x 4 matrix that can be determined directly by calibration. The instrument has neither moving parts nor modulation. Besides, this system can acquire the image, spectral and polarization information of an object simultaneously. (C) 2012 Elsevier B.V. All rights reserved.
文献类型: Article
作者关键词: Acousto-optic tunable filter; Image; Spectral and polarization information
KeyWords Plus: DIFFRACTION
Web of Science 类别: Optics
研究方向: Optics
IDS 号: 915QM 
ISSN: 0030-4018 

第 126 条，共 210 条
标题: Shadow detection for color remotely sensed images based on multi-feature integration 
作者: Liu, JH (Liu, Jiahang); Li, DR (Li, Deren); Fang, T (Fang, Tao)
来源出版物: JOURNAL OF APPLIED REMOTE SENSING  卷: 6  文献号: 063521  DOI: 10.1117/1.JRS.6.063521  出版年: APR 23 2012  
Web of Science 核心合集中的 "被引频次": 1 
被引频次合计: 1 
摘要: A novel shadow detection method for color remotely sensed images that satisfies requirements for both high accuracy and wide adaptability in applications is presented. This method builds on previously reported work investigating the shadow properties in both red/green/blue (RGB) and hue saturation value (HSV) color spaces. The method integrates several shadow features for modeling and uses a region growing (RG) algorithm and a perception machine (PM) of a neural network (NN) to identify shadows. To ensure efficiency of the parameters, first the proposed method uses a small number of shadow samples manually obtained from an input image to automatically estimate the necessary parameters. Then, the method uses the estimated threshold to binarize the hue map of the input image for obtaining possible shadow seeds and applies the RG algorithm to produce a candidate shadow map from the intensity channel. Subsequently, all of the hue, saturation, and intensity maps from the candidate shadow map are filtered with a corresponding band-pass filter, and the filtered results are input into the PM algorithm for the final shadow segmentation. Experiments indicate that the proposed algorithm has better performance in multiple cases, providing a new and practical shadow detection method. (C) 2012 Society of Photo-Optical Instrumentation Engineers (SPIE). [DOI: 10.1117/1.JRS.6.063521]
文献类型: Article
作者关键词: shadow detection; multi-feature integration; image segmentation; color remotely sensed images; perception machine
KeyWords Plus: AERIAL IMAGES; BUILDINGS
Web of Science 类别: Environmental Sciences; Remote Sensing; Imaging Science & Photographic Technology
研究方向: Environmental Sciences & Ecology; Remote Sensing; Imaging Science & Photographic Technology
IDS 号: 942HV 
ISSN: 1931-3195 

第 127 条，共 210 条
标题: Scale invariant image matching using triplewise constraint and weighted voting 
作者: Pang, YW (Pang, Yanwei); Shang, MY (Shang, Mianyou); Yuan, Y (Yuan, Yuan); Pan, J (Pan, Jing)
来源出版物: NEUROCOMPUTING  卷: 83  页: 64-71  DOI: 10.1016/j.neucom.2011.11.008  出版年: APR 15 2012  
Web of Science 核心合集中的 "被引频次": 14 
被引频次合计: 14 
摘要: Due to limited computational resource, image matching on mobile phone places great demand on efficiency and scale invariant. Though spectral matching (SM) with pairwisely geometric constraints is widely used in matching, it is not efficient and scale invariant for applications in mobile phones. The main factor that limits its efficiency is that it requires to eign-decomposition of a large affinity matrix when the number of candidate correspondences is large. It lacks scale invariance because the pairwise constraints cannot hold when large scale variation occurs. In this paper, we attempt to tackle these problems. In the proposed method, each candidate correspondence is considered as a voter and a candidate as well. As a voter it gives voting scores to other candidates and also votes itself. Based on the voting scores, the optimal correspondences are computed by simple addition operations and ranking operations, which results in high efficiency. To make the proposed method scale invariant, we propose a novel triple-wisely geometric constraint formed by three potential correspondences with one being the candidate and the other two being voters. The three correspondences constitute a pair of triangles. The similarity of the two triangles is the core of the triple-wisely constraint, which is robust to scale variation. The information of triple-wise constraints are encoded in a 3-dimensional matrix from which the optimal correspondence can be obtained by simple summation and ranking operations. Experimental results on real-data show the effectiveness and efficiency of the proposed method. (C) 2012 Elsevier B.V. All rights reserved.
文献类型: Article
作者关键词: Image matching; Spectral technique; Correspondence establishment; Weighted voting
KeyWords Plus: RELEVANCE FEEDBACK; SUBSPACE
Web of Science 类别: Computer Science, Artificial Intelligence
研究方向: Computer Science
IDS 号: 910CC 
ISSN: 0925-2312 

第 128 条，共 210 条
标题: Similarity learning for object recognition based on derived kernel 
作者: Li, H (Li, Hong); Wei, YT (Wei, Yantao); Li, LQ (Li, Luoqing); Yuan, Y (Yuan, Yuan)
来源出版物: NEUROCOMPUTING  卷: 83  页: 110-120  DOI: 10.1016/j.neucom.2011.12.005  出版年: APR 15 2012  
Web of Science 核心合集中的 "被引频次": 6 
被引频次合计: 6 
摘要: Recently, derived kernel method which is a hierarchical learning method and leads to an effective similarity measure has been proposed by Smale. It can be used in a variety of application domains such as object recognition, text categorization and classification of genomic data. The templates involved in the construction of the derived kernel play an important role. To learn more effective similarity measure, a new template selection method is proposed in this paper. In this method, the redundancy is reduced and the label information of the training images is used. In this way, the proposed method can obtain compact template sets with better discrimination ability. Experiments on four standard databases show that the derived kernel based on the proposed method achieves high accuracy with low computational complexity. (C) 2012 Elsevier B.V. All rights reserved.
文献类型: Article
作者关键词: Derived kernel; Hierarchical learning; Image similarity; Neural response; Object recognition; Template selection
KeyWords Plus: FACE RECOGNITION; IMAGE SIMILARITY; CORTEX; DECOMPOSITION; DISTANCE; FEATURES
Web of Science 类别: Computer Science, Artificial Intelligence
研究方向: Computer Science
IDS 号: 910CC 
ISSN: 0925-2312 

第 129 条，共 210 条
标题: Synthesis of a soluble polythiophene copolymer with thiophene-vinylene conjugated side chain and its applications in photovoltaic devices 
作者: Qu, B (Qu, Bo); Jiang, ZL (Jiang, Zhongliang); Chen, ZJ (Chen, Zhijian); Xiao, LX (Xiao, Lixin); Tian, D (Tian, Di); Gao, C (Gao, Chao); Wei, W (Wei, Wei); Gong, QH (Gong, Qihuang)
来源出版物: JOURNAL OF APPLIED POLYMER SCIENCE  卷: 124  期: 2  页: 1186-1192  DOI: 10.1002/app.35078  出版年: APR 15 2012  
Web of Science 核心合集中的 "被引频次": 4 
被引频次合计: 4 
摘要: A new soluble polythiophene copolymer with thiophene-vinylene conjugated side chain poly[3-(5'-octylthienylenevinyl) thiophene]-thiophene (POTVTh-Th) was successfully synthesized and characterized using NMR, UV-visible spectroscopy, etc. To study the photovoltaic property of the copolymer, photovoltaic device of ITO/PEDOT:PSS/POTVTh-Th:[6,6]-phenyl C61-butyric acid methyl ester (PC61BM) (weight ratio being 1 : 1)/LiF/Al was fabricated, in which POTVTh-Th acted as the electron donor in the active layer. Under 100 mW/cm(2) AM 1.5G simulated solar emission, the open-circuit voltage and the short-circuit current density of the device were 0.58 V and 2.50 mA/cm(2), respectively. The power conversion efficiency and the fill factor of the photovoltaic device were evaluated to be 0.42% and 0.30. (C) 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
文献类型: Article
作者关键词: polythiophene; polymers; organic photovoltaic devices; solar cells; bulk-heterojunction
KeyWords Plus: POLYMER
Web of Science 类别: Polymer Science
研究方向: Polymer Science
IDS 号: 870MF 
ISSN: 0021-8995 

第 130 条，共 210 条
标题: Collimating lens for light-emitting-diode light source based on non-imaging optics 
作者: Wang, GZ (Wang, Guangzhen); Wang, LL (Wang, Lili); Li, FL (Li, Fuli); Zhang, GJ (Zhang, Gongjian)
来源出版物: APPLIED OPTICS  卷: 51  期: 11  页: 1654-1659  DOI: 10.1364/AO.51.001654  出版年: APR 10 2012  
Web of Science 核心合集中的 "被引频次": 5 
被引频次合计: 7 
摘要: A collimating lens for a light-emitting-diode (LED) light source is an essential device widely used in lighting engineering. Lens surfaces are calculated by geometrical optics and nonimaging optics. This design progress does not rely on any software optimization and any complex iterative process. This method can be used for any type of light source not only Lambertian. The theoretical model is based on point source. But the practical LED source has a certain size. So in the simulation, an LED chip whose size is 1 mm * 1 mm is used to verify the feasibility of the model. The mean results show that the lenses have a very compact structure and good collimating performance. Efficiency is defined as the ratio of the flux in the illuminated plane to the flux from LED source without considering the lens material transmission. Just investigating the loss in the designed lens surfaces, the two types of lenses have high efficiencies of more than 90% and 99%, respectively. Most lighting area (possessing 80% flux) radii are no more than 5 m when the illuminated plane is 200 m away from the light source. (C) 2012 Optical Society of America
PubMed ID: 22505154 
文献类型: Article
KeyWords Plus: DESIGN; REGION
Web of Science 类别: Optics
研究方向: Optics
IDS 号: 926VR 
ISSN: 1559-128X 
电子 ISSN: 2155-3165 

第 131 条，共 210 条
标题: Efficient terahertz-wave generation via four-wave mixing in silicon membrane waveguides 
作者: Wang, ZL (Wang, Zhaolu); Liu, HJ (Liu, Hongjun); Huang, N (Huang, Nan); Sun, QB (Sun, Qibing); Wen, J (Wen, Jin)
来源出版物: OPTICS EXPRESS  卷: 20  期: 8  页: 8920-8928  DOI: 10.1364/OE.20.008920  出版年: APR 9 2012  
Web of Science 核心合集中的 "被引频次": 7 
被引频次合计: 8 
摘要: Terahertz (THz) wave generation via four-wave mixing (FWM) in silicon membrane waveguides is theoretically investigated with mid-infrared laser pulses. Compared with the conventional parametric amplification or wavelength conversion based on FWM in silicon waveguides, which needs a pump wavelength located in the anomalous group-velocity dispersion (GVD) regime to realize broad phase matching, the pump wavelength located in the normal GVD regime is required to realize collinear phase matching for the THz-wave generation via FWM. The pump wavelength and rib height of the silicon membrane waveguide can be tuned to obtain a broadband phase matching. Moreover, the conversion efficiency of the THz-wave generation is studied with different pump wavelengths and rib heights of the silicon membrane waveguides, and broadband THz-wave can be obtained with high efficiency exceeding 1%. (C) 2012 Optical Society of America
PubMed ID: 22513603 
文献类型: Article
KeyWords Plus: DIFFERENCE-FREQUENCY-GENERATION; POLED LITHIUM-NIOBATE; PARAMETRIC GENERATION; WAVELENGTH CONVERSION; STRAINED SILICON; CONFIGURATION; OSCILLATION
Web of Science 类别: Optics
研究方向: Optics
IDS 号: 926TT 
ISSN: 1094-4087 

第 132 条，共 210 条
标题: Q-switched mode-locking and dissipative soliton operations in a large-anomalous-dispersion fiber laser 
作者: Han, DD (Han, Dongdong); Yun, L (Yun, Ling)
来源出版物: OPTICAL ENGINEERING  卷: 51  期: 4  文献号: 044201  DOI: 10.1117/1.OE.51.4.044201  出版年: APR 2012  
Web of Science 核心合集中的 "被引频次": 2 
被引频次合计: 2 
摘要: We have experimentally observed the Q-switched mode-locking (QML) and dissipative soliton operations in the passively mode-locked fiber laser operating in large-anomalous-dispersion regime. With the increase of pump power, the proposed fiber laser gradually evolves from continuous-wave to QML and finally to dissipative soliton operations. The transition state between QML and dissipative solitons has been observed. The experimental results suggest that the fiber laser based on the nonlinear polarization rotation technique exhibits Q-switching instabilities. (C) 2012 Society of Photo-Optical Instrumentation Engineers (SPIE). [DOI: 10.1117/1.OE.51.4.044201]
文献类型: Article
作者关键词: fiber laser; anomalous dispersion; Q-switched mode-locking; dissipative soliton
KeyWords Plus: ERBIUM-DOPED FIBER; NONLINEAR POLARIZATION ROTATION; RING LASER; ENERGY; PULSES; RESONANCE; GENERATION; SESAM
Web of Science 类别: Optics
研究方向: Optics
IDS 号: 942BS 
ISSN: 0091-3286 

第 133 条，共 210 条
标题: Theoretical analysis on scanning spectral filter method for signal-noise-ratio improvment in femtosecond laser system 
作者: Ma, AR (Ma Aai-Ru); Sui, Z (Sui Zhan); Feng, GY (Feng Guo-Ying); Sun, NC (Sun Nian-Chun); Wang, YS (Wang Yi-Shan); Zhang, B (Zhang Bin); Chen, JG (Chen Jian-Guo)
来源出版物: ACTA PHYSICA SINICA  卷: 61  期: 7  文献号: 074206  出版年: APR 2012  
Web of Science 核心合集中的 "被引频次": 0 
被引频次合计: 0 
摘要: A scanning spectral filter method to improve the signal-noise-ratio in the femtosecond chains is proposed by using the characteristic that the instantaneous frequency varies with the time approximately linearly for the chirped pulse in the time-frequency domain. The scanning spectral filtering for reduing the amplification of spontaneous emission (ASE) intensity is analyzed in the time-frequency domain by using the Short-Time Fourier Transform method. The results show that the pulse contrast can be improved by two orders, and the transmission efficiency of the chirped pulse can exceed 90% when the synchronizing time jitter ranges from -2ps to 2ps and the chirp rate p from 0.9C/T-2 to 1.10C/T-2. Adopting the cascaded scanning filter to improve the pulse contrast is investigated too, which can improve the pulse contrast effectively. The great advantage of this novel nonlinear spectral filter technology is high energy and high peak intensity femtosecond chains for it filters out the ASE in the near field in temporal domain.
文献类型: Article
作者关键词: ultrafast optics; ultrafast technology; spectral scanning filtering; short time fourier transform
KeyWords Plus: CHIRPED-PULSE AMPLIFICATION; HIGH-CONTRAST; HIGH-ENERGY; GENERATION; PROPAGATION; ENHANCEMENT; W/CM(2); SCHEME; OPCPA
Web of Science 类别: Physics, Multidisciplinary
研究方向: Physics
IDS 号: 928YX 
ISSN: 1000-3290 

第 134 条，共 210 条
标题: Phases in a General Chaotic Three-Coupled-Laser Array 
作者: Zhou, L (Zhou Liang); Duan, KL (Duan Kai-Liang)
来源出版物: CHINESE PHYSICS LETTERS  卷: 29  期: 4  文献号: 044201  DOI: 10.1088/0256-307X/29/4/044201  出版年: APR 2012  
Web of Science 核心合集中的 "被引频次": 0 
被引频次合计: 0 
摘要: Phases in a general chaotic three-coupled-laser array are numerically investigated. Phase attractors are firstly found to exist within corresponding basins of attraction on the projection plane of phase differences of the three-coupled-laser array. Whether the chaos appears or not is related not only to the coupling strength but also to the initial phase differences. For a large coupling strength new phase attractors can occur. With the increase of coupling strength, the three-coupled-laser array has a great chance of resulting in a quiescent to chaotic state. Based on these results, we present the method to reach phase-locking when the coupling strength is strong.
文献类型: Article
KeyWords Plus: COUPLED LASERS; SYNCHRONIZATION; COHERENCE; DYNAMICS
Web of Science 类别: Physics, Multidisciplinary
研究方向: Physics
IDS 号: 927AM 
ISSN: 0256-307X 

第 135 条，共 210 条
标题: Generation and Propagation of Bound-State Pulses in a Passively Mode-Locked Figure-Eight Laser 
作者: Yun, L (Yun, Ling); Liu, XM (Liu, Xueming)
来源出版物: IEEE PHOTONICS JOURNAL  卷: 4  期: 2  页: 512-519  DOI: 10.1109/JPHOT.2012.2191948  出版年: APR 2012  
Web of Science 核心合集中的 "被引频次": 18 
被引频次合计: 19 
摘要: We have investigated the generation and propagation of robust bound-state pulses emitted from a passively mode-locked figure-eight laser with net-anomalous dispersion. Two pulses with the pulse duration of similar to 1.3 ps and the separation of similar to 2.2 ps exhibit a strongly modulated spectral profile. The experimental observations show that the pulse duration and the separation increase approximately linearly along the extracavity single-mode fiber (SMF). The pulse duration and separation are broadened by a factor of similar to 7 and similar to 5.7, respectively, after the pulse pair propagates through the standard SMF of 202 m. The theoretical results well agree with the experimental observations.
文献类型: Article
作者关键词: Fiber optics systems; erbium lasers; ultrashort pulse; pulse propagation
KeyWords Plus: DISSIPATIVE SOLITON RESONANCE; NET-NORMAL-DISPERSION; ERBIUM-DOPED FIBER; PAIRS
Web of Science 类别: Engineering, Electrical & Electronic; Optics; Physics, Applied
研究方向: Engineering; Optics; Physics
IDS 号: 925EM 
ISSN: 1943-0655 

第 136 条，共 210 条
标题: Autofocusing based on wavelength dependence of diffraction in two-wavelength digital holographic microscopy 
作者: Gao, P (Gao, Peng); Yao, BL (Yao, Baoli); Rupp, R (Rupp, Romano); Min, JW (Min, Junwei); Guo, RL (Guo, Rongli); Ma, BH (Ma, Baiheng); Zheng, JJ (Zheng, Juanjuan); Lei, M (Lei, Ming); Yan, SH (Yan, Shaohui); Dan, D (Dan, Dan); Ye, T (Ye, Tong)
来源出版物: OPTICS LETTERS  卷: 37  期: 7  页: 1172-1174  出版年: APR 1 2012  
Web of Science 核心合集中的 "被引频次": 10 
被引频次合计: 10 
摘要: An autofocusing method for two-wavelength digital holographic microscopy (TWDHM) based on the wavelength dependence of the diffraction process is proposed. Red and green lights are employed for the illumination of the TWDHM, and the generated holograms are recorded simultaneously by a color CCD camera. Due to the wavelength dependency of the diffraction process, the farther the reconstruction plane is from the image plane, the larger the difference is between the red and green light distributions. Thus, the image plane can be determined by finding the minimum of the variation between the red and green lights on their amplitude distributions. The feasibility of the proposed method is demonstrated by simulation and experiment. (C) 2012 Optical Society of America
PubMed ID: 22466185 
文献类型: Article
KeyWords Plus: QUANTITATIVE PHASE MICROSCOPY; REAL-TIME; NUMERICAL RECONSTRUCTION; FRESNEL HOLOGRAMS; OBJECTS; IMAGE; FIELD
Web of Science 类别: Optics
研究方向: Optics
IDS 号: 925NP 
ISSN: 0146-9592 

第 137 条，共 210 条
标题: Yb3+ doped fluorophosphate laser glasses with high gain coefficient and improved laser property 
作者: Wang, PF (Wang, P. F.); Peng, B (Peng, B.); Li, WN (Li, W. N.); Hou, CQ (Hou, Ch. Q.); She, JB (She, J. B.); Guo, HT (Guo, H. T.); Lu, M (Lu, M.)
来源出版物: SOLID STATE SCIENCES  卷: 14  期: 4  页: 550-553  DOI: 10.1016/j.solidstatesciences.2011.12.004  出版年: APR 2012  
Web of Science 核心合集中的 "被引频次": 6 
被引频次合计: 6 
摘要: Yb3+ doped fluorophosphate glasses with high stimulated emission cross-section, large gain coefficient and low hydroxyl absorption coefficient were prepared by high temperature melting for fiber laser applications, and their spectral, general laser parameters were investigated accordingly by means of fluorescence emission spectrum, decay cure and infrared absorption spectra. Compared with previously reported fluorophosphate glasses, the investigated fluorophosphate glasses have highest grain coefficient and maintain a maximum laser systematical factor over other various types of laser glasses. The introduction of fluorides to fluorophosphate glasses results in the low level of hydroxyl absorption coefficient and concentration. All these advantages might mean that Yb3+ doped fluorophosphate glasses are a good candidate as an active laser media for short pulse, high power laser generation used for next generation nuclear fusion. (C) 2011 Elsevier Masson SAS. All rights reserved.
文献类型: Article
作者关键词: Fluorophosphate laser glasses; High gain coefficient; Laser property; Hydroxyl absorption coefficient
KeyWords Plus: EMISSION CROSS-SECTION; RARE-EARTH IONS; TELLURITE; YTTERBIUM; SPECTRA; WATER
Web of Science 类别: Chemistry, Inorganic & Nuclear; Chemistry, Physical; Physics, Condensed Matter
研究方向: Chemistry; Physics
IDS 号: 929TB 
ISSN: 1293-2558 

第 138 条，共 210 条
标题: Research on the Method of Transient Spectrum Detection Based on Array CCD 
作者: Zhu, BL (Zhu Bing-li); Bai, YL (Bai Yong-lin); Wang, B (Wang Bo); Liu, BY (Liu Bai-yu); Ouyang, X (Ouyang Xian); Yang, WZ (Yang Wen-zheng); Bai, XH (Bai Xiao-hong); Qin, JJ (Qin Jun-jun); Zhao, JP (Zhao Jun-ping); Gou, YS (Gou Yong-sheng); Lu, K (Lu Kai)
来源出版物: SPECTROSCOPY AND SPECTRAL ANALYSIS  卷: 32  期: 4  页: 1028-1031  DOI: 10.3964/j.issn.1000-0593(2012)04-1028-04  出版年: APR 2012  
Web of Science 核心合集中的 "被引频次": 0 
被引频次合计: 1 
摘要: Based on the characteristic of high speed line scanning for CCD in transient spectrum detection, a method of transient spectrum detection with array CCD is presented. The high speed line scanning with array CCD was realized by changing the mode of charge transfer. In order to explore the feasibility of this method, a fast detection system of single point based on linear CCD was designed and fabricated. Seven different LED pulses were measured when the system worked at fast detection mode of single point and normal mode respectively. The results demonstrate that the method of fast detection of single point based on linear CCD is feasible, and the rate of single point detection reaches up to 20 MHz. Thus, in theory, it was proved that transient spectrum detection with array CCD by changing the mode of charge transfer is also feasible.
文献类型: Article
作者关键词: Linear CCD; Array CCD; CCD high speed imaging; Transient spectrum detection
Web of Science 类别: Spectroscopy
研究方向: Spectroscopy
IDS 号: 921AI 
ISSN: 1000-0593 

第 139 条，共 210 条
标题: Synthesis and Optical Properties of Nd(III) Perfluoro-Carboxylate Complexes with 2,2 '-Bipyridine 
作者: She, JB (She Jiang-bo); Li, DD (Li Dong-dong); Wang, PF (Wang Peng-fei); Zhu, YG (Zhu Yong-gang); Wei, W (Wei Wei); Peng, B (Peng Bo)
来源出版物: SPECTROSCOPY AND SPECTRAL ANALYSIS  卷: 32  期: 4  页: 1047-1050  DOI: 10.3964/j.issn.1000-0593(2012)04-1047-04  出版年: APR 2012  
Web of Science 核心合集中的 "被引频次": 0 
被引频次合计: 1 
摘要: A series of neodymium complexes, Nd(CF3COO)(3) center dot Dipy, Nd(C2F5COO)(3) center dot Dipy and Nd(C3F7COO)(3) center dot Dipy were synthesized and characterized by FTIR spectra, elemental analysis, thermogravimetric analysis, UV-Vis-NIR absorption spectra and PL spectra. The decomposition temperature was found to be more than 260 degrees C and maximum weight losses rates above 340 degrees C which indicate that they have good thermal stability. The low vibrational energy C-F bonds were used to replace the C-H bonds in organic group for improving the optical properties of materials. The length of carbon chain and the coordination structure of Nd(III) affect the absorption transition strength. According to the UV-Vis-NIR absorption spectra, the Judd-Ofelt parameters were calculated and the radiative properties were also presented. The stimulated emission cross-sections of the Nd(CF3COO)(3) center dot Dipy, Nd(C2F5COO)(3) center dot Dipy and Nd(C3F7COO)(3) center dot Dipy were 3. 63 X 10(-20), 2. 36 X 10(-20) and 1.49 X 10(-20) cm(2) respectively, which were as good as some reported inorganic materials. These complexes will be a series of promising materials for liquid laser application.
文献类型: Article
作者关键词: Neodymium complex; Liquid laser; Judd-Ofelt theory; Stimulated emission cross-sections
KeyWords Plus: NEODYMIUM; LASER; ND3+; IONS
Web of Science 类别: Spectroscopy
研究方向: Spectroscopy
IDS 号: 921AI 
ISSN: 1000-0593 

第 140 条，共 210 条
标题: Robust CoHOG Feature Extraction in Human-Centered Image/Video Management System 
作者: Pang, YW (Pang, Yanwei); Yan, H (Yan, He); Yuan, Y (Yuan, Yuan); Wang, KQ (Wang, Kongqiao)
来源出版物: IEEE TRANSACTIONS ON SYSTEMS MAN AND CYBERNETICS PART B-CYBERNETICS  卷: 42  期: 2  特刊: SI  页: 458-468  DOI: 10.1109/TSMCB.2011.2167750  出版年: APR 2012  
Web of Science 核心合集中的 "被引频次": 20 
被引频次合计: 22 
摘要: Many human-centered image and video management systems depend on robust human detection. To extract robust features for human detection, this paper investigates the following shortcomings of co-occurrence histograms of oriented gradients (CoHOGs) which significantly limit its advantages: 1) The magnitudes of the gradients are discarded, and only the orientations are used; 2) the gradients are not smoothed, and thus, aliasing effect exists; and 3) the dimensionality of the CoHOG feature vector is very large (e.g., 200 000). To deal with these problems, in this paper, we propose a framework that performs the following: 1) utilizes a novel gradient decomposition and combination strategy to make full use of the information of gradients; (2) adopts a two-stage gradient smoothing scheme to perform efficient gradient interpolation; and (3) employs incremental principal component analysis to reduce the large dimensionality of the CoHOG features. Experimental results on the two different human databases demonstrate the effectiveness of the proposed method.
PubMed ID: 22113786 
文献类型: Article
作者关键词: Co-occurrence histograms of oriented gradients (CoHOGs); histograms of oriented gradients (HOGs); human-centered image retrieval; human detection
KeyWords Plus: SUPPORT VECTOR MACHINES; PEDESTRIAN DETECTION; IMAGE RETRIEVAL; RECOGNITION; SEGMENTATION; SURVEILLANCE; SUBSPACE
Web of Science 类别: Automation & Control Systems; Computer Science, Artificial Intelligence; Computer Science, Cybernetics
研究方向: Automation & Control Systems; Computer Science
IDS 号: 916JC 
ISSN: 1083-4419 

第 141 条，共 210 条
标题: Application of terahertz spectroscopy and molecular modeling in isomers investigation: Glucose and fructose 
作者: Zheng, ZP (Zheng, Zhuan-Ping); Fan, WH (Fan, Wen-Hui); Liang, YQ (Liang, Yu-Qing); Yan, H (Yan, Hui)
来源出版物: OPTICS COMMUNICATIONS  卷: 285  期: 7  页: 1868-1871  DOI: 10.1016/j.optcom.2011.12.016  出版年: APR 1 2012  
Web of Science 核心合集中的 "被引频次": 4 
被引频次合计: 5 
摘要: Terahertz spectra of glucose and fructose have been measured by terahertz time-domain spectroscopy (THz-TDS) at room temperature. Because they have the same molecular formula, the differences of the THz spectra can be attributed to their molecular structures and the arrangement of molecules in unit cell In this paper, gaseous-state theory has been employed to simulate the isolated molecule of these two isomers. The results indicate that experimental THz spectral features (0.5-4.0 THz) of glucose and fructose arise from the mixture of intramolecular and intermolecular modes, involving hydrogen bonds and covalent bonds, and with the intermolecular modes dominating. (C) 2011 Elsevier B.V. All rights reserved.
文献类型: Article
作者关键词: THz-TDS; Glucose; Fructose
KeyWords Plus: TIME-DOMAIN SPECTROSCOPY; DENSITY-FUNCTIONAL THEORY; COMPONENT ANALYSIS; VIBRATIONAL-MODES; AB-INITIO; EXPLOSIVES
Web of Science 类别: Optics
研究方向: Optics
IDS 号: 902JW 
ISSN: 0030-4018 

第 142 条，共 210 条
标题: Bragg gap solitons in PT symmetric lattices with competing nonlinearity 
作者: Liu, S (Liu, Shuang); Ma, CW (Ma, Caiwen); Zhang, YQ (Zhang, Yiqi); Lu, KQ (Lu, Keqing)
来源出版物: OPTICS COMMUNICATIONS  卷: 285  期: 7  页: 1934-1939  DOI: 10.1016/j.optcom.2011.11.065  出版年: APR 1 2012  
Web of Science 核心合集中的 "被引频次": 8 
被引频次合计: 8 
摘要: The effect of competing nonlinearity on beam dynamics in parity-time (PT) symmetric potentials is investigated. By using numerical methods, the existence of gap solitons is demonstrated in the first Bragg band gap of optical (PT) symmetric lattices with competing nonlinearity. Meanwhile, the stability of such solitons is analyzed through introducing a small perturbation to the solitary solutions. The abrupt annihilation of the solitons during propagation demonstrates that the Bragg gap solitons in PT symmetric potentials are not stable. In comparison with the on-site gap solitons, the off-site gap solitons exhibit more robust properties during propagation. (C) 2011 Elsevier B.V. All rights reserved.
文献类型: Article
作者关键词: Gap solitons; PT symmetry; Competing Nonlinearity
KeyWords Plus: POTENTIALS; OPTICS
Web of Science 类别: Optics
研究方向: Optics
IDS 号: 902JW 
ISSN: 0030-4018 

第 143 条，共 210 条
标题: Characteristics of pulse evolution in mode-locked thulium-doped fiber laser 
作者: An, Y (An, Ying); Shen, DY (Shen, Deyuan); Zhao, W (Zhao, Wei); Long, JY (Long, Jingyu)
来源出版物: OPTICS COMMUNICATIONS  卷: 285  期: 7  页: 1949-1953  DOI: 10.1016/j.optcom.2011.12.001  出版年: APR 1 2012  
Web of Science 核心合集中的 "被引频次": 2 
被引频次合计: 2 
摘要: We have numerically investigated the characteristics of the pulse evolution in a passively mode-locked thulium-doped fiber laser with net anomalous cavity dispersion. For the fixed resonator configuration, single-, dual-, triple-, and quadruple-pulses are generated successively by enhancing the pump power or reducing the output ratio. The characteristics of the single or multiple pulses are investigated with various cavity lengths. The separation between the two coexisting pulses changes with the pump power due to the interaction between the soliton and the dispersive waves, and then the two randomly distributed pulses could finally evolve into a soliton pair with fixed separation. According to the results of the numerical simulation, the multiple pulses are found to be generated via pulse splitting and the pulse splitting threshold decreases with the increase of the cavity length. (C) 2011 Elsevier B.V. All rights reserved.
文献类型: Article
作者关键词: Ultrafast lasers; Fiber lasers; Mode-locked lasers
KeyWords Plus: SIDE-BAND GENERATION; NORMAL-DISPERSION; RING LASER; DISSIPATIVE SOLITONS; CAVITY DISPERSION; ENERGY
Web of Science 类别: Optics
研究方向: Optics
IDS 号: 902JW 
ISSN: 0030-4018 

第 144 条，共 210 条
标题: Threshold characteristics analysis of one-end-pumped Yb3+-doped gain-guided and index-antiguided fiber laser 
作者: Qu, YB (Qu, Yibin); Zhu, YG (Zhu, Yonggang); Zhou, EY (Zhou, Enyu); Wei, W (Wei, Wei); Peng, B (Peng, Bo)
来源出版物: OPTICS AND LASER TECHNOLOGY  卷: 44  期: 3  页: 646-649  DOI: 10.1016/j.optlastec.2011.09.014  出版年: APR 2012  
Web of Science 核心合集中的 "被引频次": 2 
被引频次合计: 2 
摘要: An exact analytical expression of the threshold pump power for the one-end-pumped Yb3+-doped gain-guided and index-antiguided (CC-IAG) fiber laser has been obtained by solving the improved rate equations (REs) with the additional leakage losses. The effects of Yb3+ concentration, fiber length, core radius and mirror reflectivity on the threshold pump power are discussed. After optimizing, the results show that the laser threshold of GG-IAG fiber laser can be greatly reduced while maintaining single mode oscillation. Compared to the numerical methods, the analytical expression has easy calculation and distinct results. (C) 2011 Elsevier Ltd. All rights reserved.
文献类型: Article
作者关键词: Gain guided; Index anti-guided; Analytical solutions
KeyWords Plus: SINGLE-MODE; CORE
Web of Science 类别: Optics; Physics, Applied
研究方向: Optics; Physics
IDS 号: 859JR 
ISSN: 0030-3992 

第 145 条，共 210 条
标题: A robust random number generator based on differential comparison of chaotic laser signals 
作者: Zhang, JZ (Zhang, Jianzhong); Wang, YC (Wang, Yuncai); Liu, M (Liu, Ming); Xue, LG (Xue, Lugang); Li, P (Li, Pu); Wang, AB (Wang, Anbang); Zhang, MJ (Zhang, Mingjiang)
来源出版物: OPTICS EXPRESS  卷: 20  期: 7  页: 7496-7506  DOI: 10.1364/OE.20.007496  出版年: MAR 26 2012  
Web of Science 核心合集中的 "被引频次": 9 
被引频次合计: 12 
摘要: We experimentally realize a robust real-time random number generator by differentially comparing the signal from a chaotic semiconductor laser and its delayed signal through a 1-bit analog-to-digital converter. The probability density distribution of the output chaotic signal based on the differential comparison method possesses an extremely small coefficient of Pearson's median skewness (1.5 x 10(-6)), which can yield a balanced random sequence much easily than the previously reported method that compares the signal from the chaotic laser with a certain threshold value. Moveover, we experimently demonstrate that our method can stably generate good random numbers at rates of 1.44 Gbit/s with excellent immunity from external perturbations while the previously reported method fails. (C) 2012 Optical Society of America
PubMed ID: 22453429 
文献类型: Article
KeyWords Plus: RANDOM BIT GENERATION; SEMICONDUCTOR-LASERS; OPTICAL FEEDBACK; BANDWIDTH
Web of Science 类别: Optics
研究方向: Optics
IDS 号: 916YJ 
ISSN: 1094-4087 

第 146 条，共 210 条
标题: Numerical investigation of soliton molecules with variable separation in passively mode-locked fiber lasers 
作者: Li, XH (Li, Xiaohui); Wang, YS (Wang, Yishan); Zhao, W (Zhao, Wei); Zhang, W (Zhang, Wei); Hu, XH (Hu, Xiaohong); Gao, CX (Gao, Cunxiao); Zhang, H (Zhang, Han); Yang, Z (Yang, Zhi); Wang, HS (Wang, Hushan); Wang, XL (Wang, Xianglin); Li, C (Li, Cheng); Shen, DY (Shen, Deyuan)
来源出版物: OPTICS COMMUNICATIONS  卷: 285  期: 6  页: 1356-1361  DOI: 10.1016/j.optcom.2011.11.052  出版年: MAR 15 2012  
Web of Science 核心合集中的 "被引频次": 3 
被引频次合计: 3 
摘要: Soliton molecules evolution is numerically investigated in a passively mode-locked fiber laser based on the non-linear polarization rotation (NPR) technique. Peak-to-peak separation of soliton molecules can be controlled by changing either pump strength or cavity linear phase delay appropriately. Moreover, soliton molecules with intensity-independent evolution, separation-independent evolution and large intensity-vibrating evolution are numerically found, respectively. The characteristics of soliton molecules evolution versus linear phase delay or pump strength are given. Periodic stable evolution regimes are found. The separation-controllable soliton molecules can be attributed to the mutual effects of phase delay, Kerr nonlinearity and other parameters of the cavity. Crown Copyright (C) 2011 Published by Elsevier B.V. All rights reserved.
文献类型: Article
作者关键词: Soliton molecules; Fiber laser; Separation controlling
KeyWords Plus: ANOMALOUS-DISPERSION; PAIRS; FIGURE-OF-8; CAVITY
Web of Science 类别: Optics
研究方向: Optics
IDS 号: 903YR 
ISSN: 0030-4018 

第 147 条，共 210 条
标题: Investigation on terahertz vibrational modes of crystalline benzoic acid 
作者: Yan, H (Yan, Hui); Fan, WH (Fan, Wen-Hui); Zheng, ZP (Zheng, Zhuan-Ping)
来源出版物: OPTICS COMMUNICATIONS  卷: 285  期: 6  页: 1593-1598  DOI: 10.1016/j.optcom.2011.11.046  出版年: MAR 15 2012  
Web of Science 核心合集中的 "被引频次": 6 
被引频次合计: 7 
摘要: The characteristic absorption features of crystalline benzoic acid in 0.1-4.0 THz have been measured by terahertz time-domain spectroscopy experimentally. Three sharp and low-intensity peaks are observed in the lowest frequency range of 0.1-1.5 THz. In particular, the absorption peak at 0.63 THz is reported for the first time, to the best of our knowledge. Moreover, theoretical simulations have also been performed, and all measured terahertz absorption features are unambiguously assigned. Our calculations clearly show that the first three absorption features arise from translation motions of dimers held together by hydrogen bonds. (C) 2011 Elsevier B.V. All rights reserved.
文献类型: Article
作者关键词: Benzoic acid; THz-TDS; DFT; MP2; CASTEP
KeyWords Plus: TIME-DOMAIN SPECTROSCOPY; BONDED COMPLEXES; POLYCRYSTALLINE; SACCHARIDES; TEMPERATURE; EXPLOSIVES; MOLECULES; SPECTRA
Web of Science 类别: Optics
研究方向: Optics
IDS 号: 903YR 
ISSN: 0030-4018 

第 148 条，共 210 条
标题: Quantitative monitoring of relative clock wander between signal and sampling sources in asynchronous optical under-sampling system 
作者: Zhang, HX (Zhang, Huixing); Zhao, W (Zhao, Wei)
来源出版物: CHINESE OPTICS LETTERS  卷: 10  期: 3  文献号: 030601  DOI: 10.3788/COL201210.030601  出版年: MAR 10 2012  
Web of Science 核心合集中的 "被引频次": 0 
被引频次合计: 0 
摘要: Optical performance monitoring using asynchronous optical or electrical sampling has gained considerable attention. Relative clock wander between data signal and sampling source is a typical occurrence in such systems. A method for the quantitative monitoring of the relative clock wander in asynchronous optical under-sampling system is presented. With a series of simulations, the clock wanders recovered using this method are in good agreement with the preset clock wanders of different amounts and frequencies for both RZ and NRZ signals. Hence, the reliability and robustness of the method are proven.
文献类型: Article
KeyWords Plus: EYE-DIAGRAM MEASUREMENT; HIGHLY NONLINEAR FIBER; WAVE-GUIDE; SENSITIVITY
Web of Science 类别: Optics
研究方向: Optics
IDS 号: 908TX 
ISSN: 1671-7694 

第 149 条，共 210 条
标题: Analytical and experimental demonstration of depth of field extension for incoherent imaging system with a standard sinusoidal phase mask 
作者: Zhao, H (Zhao, Hui); Li, YC (Li, Yingcai)
来源出版物: CHINESE OPTICS LETTERS  卷: 10  期: 3  文献号: 031101  DOI: 10.3788/COL201210.031101  出版年: MAR 10 2012  
Web of Science 核心合集中的 "被引频次": 1 
被引频次合计: 2 
摘要: The wavefront coding technique is used to enlarge the depth of field (DOF) of incoherent imaging systems. The key to wavefront coding lies in the design of suitable phase masks. To date, numerous kinds of phase masks are proposed. However, further understanding is needed regarding phase mask with its phase function being in a standard sinusoidal form. Therefore, the characteristics of such a phase mask are studied in this letter. Deriving the defocused optical transfer function (OTF) analytically proves that the standard sinusoidal phase mask is effective in extending the DOF, and actual experiments confirm the numerical results. At the same time, with the Fisher information as a criterion, the standard sinusoidal phase mask shows a higher tolerance to focus errors (especially severe focus errors) than the classical cubic phase mask.
文献类型: Article
Web of Science 类别: Optics
研究方向: Optics
IDS 号: 908TX 
ISSN: 1671-7694 

第 150 条，共 210 条
标题: A new time-domain estimation method for period of pulsars 
作者: Li, JX (Li Jian-Xun); Ke, XZ (Ke Xi-Zheng); Zhao, BS (Zhao Bao-Sheng)
来源出版物: ACTA PHYSICA SINICA  卷: 61  期: 6  文献号: 069701  出版年: MAR 2012  
Web of Science 核心合集中的 "被引频次": 2 
被引频次合计: 3 
摘要: The estimation of pulsar period is important for pulsar searching, observation and timing. In this paper, the frequency-domain method which is popular in periodicity searches is analyzed, and further more, a novel method in time-domain is proposed to estimate the cyclo-period of pulsars based on the second-order cyclo-stationary model of the radiation signal. Firstly, the discrete-time observing signal is blocked by assumed period which is alterable. Then, the correlation estimations and their sample variances are computed each as a function of blocking operator index, where the largest peaks display a periodic pattern, from which the cyclo-period can be obtained. Using this method, the period of PSR J0437-4715 with single pulse is estimated well based on original signal, and the period of PSR B1821-24 with double pulses is also estimated based on the simulated signal. The same work is done for the observed data from ATNF EPN pulsar database. The simulation results and the experimental results for many pulsars show that compared with the classical Fourier-transform method, this algorithm is non-sensitive to the noise, and it is effective even though in the case of low signal-to-noise ratio. And it is of low computation complexity compared with the bispectrum coherence method. This method possesses higher popularization value in real-time observation and processing for weak pulsar signal, though it does not work well in dealing with noncontinuous observing data.
文献类型: Article
作者关键词: pulsar searching; period estimation; cyclostationary signal; time-domain estimation
KeyWords Plus: ALGORITHM
Web of Science 类别: Physics, Multidisciplinary
研究方向: Physics
IDS 号: 930VZ 
ISSN: 1000-3290 

第 151 条，共 210 条
标题: Study on static pressure of fiber cable spool based on distributed fiber Bragg grating sensing technology 
作者: Ma, CJ (Ma Cheng-Ju); Ren, LY (Ren Li-Yong); Tang, F (Tang Feng); Qu, ES (Qu En-Shi); Xu, JT (Xu Jin-Tao); Liang, Q (Liang Quan); Wang, J (Wang Jian); Han, X (Han Xu)
来源出版物: ACTA PHYSICA SINICA  卷: 61  期: 5  文献号: 054702  出版年: MAR 2012  
Web of Science 核心合集中的 "被引频次": 0 
被引频次合计: 0 
摘要: Based on the theoretical analysis of the static pressure distribution of fiber cable layer in an optical fiber cable spool, we establish a theoretical model of the force in the cable winding system. Simulations indicate that with the increase of the twining layers, the pressure of every layer in the spool increases very quickly at the beginning and mildly then. The static pressure of fiber cable layers in the spool on cable winding device is sensed by use of distributed fiber Bragg gratings (FBG). The quantitative relationship between the variation of FBG center wavelength and the system pressure is given theoretically. It is shown experimentally that with the increase of the twining layers, the variation pace of FBG center wavelength in every layer is very quick at the beginning and gentle then.. Theoretical simulations coincide with experimental results very well. This technology provides us a real-time method to monitor the pressure of the fiber cable layer in the cable winding process.
文献类型: Article
作者关键词: fiber cable spool; fiber Bragg grating (FBG); axial direction strain; radial direction strain
KeyWords Plus: SENSOR; SENSITIVITY
Web of Science 类别: Physics, Multidisciplinary
研究方向: Physics
IDS 号: 930VT 
ISSN: 1000-3290 

第 152 条，共 210 条
标题: Preliminary research on large-size optical polymer image transmitting fiber faceplate 
作者: Wang, JM (Wang Jin-Meng); Kong, DP (Kong De-Peng); Wang, LL (Wang Li-Li)
来源出版物: ACTA PHYSICA SINICA  卷: 61  期: 5  文献号: 054216  出版年: MAR 2012  
Web of Science 核心合集中的 "被引频次": 2 
被引频次合计: 2 
摘要: Preliminary research on large-size optical polymer image transmitting fiber faceplate is carried out by the stacking-heated fusing method with commercial low-loss optical PMMA fiber which is arranged in a home-made mold by hexagonal packing. A fiber faceplate sample with 2 mm in thickness, 500 mu m in pixel diameter and 59052 in pixel number, is manufactured by cutting and stitching the preforms The fiber faceplate sample has a good image transmission capacity. The resulting large-size optical polymer fiber mosaic faceplate screen has the role that cannot be replaced for large-screen LCD protection and elimination of display seam.
文献类型: Article
作者关键词: large-size; polymer optical fiber faceplate; new manufacturing technology; LCD mosaic screen
Web of Science 类别: Physics, Multidisciplinary
研究方向: Physics
IDS 号: 930VT 
ISSN: 1000-3290 

第 153 条，共 210 条
标题: Study on fabrication and optical properties of Ge-Sb-Se thin films 
作者: Zhang, W (Zhang Wei); Chen, Y (Chen Yu); Fu, J (Fu Jing); Chen, FF (Chen Fei-Fei); Shen, X (Shen Xiang); Dai, SX (Dai Shi-Xun); Lin, CG (Lin Chang-Gui); Xu, TF (Xu Tie-Feng)
来源出版物: ACTA PHYSICA SINICA  卷: 61  期: 5  文献号: 056801  出版年: MAR 2012  
Web of Science 核心合集中的 "被引频次": 0 
被引频次合计: 2 
摘要: Several methods of fabricating chalcogenide thin films are introduced. In this paper, thermal evaporation and radio frequency methods are used to fabricate Ge-Sb-Se thin films. The thicknesses and roughnesses of the films are measured by surface profile-meter. The film growth rates are calculated. The component difference between film and target material is tested by X-ray photoelectron spectroscopy. The third-order optical nonlinearity and the transmission spectra of films fabricated by thermal evaporation are investigated using femto-second Z-scan method and spectrophotometer, to obtain the values of nonlinear refraction, nonlinear absorption and thickness of films. The results show that the films fabricated by thermal evaporation have excellent physical structures and optical properties, and possess promising potential applications in integrated optical devices.
文献类型: Article
作者关键词: chalcogenide glasses; chalcogenide thin films; thermal evaporation; optical properties
KeyWords Plus: CHALCOGENIDE WAVE-GUIDES; GLASSES
Web of Science 类别: Physics, Multidisciplinary
研究方向: Physics
IDS 号: 930VT 
ISSN: 1000-3290 

第 154 条，共 210 条
标题: Steady-state multiple dark photovoltaic spatial solitons 
作者: Zhang, YH (Zhang, Y. H.); Lu, KQ (Lu, K. Q.); Guo, JB (Guo, J. B.); Li, KH (Li, K. H.); Liu, BY (Liu, B. Y.)
来源出版物: EUROPEAN PHYSICAL JOURNAL D  卷: 66  期: 3  文献号: 65  DOI: 10.1140/epjd/e2012-20560-4  出版年: MAR 2012  
Web of Science 核心合集中的 "被引频次": 2 
被引频次合计: 2 
摘要: We theoretically study the formation of the steady state multiple dark photovoltaic spatial solitons in the photovoltaic photorefractive crystal under open-circuit conditions. The results indicate that the initial dark notch width at the entrance face of the crystal is a key parameter for generating an even (or odd) number sequence of multiple dark photovoltaic solitons. The dark notch is generated from a phase or amplitude discontinuity in the center of the input beam. If the initial width of the dark notch is small, only a fundamental soliton or a Y-junction soliton is generated. As the initial width of the dark notch is increased, the dark notch tends to split into an odd (or even) number of multiple dark photovoltaic solitons, realizing a progressive transition from a lower-order soliton to the higher-order multiple solitons. When the multiple dark photovoltaic solitons are generated, the separations between adjacent dark solitons become smaller. Solitons pairs become progressively wider and less visible as their transverse distance from the central dark soliton increases and they move away from each other as they propagate in the photorefractive nonlinear crystal.
文献类型: Article
KeyWords Plus: INDUCED WAVE-GUIDES; PHOTOREFRACTIVE SOLITONS; SEQUENTIAL FORMATION; Y-JUNCTIONS; MEDIA; PROPAGATION; CRYSTALS
Web of Science 类别: Optics; Physics, Atomic, Molecular & Chemical
研究方向: Optics; Physics
IDS 号: 926BE 
ISSN: 1434-6060 

第 155 条，共 210 条
标题: Visual Attention Accelerated Vehicle Detection in Low-Altitude Airborne Video of Urban Environment 
作者: Cao, XB (Cao, Xianbin); Lin, RJ (Lin, Renjun); Yan, PK (Yan, Pingkun); Li, XL (Li, Xuelong)
来源出版物: IEEE TRANSACTIONS ON CIRCUITS AND SYSTEMS FOR VIDEO TECHNOLOGY  卷: 22  期: 3  页: 366-378  DOI: 10.1109/TCSVT.2011.2163443  出版年: MAR 2012  
Web of Science 核心合集中的 "被引频次": 2 
被引频次合计: 2 
摘要: One of the primary goals of the airborne vehicle detection system is to reduce the risks of incident collisions and to relieve traffic jam caused by the increasing number of vehicles. Different from the stationary systems, which are usually fixed on buildings, the airborne systems in unmanned aircrafts or satellites take the advantages of wider view angle and higher mobility. However, detecting vehicles in airborne videos is a challenging task because of the scene complexity and platform movement. The direct application of the traditional image processing techniques to the problem may result in low detection rate or cannot meet the requirements of real-time applications. To address these problems, a new and efficient method composed by two stages, attention focus extraction and vehicle classification is proposed in this paper. Our work makes two key contributions. The first is the introduction of a new attention focus extraction algorithm, which can quickly detect the candidate vehicle regions to make the algorithm focus on much smaller regions for faster computation. The second contribution is a simple and efficient classification process, which is built using the AdaBoost learning algorithm. The classification process, which is a hierarchical structure, is designed to obtain a lower false alarm rate by looking for vehicles in the candidate regions. Experimental results demonstrate that, compared with other representative algorithms, our method can obtain better performance in terms of higher detection rate and lower false positive rate, while meeting the needs of real-time application.
文献类型: Article
作者关键词: Airborne vehicles detection system (AVDS); attention focus; attention shifting; cascade classifier; extent tracing; statistical learning
KeyWords Plus: SURVEILLANCE; INFORMATION
Web of Science 类别: Engineering, Electrical & Electronic
研究方向: Engineering
IDS 号: 904YN 
ISSN: 1051-8215 

第 156 条，共 210 条
标题: Efficient image matching using weighted voting 
作者: Yuan, Y (Yuan, Yuan); Pang, YW (Pang, Yanwei); Wang, KQ (Wang, Kongqiao); Shang, MY (Shang, Mianyou)
来源出版物: PATTERN RECOGNITION LETTERS  卷: 33  期: 4  特刊: SI  页: 471-475  DOI: 10.1016/j.patrec.2011.02.008  出版年: MAR 2012  
Web of Science 核心合集中的 "被引频次": 5 
被引频次合计: 8 
摘要: Spectral decomposition subject to pairwise geometric constraints is one of the most successful image matching (correspondence establishment) methods which is widely used in image retrieval, recognition, registration, and stitching. When the number of candidate correspondences is large, the eigen-decomposition of the affinity matrix is time consuming and therefore is not suitable for real-time computer vision. To overcome the drawback, in this letter we propose to treat each candidate correspondence not only as a candidate but also as a voter. As a voter, it gives voting scores to other candidate correspondences. Based on the voting scores, the optimal correspondences are computed by simple addition and ranking operations. Experimental results on real-data demonstrate that the proposed method is more than one hundred times faster than the classical spectral method while does not decrease the matching accuracy. (C) 2011 Published by Elsevier B.V.
文献类型: Article
作者关键词: Image matching; Spectral technique; Correspondence establishment; Weighted voting
KeyWords Plus: RELEVANCE FEEDBACK; SUBSPACE
Web of Science 类别: Computer Science, Artificial Intelligence
研究方向: Computer Science
IDS 号: 900EC 
ISSN: 0167-8655 

第 157 条，共 210 条
标题: An Optical Fiber Sensor for Remote pH Sensing and Imaging 
作者: Wang, J (Wang, Jian); Wang, LL (Wang, Lili)
来源出版物: APPLIED SPECTROSCOPY  卷: 66  期: 3  页: 300-303  DOI: 10.1366/11-06492  出版年: MAR 2012  
Web of Science 核心合集中的 "被引频次": 2 
被引频次合计: 3 
摘要: A fiber-optical probe for pH sensing and real-time imaging is successfully fabricated by connecting a polymer imaging fiber and a gradient index (GRIN) lens rod which was modified with a sensing film. By employing an improved metallographic microscope, an optical system is designed to cooperate with the probe. This novel technique has high-quality imaging capabilities for observing remote samples while measuring pH. The linear range of the probe is pH 1.2-3.5. This technique overcomes the difficulty that high-quality images cannot be obtained when directly using conventional imaging bundles for pH sensing and imaging. As preliminary applications, the corrosion behavior of an iron screw and the reaction process of rust were investigated in buffer solutions of pH 2.0 and 2.9, respectively. The experiment demonstrated that the pH values of the analytes' surface were higher than that of buffer solutions due to the chemical reaction. It provides great potential for applications in optical multifunctional detection, especially in chemical sensing and biosensing.
PubMed ID: 22449307 
文献类型: Article
作者关键词: Optical fiber sensor; pH sensing; Imaging
KeyWords Plus: FABRICATION; MEMBRANES; CORROSION; ARRAY
Web of Science 类别: Instruments & Instrumentation; Spectroscopy
研究方向: Instruments & Instrumentation; Spectroscopy
IDS 号: 896VK 
ISSN: 0003-7028 

第 158 条，共 210 条
标题: Cross-Coupling of Phenyl Halides with Sodium Dicyanomethanide in the Presence of Tetrakis(triphenyphosphine)palladium 
作者: Wang, J (Wang, Jin); Shu, C (Shu, Cheng); Gao, C (Gao, Chao); Hou, CQ (Hou, Chaoqi); Peng, B (Peng, Bo); Wei, W (Wei, Wei)
来源出版物: ASIAN JOURNAL OF CHEMISTRY  卷: 24  期: 3  页: 1325-1327  出版年: MAR 2012  
Web of Science 核心合集中的 "被引频次": 0 
被引频次合计: 0 
摘要: 1-Aromatic substituted imidizoles were synthesized by a convenient modified process. A cross-coupling reaction of phenyl halides with sodium dicyanomethanide has been achieved to produce the arylmalononitriles coupling products as zwitterionic precursors in high yields by using catalytic tetrakis(triphenyphosphine)palladium under mild conditions. The molecular structure was characterized by H-1 NMR and C-13 NMR spectra, LC-MS and GC-MS. It was found that the products can be easily separated with high yields. When electron-withdrawing groups were employed, substituted phenyl bromide can also be used as the precursors to produce good yield of 87 %. This provides an efficient and practical strategy for the preparation of substituted terminal phenyl malononitriles.
文献类型: Article
作者关键词: Substituted phenyl malononitriles; Zwitterionic precursors; Tetrakis(triphenyphosphine)palladium; Sodium dicyanomethanide
KeyWords Plus: NONLINEAR-OPTICAL CHROMOPHORES; ACTIVE METHYLENE-COMPOUNDS; PUSH-PULL CHROMOPHORES; SYSTEM; COMPLEXES; MALONONITRILE; HYPERPOLARIZABILITY; ARYLMALONONITRILES; FACILE; ROUTE
Web of Science 类别: Chemistry, Multidisciplinary
研究方向: Chemistry
IDS 号: 894YT 
ISSN: 0970-7077 

第 159 条，共 210 条
标题: Analysis and study of the interlaced encoding pixels in Hadamard transform spectral imager based on DMD 
作者: Xu, J (Xu, Jun); Hu, BL (Hu, Bingliang); Feng, DZ (Feng, Dazheng); Fan, XH (Fan, Xiaohui); Qian, QM (Qian, Qingming)
来源出版物: OPTICS AND LASERS IN ENGINEERING  卷: 50  期: 3  页: 458-464  DOI: 10.1016/j.optlaseng.2011.10.007  出版年: MAR 2012  
Web of Science 核心合集中的 "被引频次": 4 
被引频次合计: 6 
摘要: The key innovation in Hadamard transform spectral imager (HTSI) introduced recently is the use of digital micro-mirror device (DMD) to encode spectral information. However, because the size of individual micro-mirrors does not match the detector pixel size or for other unavoidable errors in the optical design and the system assembling, an interlaced encoding phenomenon appears on some pixels of the encoded images obtained from the detector. These interlaced encoding pixels are not encoded based on Hadamard transform, so they should be processed specially in spectrum recovery. This paper analyzes the interlaced encoding phenomenon and proposes a positioning method and a decoding method for the interlaced encoding pixels on the encoded images. In our experiment, we direct a beam of laser into our HTSI and fill the entire field of view: by observing the column vector, which is made up of the gray values of a pixel on the encoded images from the detector in sequence, the interlaced encoding pixels can be distinguished easily and a coefficient is obtained simultaneously, which denotes the ratio of the area between the left part and the right part of the interlaced encoding pixel. By substituting the coefficient and the encoded gray values of the interlaced pixel into its encoding equation, we can recover the spectral elements of the interlaced pixel with ease. By comparing the spectral curve of the interlaced encoding pixels recovered by the method mentioned in this paper and the spectral curves of its two adjacent pixels, we find the decoding results are quite effective. (C) 2011 Elsevier Ltd. All rights reserved.
文献类型: Article
作者关键词: Hadamard transform; DMD; Spectral imager; Interlaced encoding; Decoding method
KeyWords Plus: IMAGING SPECTROMETER
Web of Science 类别: Optics
研究方向: Optics
IDS 号: 892ED 
ISSN: 0143-8166 

第 160 条，共 210 条
标题: Content-adaptive reliable robust lossless data embedding 
作者: An, LL (An, Lingling); Gao, XB (Gao, Xinbo); Yuan, Y (Yuan, Yuan); Tao, DC (Tao, Dacheng); Deng, C (Deng, Cheng); Ji, F (Ji, Feng)
来源出版物: NEUROCOMPUTING  卷: 79  页: 1-11  DOI: 10.1016/j.neucom.2011.08.019  出版年: MAR 1 2012  
Web of Science 核心合集中的 "被引频次": 8 
被引频次合计: 8 
摘要: It is well known that robust lossless data embedding (RLDE) methods can be used to protect copyright of digital images when the intactness of host images is highly demanded and the unintentional attacks may be encountered in data communication. However, the existing RLDE methods cannot be applied satisfactorily to the practical scenarios due to different drawbacks, e.g., serious "salt-and-pepper" noise, low capacity and unreliable reversibility. In this paper, we propose an effective solution to RLDE by improving the histogram rotation (HR)-based embedding model. The proposed method is a content-adaptive reliable RLDE or CAR for short. It eliminates the "salt-and-pepper" noise in HR by the pixel adjustment mechanism. Therefore, reliable regions for embedding can be well constructed. Furthermore, we basically expect the watermark strengths to be adaptive to different image contents, and thus we have a chance to make an effective tradeoff between invisibility and robustness. The luminance masking together with the threshold strategy is duly adopted in the proposed RLDE method, so the just noticeable distortion thresholds of different local regions can be well utilized to control the watermark strengths. Experimental evidence on 300 test images including natural, medical and synthetic aperture radar (SAR) images demonstrates the effectiveness of the proposed data embedding method. (C) 2011 Elsevier B.V. All rights reserved.
文献类型: Article
作者关键词: Histogram rotation; Just noticeable distortion; Robust lossless data embedding
KeyWords Plus: STATISTICAL QUANTITY HISTOGRAM; DIGITAL WATERMARKING; IMAGE WATERMARKING
Web of Science 类别: Computer Science, Artificial Intelligence
研究方向: Computer Science
IDS 号: 890IS 
ISSN: 0925-2312 

第 161 条，共 210 条
标题: Solitons in thermal media with periodic modulation of linear refractive index 
作者: Ma, XK (Ma, Xuekai); Yang, ZJ (Yang, Zhenjun); Lu, DQ (Lu, Daquan); Hu, W (Hu, Wei)
来源出版物: OPTICS COMMUNICATIONS  卷: 285  期: 5  页: 774-778  DOI: 10.1016/j.optcom.2011.11.002  出版年: MAR 1 2012  
Web of Science 核心合集中的 "被引频次": 0 
被引频次合计: 0 
摘要: We address the existence and properties of solitons in thermal media with periodic modulation of linear refractive index. Many kinds of solitons in such optical lattices, including symmetric and antisymmetric lattices, are found under different conditions. We study the influence of the refractive index difference between two different layers on solitons. It is also found that there do not exist cutoff value of propagation constant and soliton power for shifted lattice solitons. In addition, the solitons launched away from their stationary position may propagate without oscillation when the confinement from lattices is strong. (C) 2011 Elsevier B.V. All rights reserved.
文献类型: Article
作者关键词: Nonlocal soliton; Thermal media; Optical lattice; Shifted soliton; Beam propagation; Stationary position
KeyWords Plus: NONLOCAL NONLINEAR MEDIA; SURFACE SOLITONS; OPTICAL SOLITONS; COMPRESSION; PROPAGATION
Web of Science 类别: Optics
研究方向: Optics
IDS 号: 891EO 
ISSN: 0030-4018 

第 162 条，共 210 条
标题: Parallelized Evolutionary Learning for Detection of Biclusters in Gene Expression Data 
作者: Huang, QH (Huang, Qinghua); Tao, DC (Tao, Dacheng); Li, XL (Li, Xuelong); Liew, AWC (Liew, Alan Wee-Chung)
来源出版物: IEEE-ACM TRANSACTIONS ON COMPUTATIONAL BIOLOGY AND BIOINFORMATICS  卷: 9  期: 2  页: 560-570  DOI: 10.1109/TCBB.2011.53  出版年: MAR-APR 2012  
Web of Science 核心合集中的 "被引频次": 4 
被引频次合计: 4 
摘要: The analysis of gene expression data obtained from microarray experiments is important for discovering the biological process of genes. Biclustering algorithms have been proven to be able to group the genes with similar expression patterns under a number of experimental conditions. In this paper, we propose a new biclustering algorithm based on evolutionary learning. By converting the biclustering problem into a common clustering problem, the algorithm can be applied in a search space constructed by the conditions. To further reduce the size of the search space, we randomly separate the full conditions into a number of condition subsets (subspaces), each of which has a smaller number of conditions. The algorithm is applied to each subspace and is able to discover bicluster seeds within a limited computing time. Finally, an expanding and merging procedure is employed to combine the bicluster seeds into larger biclusters according to a homogeneity criterion. We test the performance of the proposed algorithm using synthetic and real microarray data sets. Compared with several previously developed biclustering algorithms, our algorithm demonstrates a significant improvement in discovering additive biclusters.
PubMed ID: 21383419 
文献类型: Article
作者关键词: Biclustering; genetic learning; subdimensional search strategy; gene expression data analysis
KeyWords Plus: MICROARRAY DATA-ANALYSIS; CLUSTERING ANALYSIS; SET
Web of Science 类别: Biochemical Research Methods; Computer Science, Interdisciplinary Applications; Mathematics, Interdisciplinary Applications; Statistics & Probability
研究方向: Biochemistry & Molecular Biology; Computer Science; Mathematics
IDS 号: 882JS 
ISSN: 1545-5963 

第 163 条，共 210 条
标题: Investigation of the arbitrary waveform semiconductor laser as seed light source for high energy laser 
作者: Wang, HY (Wang, Hongyun); Da, ZS (Da, Zhengshang); Liu, BY (Liu, Baiyu); Liu, H (Liu, Hui)
来源出版物: MICROWAVE AND OPTICAL TECHNOLOGY LETTERS  卷: 54  期: 3  页: 751-755  DOI: 10.1002/mop.26652  出版年: MAR 2012  
Web of Science 核心合集中的 "被引频次": 0 
被引频次合计: 0 
摘要: A pulse semiconductor laser modulated by arbitrary shaping electrical waveform is produced and the generated optical pulse can be taken as the seed resource for high-power laser facilities.Based on ultrawide band microwave device and microstrip line transmission delay application, an all-solid-state circuit for generating arbitrary modulation pulse to modulate the semiconductor laser is fabricated. For improving the semiconductor laser power, the output laser pulse is sent into erbium-doped fiber master oscillator power amplifier architecture for amplification. In the experiment, the output laser pulse can be arbitrarily adjusted at 1547.9 nm center wavelength, less than 10 ns duration, lower than 100 kHz repetition rate, and 330 ps time domain adjustment. (C) 2012 Wiley Periodicals, Inc. Microwave Opt Technol Lett 54:751-755, 2012; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.26652
文献类型: Article
作者关键词: semiconductor laser; pulse shaping; modulation; arbitrary waveform generator
KeyWords Plus: PULSE; GENERATION; BAND
Web of Science 类别: Engineering, Electrical & Electronic; Optics
研究方向: Engineering; Optics
IDS 号: 879MG 
ISSN: 0895-2477 

第 164 条，共 210 条
标题: Terahertz absorption spectra of benzene-1,2-diol, benzene-1,3-diol and benzene-1,4-diol 
作者: Zheng, ZP (Zheng, Zhuan-Ping); Fan, WH (Fan, Wen-Hui); Yan, H (Yan, Hui)
来源出版物: CHEMICAL PHYSICS LETTERS  卷: 525-26  页: 140-143  DOI: 10.1016/j.cplett.2011.12.062  出版年: FEB 16 2012  
Web of Science 核心合集中的 "被引频次": 7 
被引频次合计: 8 
摘要: The terahertz spectra (8-128 cm(-1)) of three structural isomers have been measured using terahertz time-domain spectroscopy at room temperature. Substantial differences among these THz spectra have been found and implied that THz-TDS is an excellent tool to identify isomers. Numerical calculation based on solid-state density functional theory has been carried out and assigned the observed THz features theoretically. Good agreement between the calculated and experimentally measured spectra for benzene-1,2-diol and benzene-1,3-diol has been achieved. According to the calculated results, it is found that the measured THz spectra of these two isomers mainly originate from intermolecular vibrations. (C) 2011 Elsevier B.V. All rights reserved.
文献类型: Article
KeyWords Plus: DENSITY-FUNCTIONAL THEORY; TIME-DOMAIN SPECTROSCOPY; VIBRATIONAL-SPECTRA; POLYMORPHS; CASTEP
Web of Science 类别: Chemistry, Physical; Physics, Atomic, Molecular & Chemical
研究方向: Chemistry; Physics
IDS 号: 891OG 
ISSN: 0009-2614 

第 165 条，共 210 条
标题: Effect of dehydration techniques on the fluorescence spectral features and OH absorption of heavy metals containing fluoride tellurite glasses 
作者: Wang, PF (Wang, P. F.); Li, WN (Li, W. N.); Peng, B (Peng, B.); Lu, M (Lu, M.)
来源出版物: JOURNAL OF NON-CRYSTALLINE SOLIDS  卷: 358  期: 4  页: 788-793  DOI: 10.1016/j.jnoncrysol.2011.12.029  出版年: FEB 15 2012  
Web of Science 核心合集中的 "被引频次": 2 
被引频次合计: 2 
摘要: Heavy metal containing fluoride tellurite glasses were prepared by different dehydration techniques and the effects of dehydration techniques on fluorescence spectral features, OH content and volatilization of the glass compositions were systematically studied by means of fluorescence spectral measurements FTIR and energy-dispersive X-ray spectrometer. Experimental results indicated that different dehydration induced difference in actual compositions of the glasses that resulted in the variation of their fluorescence spectral features, and melting the glass frits in close environment with mechanical stirring and simultaneous bubbling dry O-2 + CCl4 mixture in a O-2-rich environment was much more effective to remove the OH groups in the glass matrix, through which an OH absorption coefficient and absorption concentration could be efficiently reduced to as low as 1.09 cm(-1) and 1.17 x 10(19) cm(-3), respectively. The low OH content contributed to the increase in fluorescence lifetime, and resulted in the improvement of gain characteristic. The bubbling time of dry O-2 + CCl4 Mixture was optimized via OH absorption concentration investigation. (c) 2011 Elsevier B.V. All rights reserved.
文献类型: Article
作者关键词: Dehydration; Tellurite glasses; FTIR spectra; OH absorption; Gain parameters
KeyWords Plus: UP-CONVERSION; FIBER
Web of Science 类别: Materials Science, Ceramics; Materials Science, Multidisciplinary
研究方向: Materials Science
IDS 号: 900CZ 
ISSN: 0022-3093 

第 166 条，共 210 条
标题: Widely tunable femtosecond optical parametric oscillator based on silicon-on-insulator waveguides 
作者: Wen, J (Wen, Jin); Liu, HJ (Liu, Hongjun); Huang, N (Huang, Nan); Sun, QB (Sun, Qibing); Zhao, W (Zhao, Wei)
来源出版物: OPTICS EXPRESS  卷: 20  期: 4  页: 3490-3498  DOI: 10.1364/OE.20.003490  出版年: FEB 13 2012  
Web of Science 核心合集中的 "被引频次": 4 
被引频次合计: 4 
摘要: A femtosecond optical parametric oscillator (OPO) based on silicon-on-insulator (SOI) waveguide is proposed and analyzed numerically. By utilizing split-step Fourier method (SSFM), it is demonstrated that ultra-wide tunable wavelength femtosecond pulse can be realized under the phase matching condition. Due to the interaction between nonlinearity and flexible dispersion design, the output signal wavelength can be tuned from 1645 to 1805 nm and the idler wavelength can be tuned from 1350 to 1456 nm. Moreover, the peak power of the output signal pulse exceeds 10 W from 1700 to 1770 nm with the pump peak power 50 W. The proposed OPO exhibits compact configuration and can find important applications in integrated broadband optical source. (C) 2012 Optical Society of America
PubMed ID: 22418108 
文献类型: Article
KeyWords Plus: SELF-PHASE-MODULATION; WAVELENGTH CONVERSION; FREQUENCY-CONVERSION; 2-PHOTON ABSORPTION; PHOTONIC WIRES; GENERATION; PULSES; NANOWAVEGUIDES; AMPLIFICATION; PROPAGATION
Web of Science 类别: Optics
研究方向: Optics
IDS 号: 902MH 
ISSN: 1094-4087 

第 167 条，共 210 条
标题: Global estimates of lunar iron and titanium contents from the Chang' E-1 IIM data 
作者: Wu, YZ (Wu, Yunzhao); Xue, B (Xue, Bin); Zhao, BC (Zhao, Baochang); Lucey, P (Lucey, Paul); Chen, J (Chen, Jun); Xu, XS (Xu, Xisheng); Li, CL (Li, Chunlai); Ouyang, ZY (Ouyang, Ziyuan)
来源出版物: JOURNAL OF GEOPHYSICAL RESEARCH-PLANETS  卷: 117  文献号: E02001  DOI: 10.1029/2011JE003879  出版年: FEB 3 2012  
Web of Science 核心合集中的 "被引频次": 7 
被引频次合计: 10 
摘要: Until recently, global high spatial resolution maps of FeO and TiO2 of the Moon were only derived from Clementine data. In this study, we show global maps of FeO and TiO2 using Chang'E-1 Interference Imaging Spectrometer (IIM) at a spatial resolution of 200 m/pixel. With a newly developed calibration presented here, spectra obtained by IIM compare well with telescopic spectra. Spectral parameters previously shown to be sensitive to iron and titanium, derived from the calibrated IIM data are highly correlated with the measured elemental concentration with R-2 = 0.96 for FeO and 0.95 for TiO2. The maps were developed using this calibration. Histograms of basalt FeO estimates have a negatively skewed distribution, while TiO2 distributions are unimodal. They also revealed that the lunar highland crust is relatively uniform on the quadrant scale (several hundred to thousand kilometers scale) but inhomogenous on the global scale. The area of highest elevation of the Moon has very low FeO and TiO2 raising the question about South Pole-Aitken (SPA) (whether its ejecta deposits covered the highest elevation and when it was formed). Although the average FeO and TiO2 abundances for basalts are highly correlated, local areas of elevated iron can be associated with both high and low titanium.
文献类型: Article
KeyWords Plus: CLEMENTINE; SURFACE; TIO2; MOON; FEO; INTERFEROMETER; PROSPECTOR; ARRAY; SPECTROMETER; MINERALOGY
Web of Science 类别: Geochemistry & Geophysics
研究方向: Geochemistry & Geophysics
IDS 号: 887UO 
ISSN: 0148-0227 

第 168 条，共 210 条
标题: The Characterization of Sputtered Zr-Ge-N Thin Films as Diffusion Barriers Between Copper and Silicon 
作者: Yang, JJ (Yang, J. J.); Liu, B (Liu, B.); Liao, XD (Liao, X. D.); Jiao, GH (Jiao, G. H.); Xu, KW (Xu, K. W.)
来源出版物: RARE METAL MATERIALS AND ENGINEERING  卷: 41  页: 120-123  增刊: 1  出版年: FEB 2012  
Web of Science 核心合集中的 "被引频次": 0 
被引频次合计: 0 
摘要: The main purpose of the present micro-structural analysis by transmission electron microscopy (TEM) and X-ray diffraction (XRD) was to investigate whether amorphous Zr-Ge-N films are a potential candidate as a diffusion barrier for Cu wiring used in Si devices. The Zr-Ge-N films were prepared by a radio frequency (RF) reactive magnetron sputter-deposition technique using N-2 and Ar mixed gas, and the film structure was found to be sensitive to the gas flow ratio of N-2 vs. Ar during sputtering. Polycrystalline Zr-Ge-N films were obtained when the N-2/(Ar+N-2) ratio was smaller than 0.2 and amorphous-like Zr-Ge-N films were obtained when the ratio was larger than 0.3. Diffusion barrier test was performed by annealing the Cu/Zr-Ge-N/Si film stack under Ar atmosphere. The deposited Zr-Ge-N(C) films remained amorphous even after high temperature annealing. The Cu diffusion profile in the film was assessed by the Auger electron spectroscopy (AES). The results indicate that Cu diffusion was minimal in amorphous Zr-Ge-N(C) films even at high annealing temperatures of 800 degrees C.
文献类型: Article
作者关键词: Zr-Ge-N films; diffusion barrier; micro-structural; thermal stability
KeyWords Plus: SI; METALLIZATION; INTERCONNECTS; BEHAVIOR
Web of Science 类别: Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering
研究方向: Materials Science; Metallurgy & Metallurgical Engineering
IDS 号: 937CF 
ISSN: 1002-185X 

第 169 条，共 210 条
标题: Formation of multiple dark photovoltaic spatial solitons 
作者: Zhang, YH (Zhang, Yuhong); Lu, KQ (Lu, Keqing); Guo, JB (Guo, Jianbang); Long, XW (Long, Xuewen); Hu, XH (Hu, Xiaohong); Li, KH (Li, Kehao)
来源出版物: PRAMANA-JOURNAL OF PHYSICS  卷: 78  期: 2  页: 265-275  DOI: 10.1007/s12043-011-0226-9  出版年: FEB 2012  
Web of Science 核心合集中的 "被引频次": 1 
被引频次合计: 1 
摘要: We theoretically study the formation of multiple dark photovoltaic soliton splitting in the quasi-steady-state and steady-state regimes under open-circuit conditions. We find that the initial width of the dark notch at the entrance face of the crystal is a key parameter for generating an even (or odd) number sequence of dark coherent photovoltaic solitons. If the initial width of the dark notch is small, only a fundamental soliton or Y-junction soliton pair is generated. As the initial width of the dark notch is increased, the dark notch tends to split into an odd (or even) number of multiple dark photovoltaic solitons, which realizes a progressive transition from a low-order soliton to a sequence of higher-order solitons. The soliton pairs far away from the centre have bigger width and less visibility. In addition, when the distance from the centre of the dark notch increases, the separations between adjacent dark stripes become slightly smaller.
文献类型: Article
作者关键词: Photorefractive effect; photovoltaic soliton splitting; multiple dark solitons; beam propagation method
KeyWords Plus: PHOTOREFRACTIVE SCREENING SOLITONS; QUASI-STEADY-STATE; WAVE-GUIDES; TEMPORAL BEHAVIOR; Y-JUNCTIONS; BRIGHT; MEDIA; PROPAGATION; CRYSTALS
Web of Science 类别: Physics, Multidisciplinary
研究方向: Physics
IDS 号: 929IQ 
ISSN: 0304-4289 

第 170 条，共 210 条
标题: Nonrigid Structure-From-Motion From 2-D Images Using Markov Chain Monte Carlo 
作者: Zhou, HY (Zhou, Huiyu); Li, XL (Li, Xuelong); Sadka, AH (Sadka, Abdul H.)
来源出版物: IEEE TRANSACTIONS ON MULTIMEDIA  卷: 14  期: 1  页: 168-177  DOI: 10.1109/TMM.2011.2170406  出版年: FEB 2012  
Web of Science 核心合集中的 "被引频次": 2 
被引频次合计: 2 
摘要: In this paper we present a new method for simultaneously determining 3-D shape and motion of a nonrigid object from uncalibrated 2-D images without assuming the distribution characteristics. A nonrigid motion can be treated as a combination of a rigid rotation and a nonrigid deformation. To seek accurate recovery of deformable structures, we estimate the probability distribution function of the corresponding features through random sampling, incorporating an established probabilistic model. The fitting between the observation and the projection of the estimated 3-D structure will be evaluated using a Markov chain Monte Carlo based expectation maximization algorithm. Applications of the proposed method to both synthetic and real image sequences are demonstrated with promising results.
文献类型: Article
作者关键词: Markov chain Monte Carlo; nonrigid; structure from motion; uncalibrated
KeyWords Plus: SHAPE; ALGORITHM; TRACKING; RECOVERY; LIKELIHOOD; STREAMS; MODELS; MCMC; EM
Web of Science 类别: Computer Science, Information Systems; Computer Science, Software Engineering; Telecommunications
研究方向: Computer Science; Telecommunications
IDS 号: 924OL 
ISSN: 1520-9210 

第 171 条，共 210 条
标题: Generation of broadband cascaded four-wave mixing products in silicon-on-insulator waveguide 
作者: Wen, J (Wen, Jin); Liu, HJ (Liu, Hongjun); Huang, N (Huang, Nan); Sun, QB (Sun, Qibing); Zhao, W (Zhao, Wei)
来源出版物: OPTICAL ENGINEERING  卷: 51  期: 2  文献号: 024601  DOI: 10.1117/1.OE.51.2.024601  出版年: FEB 2012  
Web of Science 核心合集中的 "被引频次": 0 
被引频次合计: 0 
摘要: We present a new method to generate broadband cascaded four-wave mixing (FWM) products in the silicon-on-insulator (SOI) waveguide. A simulation model of the nonlinear Schrodinger equation is used to describe the cascaded FWM in the SOI waveguide, which consists of launching two strong pump waves near the zero-dispersion wavelength of the very short (just a few millimeters) SOI waveguide. The numerical results based on the split step Fourier method have demonstrated that the output cascaded FWM products represent bandwidth of more than 1000 nm (range from C-band to IR-band). We also analyze the remarkable influences of parameters of the waveguide length, the pump power, and the dispersion slope on the cascaded FWM products in the SOI waveguide. (c) 2012 Society of Photo-Optical Instrumentation Engineers (SPIE). [DOI: 10.1117/1.OE.51.2.024601]
文献类型: Article
作者关键词: nonlinear optics; integrated optics; four-wave mixing; silicon; waveguides
KeyWords Plus: OPTICAL-FIBERS; RAMAN LASER; DISPERSION; FREQUENCY; MODULATOR; REGION
Web of Science 类别: Optics
研究方向: Optics
IDS 号: 925RS 
ISSN: 0091-3286 

第 172 条，共 210 条
标题: Initialization Independent Clustering With Actively Self-Training Method 
作者: Nie, FP (Nie, Feiping); Xu, D (Xu, Dong); Li, XL (Li, Xuelong)
来源出版物: IEEE TRANSACTIONS ON SYSTEMS MAN AND CYBERNETICS PART B-CYBERNETICS  卷: 42  期: 1  页: 17-27  DOI: 10.1109/TSMCB.2011.2161607  出版年: FEB 2012  
Web of Science 核心合集中的 "被引频次": 3 
被引频次合计: 3 
摘要: The results of traditional clustering methods are usually unreliable as there is not any guidance from the data labels, while the class labels can be predicted more reliable by the semisupervised learning if the labels of partial data are given. In this paper, we propose an actively self-training clustering method, in which the samples are actively selected as training set to minimize an estimated Bayes error, and then explore semisupervised learning to perform clustering. Traditional graph-based semisupervised learning methods are not convenient to estimate the Bayes error; we develop a specific regularization framework on graph to perform semisupervised learning, in which the Bayes error can be effectively estimated. In addition, the proposed clustering algorithm can be readily applied in a semisupervised setting with partial class labels. Experimental results on toy data and real-world data sets demonstrate the effectiveness of the proposed clustering method on the unsupervised and the semisupervised setting. It is worthy noting that the proposed clustering method is free of initialization, while traditional clustering methods are usually dependent on initialization.
PubMed ID: 22086542 
文献类型: Article
作者关键词: Active learning; initialization independent clustering; self-training; spectral clustering (SC)
Web of Science 类别: Automation & Control Systems; Computer Science, Artificial Intelligence; Computer Science, Cybernetics
研究方向: Automation & Control Systems; Computer Science
IDS 号: 916IZ 
ISSN: 1083-4419 

第 173 条，共 210 条
标题: TiO2 modified 547 holes microstructured polymer optical fiber preform and basic application on photocatalytic 
作者: Li, DD (Li Dong-Dong); Wang, LL (Wang Li-Li)
来源出版物: ACTA PHYSICA SINICA  卷: 61  期: 3  文献号: 034212  出版年: FEB 2012  
Web of Science 核心合集中的 "被引频次": 1 
被引频次合计: 1 
摘要: In this paper, we report on a novel photocatalytic reactor having 547 pieces of TiO2-nanofilm-modified capillaries, which is derived from a microstructured polymer optical fiber (MPOF) preform. TiO2-film-modified MPOF preform is obtained by directly inhaling P25-doped TiO2 sol into array holes of MPOF and forming TiO2 film on their side walls. The MPOF perform acts as not only a light-transmitting media (rolling-up thin film waveguide, collecting and transmitting light into the TiO2 thin film), but also a TiO(2)supporting and waste-water pipe to supply for photocatalytic degradation of toxic organic solute. Methylene blue (MB) is chosen as a model contaminant in water. The effects of loading quantity of TiO2, pH of MB and initial concentration of MB on photocatalytic degradation are investigated. The photocatalytic reactor has so large surface area for TiO2 loading that photodegradation efficiency is enhanced. As far as we know, the photocatalytic reactor with functions of collecting and transmitting light, conveying matter and loading catalyst has not been reported before.
文献类型: Article
作者关键词: microstructured polymer optical fiber preform; photocatalytic degradation; TiO2 nanoparticle; methylene blue
KeyWords Plus: SENSITIZED SOLAR-CELLS; MONOLITH REACTOR; DEGRADATION; DYES; DECOLORIZATION
Web of Science 类别: Physics, Multidisciplinary
研究方向: Physics
IDS 号: 901ZR 
ISSN: 1000-3290 

第 174 条，共 210 条
标题: Enhanced open-circuit voltage of two side chain conjugated polythiophene derivatives blended with indene-C-60 bisadduct 
作者: Gao, C (Gao, Chao); Qu, B (Qu, Bo); Chen, D (Chen, Dong); Cong, ZY (Cong, Zhiyuan); Liu, JQ (Liu, Jianqun); Chen, J (Chen, Jian); An, ZW (An, Zhongwei); Chen, ZJ (Chen, Zhijian); Xiao, LX (Xiao, Lixin); Wei, W (Wei, Wei); Gong, QH (Gong, Qihuang)
来源出版物: REACTIVE & FUNCTIONAL POLYMERS  卷: 72  期: 2  页: 122-126  DOI: 10.1016/j.reactfunctpolym.2011.11.004  出版年: FEB 2012  
Web of Science 核心合集中的 "被引频次": 5 
被引频次合计: 5 
摘要: Two side chain conjugated polythiophene copolymer: poly[3-(5'-octylthienylenevinyl) thiophene]-thiophene (P1) and poly(3-[4-(2-ethyl-hexyloxy)-phenylvinyl]-thiophene)-thiophene (P2) were synthesized. Polymer photovoltaic solar cells using P1 and P2 as donor and a high LUMO energy level fullerene derivative indene-C-60 bisadduct (IC(60)BA) as acceptor were demonstrated. The polymer solar cells (PSCs) based P1/IC(60)BA and P2/IC(60)BA showed enhanced open circuit voltage (V-oc) of 0.89 and 0.88 V respectively, in comparison with that of P1/PC61BM and P2/PC61BM as 0.58 and 0.56 V. respectively. The improved V-oc of IC(60)BA as acceptor in PSCs is benefited from the higher LUMO energy levels of the C-60 derivatives. The power conversion efficiency of the PSCs based on P1/IC(60)BA and P2/IC(60)BA were 0.32% and 0.35%, respectively. (C) 2011 Elsevier Ltd. All rights reserved.
文献类型: Article
作者关键词: Photovoltaic cells; Bulk-heterojunction; Side chain conjugated polymer; Indene-C-60 bisadduct
KeyWords Plus: POLYMER SOLAR-CELLS; ABSORPTION-SPECTRA; EFFICIENCIES; ACCEPTOR; NETWORK; DONOR; BAND
Web of Science 类别: Chemistry, Applied; Engineering, Chemical; Polymer Science
研究方向: Chemistry; Engineering; Polymer Science
IDS 号: 902CF 
ISSN: 1381-5148 
电子 ISSN: 1873-166X 

第 175 条，共 210 条
标题: Joint Learning for Single-Image Super-Resolution via a Coupled Constraint 
作者: Gao, XB (Gao, Xinbo); Zhang, KB (Zhang, Kaibing); Tao, DC (Tao, Dacheng); Li, XL (Li, Xuelong)
来源出版物: IEEE TRANSACTIONS ON IMAGE PROCESSING  卷: 21  期: 2  页: 469-480  DOI: 10.1109/TIP.2011.2161482  出版年: FEB 2012  
Web of Science 核心合集中的 "被引频次": 29 
被引频次合计: 33 
摘要: The neighbor-embedding (NE) algorithm for single-image super-resolution (SR) reconstruction assumes that the feature spaces of low-resolution (LR) and high-resolution (HR) patches are locally isometric. However, this is not true for SR because of one-to-many mappings between LR and HR patches. To overcome or at least to reduce the problem for NE-based SR reconstruction, we apply a joint learning technique to train two projection matrices simultaneously and to map the original LR and HR feature spaces onto a unified feature subspace. Subsequently, the k-nearest neighbor selection of the input LR image patches is conducted in the unified feature subspace to estimate the reconstruction weights. To handle a large number of samples, joint learning locally exploits a coupled constraint by linking the LR-HR counterparts together with the K-nearest grouping patch pairs. In order to refine further the initial SR estimate, we impose a global reconstruction constraint on the SR outcome based on the maximum a posteriori framework. Preliminary experiments suggest that the proposed algorithm outperforms NE-related baselines.
PubMed ID: 22262669 
文献类型: Article
作者关键词: Grouping patch pairs (GPPs); joint learning; neighbor embedding (NE); super-resolution (SR)
KeyWords Plus: HIGH-RESOLUTION IMAGE; QUALITY ASSESSMENT; MOTION ESTIMATION; SUPER RESOLUTION; INTERPOLATION; RECONSTRUCTION; RESTORATION; RECOGNITION; ALGORITHM; SEQUENCE
Web of Science 类别: Computer Science, Artificial Intelligence; Engineering, Electrical & Electronic
研究方向: Computer Science; Engineering
IDS 号: 896IU 
ISSN: 1057-7149 

第 176 条，共 210 条
标题: Wavelength-Switchable and Wavelength-Tunable All-Normal-Dispersion Mode-Locked Yb-Doped Fiber Laser Based on Single-Walled Carbon Nanotube Wall Paper Absorber 
作者: Li, XH (Li, Xiao-Hui); Wang, YG (Wang, Yong-Gang); Wang, YS (Wang, Yi-Shan); Hu, XH (Hu, Xiao-Hong); Zhao, W (Zhao, Wei); Liu, XL (Liu, Xiang-Lian); Yu, J (Yu, Jia); Gao, CX (Gao, Cun-Xiao); Zhang, W (Zhang, Wei); Yang, Z (Yang, Zhi); Li, C (Li, Cheng); Shen, DY (Shen, De-Yuan)
来源出版物: IEEE PHOTONICS JOURNAL  卷: 4  期: 1  页: 234-241  DOI: 10.1109/JPHOT.2012.2183862  出版年: FEB 2012  
Web of Science 核心合集中的 "被引频次": 13 
被引频次合计: 13 
摘要: We demonstrate a compact wavelength-tunable and -switchable mode-locked Yb-doped fiber (YDF) laser based on single-walled carbon nanotube (SWCNT) wall paper absorber. Two mechanisms coexist in the fiber cavity. The switchable mode-locked state can be obtained between two wavelengths depending on the fiber-loop-induced cavity birefringence. Because of the intensity-dependent transmission distribution, the proposed fiber laser can be operated in the tunable wavelength mode-locked state from 1025 to 1037 nm. The spectral bandwidth varied from 1.1 to 2.4 nm depending on the operating wavelength and the pump power with pulse duration of hundreds of picoseconds. The average wavelength spacing is 3.6 nm, which can be changed, corresponding to the birefringence of the fiber cavity. Moreover, stable wavelength-tunable mode locking is obtained at room temperature.
文献类型: Article
作者关键词: Fiber lasers; mode-locked lasers; tunable lasers; carbon nanotubes and confined systems
KeyWords Plus: DUAL-WAVELENGTH; RING LASER; COMB FILTER; SOLITON
Web of Science 类别: Engineering, Electrical & Electronic; Optics; Physics, Applied
研究方向: Engineering; Optics; Physics
IDS 号: 891CQ 
ISSN: 1943-0655 

第 177 条，共 210 条
标题: All-fiber polarization interference filters based on 45 degrees-tilted fiber gratings 
作者: Yan, ZJ (Yan, Zhijun); Mou, CB (Mou, Chengbo); Wang, HS (Wang, Hushan); Zhou, KM (Zhou, Kaiming); Wang, YS (Wang, Yishan); Zhao, W (Zhao, Wei); Zhang, L (Zhang, Lin)
来源出版物: OPTICS LETTERS  卷: 37  期: 3  页: 353-355  出版年: FEB 1 2012  
Web of Science 核心合集中的 "被引频次": 9 
被引频次合计: 9 
摘要: We report all-fiber polarization interference filters, known as Lyot and Lyot-Ohman filters, based on alternative concatenation of UV-inscribed fiber gratings with structure tilted at 45 degrees and polarization maintaining (PM) fiber cavities. Such filters generate comb-like transmission of linear polarization output. The free spectral range (FSR) of a single-stage (Lyot) filter is PM fiber cavity length dependent, as a 20 cm long cavity showed a 26.6 nm FSR while the 40 cm one exhibited a 14.8 nm FSR. Furthermore, we have theoretically and experimentally demonstrated all-fiber 2-stage and 3-stage Lyot-Ohman filters, giving more freedom in tailoring the transmission characteristics. (C) 2012 Optical Society of America
PubMed ID: 22297350 
文献类型: Article
KeyWords Plus: LYOT FILTER; BRAGG GRATINGS; LASER
Web of Science 类别: Optics
研究方向: Optics
IDS 号: 894DQ 
ISSN: 0146-9592 

第 178 条，共 210 条
标题: Femtosecond laser-induced surface structures to significantly improve the thermal emission of light from metals 
作者: Yang, J (Yang, J.); Yang, Y (Yang, Y.); Zhao, B (Zhao, B.); Wang, Y (Wang, Y.); Zhu, X (Zhu, X.)
来源出版物: APPLIED PHYSICS B-LASERS AND OPTICS  卷: 106  期: 2  页: 349-355  DOI: 10.1007/s00340-011-4834-3  出版年: FEB 2012  
Web of Science 核心合集中的 "被引频次": 2 
被引频次合计: 2 
摘要: Extraordinary thermal emission properties of the metallic surface microstructures induced by femtosecond lasers are investigated in both experiment and theory. Within the spectral range of 4-17 mu m, the measured maximum thermal emissivities at different temperatures enhance significantly to about 100%. Especially for the coral-like surface structure, the improved thermal emission behaviors can extend largely over the whole spectrum rather than happening at some distinctive wavelengths. Moreover, the enhancement factor of the thermal emissivity is observed to depend on the wavelength and the idiographic morphology of the microstructures. This phenomenon can be understood well by equivalent recognizing the SPP field coupling assisted transmission of blackbody radiation through the microstructured interfaces, and the finite-difference time-domain simulations elucidate the underlying physical pictures.
文献类型: Article
KeyWords Plus: PHOTONIC CRYSTALS; TRANSMISSION; PULSES; GENERATION; SILICON; ARRAYS
Web of Science 类别: Optics; Physics, Applied
研究方向: Optics; Physics
IDS 号: 885AJ 
ISSN: 0946-2171 

第 179 条，共 210 条
标题: Selecting Key Poses on Manifold for Pairwise Action Recognition 
作者: Cao, XB (Cao, Xianbin); Ning, B (Ning, Bo); Yan, PK (Yan, Pingkun); Li, XL (Li, Xuelong)
来源出版物: IEEE TRANSACTIONS ON INDUSTRIAL INFORMATICS  卷: 8  期: 1  页: 168-177  DOI: 10.1109/TII.2011.2172452  出版年: FEB 2012  
Web of Science 核心合集中的 "被引频次": 14 
被引频次合计: 14 
摘要: In action recognition, bag of visual words based approaches have been shown to be successful, for which the quality of codebook is critical. In a large vocabulary of poses (visual words), some key poses play a more decisive role than others in the codebook. This paper proposes a novel approach for key poses selection, which models the descriptor space utilizing a manifold learning technique to recover the geometric structure of the descriptors on a lower dimensional manifold. A PageRank-based centrality measure is developed to select key poses according to the recovered geometric structure. In each step, a key pose is selected from the manifold and the remaining model is modified to maximize the discriminative power of selected codebook. With the obtained codebook, each action can be represented with a histogram of the key poses. To solve the ambiguity between some action classes, a pairwise subdivision is executed to select discriminative codebooks for further recognition. Experiments on benchmark datasets showed that our method is able to obtain better performance compared with other state-of-the-art methods.
文献类型: Article
作者关键词: Action recognition; bag of words; centrality measure; key poses; manifold leaning
KeyWords Plus: NONLINEAR DIMENSIONALITY REDUCTION; HUMAN MOTION; HUMAN MOVEMENT
Web of Science 类别: Automation & Control Systems; Computer Science, Interdisciplinary Applications; Engineering, Industrial
研究方向: Automation & Control Systems; Computer Science; Engineering
IDS 号: 881XZ 
ISSN: 1551-3203 

第 180 条，共 210 条
标题: Design of a Dual-Channel Mach-Zehnder Lateral Shearing Interferometer for the Large Aperture Static Imaging Spectrometer 
作者: Fu, Q (Fu Qiang); Xiangli, B (Xiangli Bin); Lu, QB (Lu Qun-bo); Jing, JJ (Jing Juan-juan)
来源出版物: SPECTROSCOPY AND SPECTRAL ANALYSIS  卷: 32  期: 2  页: 553-557  DOI: 10.3964/j.issn.1000-0593(2012)02-0553-05  出版年: FEB 2012  
Web of Science 核心合集中的 "被引频次": 1 
被引频次合计: 2 
摘要: Large aperture static imaging spectrometry (LASIS) is a kind of joint temporally and spatially modulated Fourier transform imaging spectrometry. In such instruments, lateral shearing interferometer is a key element, the most frequently used type of which is the Sagnac interferometer. In this configuration, one half of the light entering the interferometer backtracks and causes a great decrease in energy efficiency. The present paper proposes a modified Mach-Zehnder lateral shearing interferometer structure to tackle this problem. With the ability to produce the same lateral shear, it features the advantage of dual channel output. We present a ray tracing procedure to induce the general expression of the lateral shear as well as analyze the contributions of error sources to the shear accuracy. The results serve as a new idea for the design of large aperture static imaging spectrometers and can be used to instruct the design and optimization of this kind of imaging spectrometer.
文献类型: Article
作者关键词: Large aperture static imaging spectrometer; Fourier transform imaging spectrometer; Mach-Zehnder interferometer; Lateral shear
Web of Science 类别: Spectroscopy
研究方向: Spectroscopy
IDS 号: 883BB 
ISSN: 1000-0593 

第 181 条，共 210 条
标题: Robust lossless data hiding using clustering and statistical quantity histogram 
作者: An, LL (An, Lingling); Gao, XB (Gao, Xinbo); Yuan, Y (Yuan, Yuan); Tao, DC (Tao, Dacheng)
来源出版物: NEUROCOMPUTING  卷: 77  期: 1  页: 1-11  DOI: 10.1016/j.neucom.2011.06.012  出版年: FEB 1 2012  
Web of Science 核心合集中的 "被引频次": 12 
被引频次合计: 14 
摘要: Lossless data hiding methods usually fail to recover the hidden messages completely when the watermarked images are attacked. Therefore, the robust lossless data hiding (RLDH), or the robust reversible watermarking technique, is urgently needed to effectively improve the recovery performance. To date a couple of methods have been developed; however, they have such drawbacks as poor visual quality and low capacity. To solve this problem, we develop a novel statistical quantity histogram shifting and clustering-based RLDH method or SQH-SC for short. The benefits of SQH-SC in comparison with existing typical methods include: (1) strong robustness against lossy compression and random noise due to the usage of k-means clustering; (2) good imperceptibility and reasonable performance tradeoff due to the consideration of the just noticeable distortion of images; (3) high capacity due to the flexible adjustment of the threshold; and (4) wide adaptability and good stability to different kinds of images. Extensive experimental studies based on natural images, medical images, and synthetic aperture radar (SAR) images demonstrate the effectiveness of the proposed SQH-SC. (C) 2011 Published by Elsevier B.V.
文献类型: Article
作者关键词: Just noticeable distortion; k-Means clustering; Robust lossless data hiding; Statistical quantity histogram
KeyWords Plus: DIGITAL WATERMARKING; IMAGE WATERMARKING
Web of Science 类别: Computer Science, Artificial Intelligence
研究方向: Computer Science
IDS 号: 863ZI 
ISSN: 0925-2312 

第 182 条，共 210 条
标题: Learning optimal spatial filters by discriminant analysis for brain-computer-interface 
作者: Pang, YW (Pang, Yanwei); Yuan, Y (Yuan, Yuan); Wang, KQ (Wang, Kongqiao)
来源出版物: NEUROCOMPUTING  卷: 77  期: 1  页: 20-27  DOI: 10.1016/j.neucom.2011.07.016  出版年: FEB 1 2012  
Web of Science 核心合集中的 "被引频次": 9 
被引频次合计: 9 
摘要: Common Spatial Pattern (CSP) is one of the most widespread methods for Brain-Computer Interfaces (BCI), which is capable of enhancing the separability of the brain signals such as multi-channel electroencephalogram (EEG). CSP attempts to strengthen the separability by maximizing the variance of the spatially filtered signal of one class while minimizing it for another class. A straightforward way to improve the CSP is to employ the Fisher-Rao linear discriminant analysis (FLDA). But for the two-class scenario in BCI, FLDA merely result in as small as one filter. Experimental results have shown that the number of spatial filter is too small to achieve satisfying classification accuracy. Therefore, more than one filter is expected to get better performance. To deal with this difficulty, in this paper we propose to divide each class into many sub-classes (clusters) and formulate the problem in a re-designed graph embedding framework where the vertexes are cluster centers. We also reformulate the traditional FLDA in our graph embedding framework, which helps developing and understanding the proposed method. Experimental results demonstrate the advantages of the proposed method. (C) 2011 Elsevier B.V. All rights reserved.
文献类型: Article
作者关键词: Neural interfaces; Brain-computer interfaces; Common spatial pattern; EEG; Discriminant analysis
KeyWords Plus: NONLINEAR DIMENSIONALITY REDUCTION; MODEL; FRAMEWORK
Web of Science 类别: Computer Science, Artificial Intelligence
研究方向: Computer Science
IDS 号: 863ZI 
ISSN: 0925-2312 

第 183 条，共 210 条
标题: A method using long digital straight segments for fingerprint recognition 
作者: Jiang, XB (Jiang, Xiubao); You, XG (You, Xinge); Yuan, Y (Yuan, Yuan); Cong, MM (Cong, Mingming)
来源出版物: NEUROCOMPUTING  卷: 77  期: 1  页: 28-35  DOI: 10.1016/j.neucom.2011.07.018  出版年: FEB 1 2012  
Web of Science 核心合集中的 "被引频次": 0 
被引频次合计: 4 
摘要: In this paper, we proposed a new method using long digital straight segments (LDSSs) for fingerprint recognition based on such a discovery that LDSSs in fingerprints can accurately characterize the global structure of fingerprints. Different from the estimation of orientation using the slope of the straight segments, the length of LDSSs provides a measure for stability of the estimated orientation. In addition, each digital straight segment can be represented by four parameters: x-coordinate, y-coordinate, slope and length. As a result, only about 600 bytes are needed to store all the parameters of LDSSs of a fingerprint, as is much less than the storage orientation field needs. Finally, the LDSSs can well capture the structural information of local regions. Consequently. LDSSs are more feasible to apply to the matching process than orientation fields. The experiments conducted on fingerprint databases FVC2002 DB3a and DB4a show that our method is effective. (C) 2011 Elsevier B.V. All rights reserved.
文献类型: Article
作者关键词: Digital straight segment; Orientation field; Minutiae; Fingerprint recognition
KeyWords Plus: DIRECTIONAL FIELDS; SINGULAR POINTS; IMAGES; CLASSIFICATION; REPRESENTATION; VERIFICATION; COMPUTATION; EXTRACTION; ALGORITHM; MODELS
Web of Science 类别: Computer Science, Artificial Intelligence
研究方向: Computer Science
IDS 号: 863ZI 
ISSN: 0925-2312 

第 184 条，共 210 条
标题: Temporal contrast enhancement of picosecond pulses based on phase-conjugate wave generation 
作者: Liang, SG (Liang, S. G.); Liu, HJ (Liu, H. J.); Huang, N (Huang, N.); Sun, QB (Sun, Q. B.); Wang, YS (Wang, Y. S.); Zhao, W (Zhao, W.)
来源出版物: OPTICS LETTERS  卷: 37  期: 2  页: 241-243  出版年: JAN 15 2012  
Web of Science 核心合集中的 "被引频次": 2 
被引频次合计: 2 
摘要: A practical technique based on the phase-conjugate wave (PCW) generation is proposed to improve the temporal contrast of the picosecond pulses. Our theory predicts the temporal contrast of the picosecond pulses can be enhanced to about the cube of the temporal contrast of the input pulse via the PCW generation, in which the conversion efficiency from the incident pulse to the PCW is about 25%. In a proof-of-principle experiment, the temporal contrast of picosecond pulses was enhanced from 1.7 x 10(3) to 8.6 x 10(8) with the conversion efficiency of 10%. This technique is promising to effectively eliminate the background of the ultrashort and ultraintense laser pulses in the future. (C) 2012 Optical Society of America
PubMed ID: 22854480 
文献类型: Article
KeyWords Plus: FEMTOSECOND LASER-PULSES; SELF-DIFFRACTION; AMPLIFICATION
Web of Science 类别: Optics
研究方向: Optics
IDS 号: 885YY 
ISSN: 0146-9592 

第 185 条，共 210 条
标题: Dual-wavelength slightly off-axis digital holographic microscopy 
作者: Min, JW (Min, Junwei); Yao, BL (Yao, Baoli); Gao, P (Gao, Peng); Guo, RL (Guo, Rongli); Ma, BH (Ma, Baiheng); Zheng, JJ (Zheng, Juanjuan); Lei, M (Lei, Ming); Yan, SH (Yan, Shaohui); Dan, D (Dan, Dan); Duan, T (Duan, Tao); Yang, YL (Yang, Yanlong); Ye, T (Ye, Tong)
来源出版物: APPLIED OPTICS  卷: 51  期: 2  页: 191-196  出版年: JAN 10 2012  
Web of Science 核心合集中的 "被引频次": 7 
被引频次合计: 10 
摘要: We propose dual-wavelength digital holographic microscopy with a slightly off-axis configuration. The axial measurement range without phase ambiguity is extended to the micrometer range by synthesizing a beat wavelength between the two wavelengths with separation of 157 nm. Real-time measurement of the specimen is made possible by virtue of the high wavelength selectivity of the Bayer mosaic filtered color CCD camera. The principle of the method is exposed, and the practicability of the proposed configuration is demonstrated by the experimental results on a vortex phase plate and a rectangular phase step. (C) 2012 Optical Society of America
PubMed ID: 22270516 
文献类型: Article
KeyWords Plus: PHASE-SHIFTING INTERFEROMETRY; HYDROGEN RAMAN SHIFTER; CELLS; VISUALIZATION; RECOGNITION
Web of Science 类别: Optics
研究方向: Optics
IDS 号: 879EY 
ISSN: 1559-128X 
电子 ISSN: 2155-3165 

第 186 条，共 210 条
标题: Dual-channel phase-shifting interferometry for microscopy with second wavelength assistance 
作者: Zheng, JJ (Zheng, Juanjuan); Yao, BL (Yao, Baoli); Rupp, RA (Rupp, Romano A.); Ye, T (Ye, Tong); Gao, P (Gao, Peng); Min, JW (Min, Junwei); Guo, RL (Guo, Rongli)
来源出版物: CHINESE OPTICS LETTERS  卷: 10  期: 1  文献号: 010901  DOI: 10.3788/COL201210.010901  出版年: JAN 10 2012  
Web of Science 核心合集中的 "被引频次": 2 
被引频次合计: 2 
摘要: Dual-channel phase-shifting interferometry for simultaneous phase microscopy is presented. Red and blue light beams are used for microscope illumination. A 45 degrees tilted beamsplitter replicates the object and reference waves in red light together with the object wave in blue light into two parallel beams. The two resulting quadrature phase-shifting interferograms in red light and the object waves in blue light are generated in the two channels. The two interferograms are recorded simultaneously by a color charge-coupled device (CCD) camera, and can be separated via ROB components of the recorded color patterns without crosstalk. As a result, the phase of tested specimen can be retrieved. The feasibility of the proposed method is demonstrated by test performed on a microscopic specimen.
文献类型: Article
KeyWords Plus: DIGITAL HOLOGRAPHY; ALGORITHM; DYNAMICS; ELEMENT
Web of Science 类别: Optics
研究方向: Optics
IDS 号: 878IK 
ISSN: 1671-7694 

第 187 条，共 210 条
标题: Experimental observation of dissipative soliton resonance in an anomalous-dispersion fiber laser 
作者: Duan, LN (Duan, Lina); Liu, XM (Liu, Xueming); Mao, D (Mao, Dong); Wang, LR (Wang, Leiran); Wang, GX (Wang, Guoxi)
来源出版物: OPTICS EXPRESS  卷: 20  期: 1  页: 265-270  出版年: JAN 2 2012  
Web of Science 核心合集中的 "被引频次": 34 
被引频次合计: 35 
摘要: We have experimentally observed conventional solitons and rectangular pulses in an erbium-doped fiber laser operating at anomalous dispersion regime. The rectangular pulses exhibit broad quasi-Gaussian spectra (similar to 40 nm) and triangular autocorrelation traces. With the enhancement of pump power, the duration and energy of the output rectangular pulses almost increase linearly up to 330 ps and 3.2 nJ, respectively. It is demonstrated that high-energy pulses can be realized in anomalous-dispersion regime, and may be explained as dissipative soliton resonance. Our results have confirmed that the formation of dissipative soliton resonance is not sensitive to the sign of cavity dispersion. (C) 2011 Optical Society of America
PubMed ID: 22274349 
文献类型: Article
KeyWords Plus: NET-NORMAL-DISPERSION; REPETITION-RATE; GENERATION; PULSES; OSCILLATOR; ENERGY
Web of Science 类别: Optics
研究方向: Optics
IDS 号: 889OD 
ISSN: 1094-4087 

第 188 条，共 210 条
标题: Recent development of polymer/fullerene photovoltaic cells 
作者: Gao, BW (Gao Bo-Wen); Gao, C (Gao Chao); Que, WX (Que Wen-Xiu); Wei, W (Wei Wei)
来源出版物: ACTA PHYSICA SINICA  卷: 61  期: 19  文献号: 194213  DOI: 10.7498/aps.61.194213  出版年: 2012  
Web of Science 核心合集中的 "被引频次": 1 
被引频次合计: 1 
摘要: Polymer photovoltaic cells with organic polymer materials as the active layers for an increasing power conversion efficiency have become a research hotspot in the field of photovoltaic devices in recent years. In this paper, Internal mechanism of polymer/fullerene solar cells are elaborated exhaustively, including light absorption, exciton diffusion and dissociation and charge carrier transport as well as extraction. Furthermore, the optimization of device structure, morphology control and interface modification are introduced to improve performance of polymer/fullerene solar cells. Power conversion efficiency and the various structures which can be achieved are discussed in detail. The future prospects of polymer photovoltaic cells are also expected.
文献类型: Article
作者关键词: bulk-heterojunction; polymer; fullerene; inverted solar cells
KeyWords Plus: POLYMER SOLAR-CELLS; BULK-HETEROJUNCTION; HIGH-PERFORMANCE; PHASE-SEPARATION; EFFICIENCY; MORPHOLOGY; ACCEPTOR; DONOR; NETWORK; IMPROVE
Web of Science 类别: Physics, Multidisciplinary
研究方向: Physics
IDS 号: 047LC 
ISSN: 1000-3290 

第 189 条，共 210 条
标题: Technology of polarization interference imaging spectral based on pupil division and angle shear 
作者: Tang, Q (Tang Qian); Zhao, BC (Zhao Bao-Chang); Qiu, YH (Qiu Yue-Hong); Zhang, CM (Zhang Chun-Min); Mu, TK (Mu Ting-Kui)
来源出版物: ACTA PHYSICA SINICA  卷: 61  期: 23  文献号: 230701  DOI: 10.7498/aps.61.230701  出版年: 2012  
Web of Science 核心合集中的 "被引频次": 2 
被引频次合计: 2 
摘要: With the combination of pupil division, Wollaston prism angle shear and Savart plate lateral shear interference, a new technology that can aquire the message of imaging, polarization and spectrum simultaneously is presented. The system works at the pushing mode with neither mechanical movable nor electrically tunable device, and four quarters of the single charge-coupled device can get four interferograms of different polarization states (two polarization-difference spectral imagings). The device is discussed in detail, and the relationship between azimuth of the prism principal cross section and the output light intensity is analyzed, and then system parameters are optimized In the paper, we derive the interference fringe intensity distribution formula, use computer numerical simulation to verify the feasibility and accuracy of this method, and thus provide an important theory basis and the practice instruction for designing a new type of imaging spectrometer and its engineering applications.
文献类型: Article
作者关键词: new optical sensing technology; technology of imaging polarization spactrum; Wollaston prism; Savart plate
KeyWords Plus: POLARIMETRY; SPECTROPOLARIMETER; SPECTROMETER; COMPACT; INTERFEROMETER; OPHTHALMOLOGY; FIELD
Web of Science 类别: Physics, Multidisciplinary
研究方向: Physics
IDS 号: 114IG 
ISSN: 1000-3290 

第 190 条，共 210 条
标题: Dispersion control in fiber-coupled THz-TDS 
作者: Liu, J (Liu, Jia); Fan, WH (Fan, Wenhui); Xue, B (Xue, Bing)
来源出版物: OPTIK  卷: 123  期: 24  页: 2230-2232  DOI: 10.1016/j.ijleo.2011.11.002  出版年: 2012  
Web of Science 核心合集中的 "被引频次": 0 
被引频次合计: 0 
摘要: To construct a compact THz-TDS system equipped with movable emitter and receiver heads, a specific fiber-delivery system is developed to deliver ultra-short pulses from Ti: sapphire laser through a single-mode fiber. Hence, how to manage the dispersion in fiber-delivery system efficiently becomes one of the most important issues to be solved. In this paper, the theoretical calculation of dispersion in fiber-delivery system was discussed initially. And also, a pair of gratings, which can generate negative group velocity dispersion (GVD), was introduced to compensate the positive dispersion in fiber. A minimum temporal width of pulse about 60 fs was measured at the end of the fiber-delivery system by optimizing the relative position of gratings. The experimental result agreed well to the theoretical calculation and demonstrated the advantages of the fiber-delivery system. Crown Copyright (C) 2011 Published by Elsevier GmbH. All rights reserved.
文献类型: Article
作者关键词: THz-TDS; Dispersion; GVD; Gratings; Pulse width
KeyWords Plus: TERAHERTZ; SPECTROSCOPY
Web of Science 类别: Optics
研究方向: Optics
IDS 号: 065KG 
ISSN: 0030-4026 

第 191 条，共 210 条
标题: Double-mode refraction-type time-of-flight momentum (energy) mapping analyzer: Generalized theory 
作者: Wang, C (Wang, Chao); Kang, YF (Kang, Yifan); Tian, JS (Tian, Jinshou)
来源出版物: OPTIK  卷: 123  期: 24  页: 2241-2246  DOI: 10.1016/j.ijleo.2011.10.034  出版年: 2012  
Web of Science 核心合集中的 "被引频次": 0 
被引频次合计: 0 
摘要: Generalized theory about the double-mode refraction-type time-of-Flight momentum (energy) mapping analyzer is presented, which was inaccurately termed as reflection-type one and partially discussed in our previous material published in Optik (Ref. [9]). Key issues of operation modes classification of o mode and e mode, the specific condition and salient features for each of them, and magnetic field choosing are detailed, together with some corrections on that Optik material. The provided example verifies the theory. (C) 2011 Elsevier GmbH. All rights reserved.
文献类型: Article
作者关键词: Time-of-flight spectrometer; Double-mode; Refraction-type; Momentum mapping
KeyWords Plus: MASS-SPECTROMETER; RESOLUTION
Web of Science 类别: Optics
研究方向: Optics
IDS 号: 065KG 
ISSN: 0030-4026 

第 192 条，共 210 条
标题: Stability in a general coupled laser array 
作者: Zhou, L (Zhou, Liang); Duan, KL (Duan, Kailiang)
来源出版物: OPTIK  卷: 123  期: 23  页: 2187-2190  DOI: 10.1016/j.ijleo.2011.10.020  出版年: 2012  
Web of Science 核心合集中的 "被引频次": 0 
被引频次合计: 0 
摘要: For the first time we have presented a method to investigate the stability of quiescent state in a coupled laser array. By introducing tiny perturbation, stability of quiescent state can be known by investigating eigenvalues of coefficient matrix of the corresponding linear differential equations. Only when real parts of the eigenvalues were all negative or zero, the corresponding quiescent state is stable. Two tapes of coupled laser array with loop and linear topological structure were studied respectively. It was found that there were innumerable quiescent states and they could be divided into several types based on phase relation. Some types were stable and others were unstable. Topological structure affects the stability of quiescent state in a coupled laser array. (C) 2011 Elsevier GmbH. All rights reserved.
文献类型: Article
作者关键词: Coupled laser array; Quiescent state; Stability; Perturbation
KeyWords Plus: CHAOS; SYNCHRONIZATION; COHERENCE
Web of Science 类别: Optics
研究方向: Optics
IDS 号: 056DR 
ISSN: 0030-4026 

第 193 条，共 210 条
标题: Theoretical analysis of response characteristics for the large exponential-doping transmission-mode GaAs photocathodes 
作者: Cai, ZP (Cai Zhi-Peng); Yang, WZ (Yang Wen-Zheng); Tang, WD (Tang Wei-Dong); Hou, X (Hou Xun)
来源出版物: ACTA PHYSICA SINICA  卷: 61  期: 18  文献号: 187901  DOI: 10.7498/aps.61.187901  出版年: 2012  
Web of Science 核心合集中的 "被引频次": 2 
被引频次合计: 2 
摘要: A new-type GaAs photocathode with ultrafast time response, that is, the large exponential-doping transmission-mode GaAs photocathode, is discussed in detail. The response characteristics, including quantum yield, time and spatial resolution, are numerically simulated. The analysis results show that the transit response time of the photo-excited electrons for the GaAs photocathode is extremely shortened, because the built-in electric field in GaAs layer formed by the large exponential-doping mode is benefitcial to the photoelectron transport process of GaAs photocathodes. The response time can reach about 10 ps when the thickness of GaAs dgorption layer is around, which shows that the novel NEA cathode has a better feature of temporal response than that of traditional GaAs photocathode. In addition, the quantum yield will reach similar to 10%-20% in the whole special response range, and the spatial resolution is improved obviously. The analysis results indicate that with high quantum efficiency guaranteed, the large exponential-doping NEA cathode overcomes the limitation of time response of traditional GaAs NEA cathode and improves the spatial resolution, which indicates that the new NEA cathode is expected to meet the demands of high-speed device and photoelectron device, and promote the further development and applications of NEA cathodes.
文献类型: Article
作者关键词: large exponential-doping; built-in electric field; quantum yield; time and spatial resolution
Web of Science 类别: Physics, Multidisciplinary
研究方向: Physics
IDS 号: 047JQ 
ISSN: 1000-3290 

第 194 条，共 210 条
标题: Multi-channel biosensor based on photonic crystal waveguide and microcavities 
作者: Yun, MJ (Yun, Maojin); Wan, Y (Wan, Yong); Liang, J (Liang, Jian); Xia, F (Xia, Feng); Liu, ML (Liu, Meiling); Ren, LY (Ren, Liyong)
来源出版物: OPTIK  卷: 123  期: 21  页: 1920-1922  DOI: 10.1016/j.ijleo.2011.09.024  出版年: 2012  
Web of Science 核心合集中的 "被引频次": 2 
被引频次合计: 2 
摘要: An ultrasensitive two-dimensional photonic crystal biosensor is theoretically demonstrated in this paper. Such device consists of a waveguide and high Q-value microcavities which are realized by introducing line and point defects into the photonic crystal respectively. The band structures and the transmission spectra are obtained from the Finite-Difference -Time-Domain (FDTD) method. The simulation results showed that such device is strongly sensitive to the refractive index of the analyte injected into the point defect. The designed device can be applied for measurements of the refractive index and detection of protein-concentrations. (C) 2011 Elsevier GmbH. All rights reserved.
文献类型: Article
作者关键词: Optical sensor; Photonic crystal; Waveguide; Microcavity; FDTD
KeyWords Plus: SURFACE-PLASMON RESONANCE; LABEL-FREE
Web of Science 类别: Optics
研究方向: Optics
IDS 号: 043ER 
ISSN: 0030-4026 

第 195 条，共 210 条
标题: Fabrication and Characteristic of Polarization-Maintaining Photonic Crystal Fiber with Two Big Air Holes Structure 
作者: Xue, XM (Xue, Xiaomin); Li, WN (Li, Weinan); Wang, PF (Wang, Pengfei); Lu, M (Lu, Min)
来源出版物: FIBER AND INTEGRATED OPTICS  卷: 31  期: 5  页: 316-327  DOI: 10.1080/01468030.2012.712609  出版年: 2012  
Web of Science 核心合集中的 "被引频次": 0 
被引频次合计: 0 
摘要: In this article, polarization-maintaining photonic crystal fibers with two big air holes, which are based on a kind of multi-component glass, are fabricated by the capillary-stacking and drawing method. The microstructure of the small air holes is found to be well kept through a scanning electron microscope, even with a diameter close to 0.6 mu m. Numerical results show that the chromatic dispersion of the proposed fiber with a 125-mu m-diameter approaches zero at 1,550 nm. Meanwhile, experimental results display that the beat length of the same photonic crystal fiber is 3.6961 mm at 1,550 nm, and the related polarization extinction ratio and polarization mode dispersionis 17.23889 dB and 2.58321 ps, respectively.
文献类型: Article
作者关键词: fabrication; measurements; photonic crystal fiber; polarization maintaining
KeyWords Plus: MODE HOLEY; DEFECT; UNIT
Web of Science 类别: Optics
研究方向: Optics
IDS 号: 030SK 
ISSN: 0146-8030 

第 196 条，共 210 条
标题: Fast computation for generating CGH of a 3D object by employing connections between layers 
作者: Tang, C (Tang, Chuang); Yao, BL (Yao, Baoli)
来源出版物: JOURNAL OF MODERN OPTICS  卷: 59  期: 16  页: 1406-1409  DOI: 10.1080/09500340.2012.715691  出版年: 2012  
Web of Science 核心合集中的 "被引频次": 0 
被引频次合计: 0 
摘要: An approximate method for generating computer-generated holograms (CGH) of a 3D object with six times faster speed than the conventional algorithm is presented. In the conventional algorithm, a 3D object is sliced into many layers and treated as a collection of self-illuminated point light source. The propagation process of a light ray from every point of an object to all the points on the hologram plane is simulated and interfered with by the reference beam to form a CGH. In our proposed method, under the assumption that the depth of a 3D object is much smaller than the recording distance, we just need to calculate the oblique distance between the first layer and the hologram plane, and then the oblique distances from the other layers to the hologram plane can be obtained from a simple relation, thus the computational time is much reduced. The CGH is optically reconstructed and the quality of the reconstructed image agrees well with that from the conventional algorithm.
文献类型: Article
作者关键词: fast computation; 3D object; CGH; reconstruction image
KeyWords Plus: FRONT-RECORDING PLANE; LOOK-UP TABLE; FRESNEL HOLOGRAMS; 3-DIMENSIONAL DISPLAY; CALCULATION ALGORITHM; COMPUTER
Web of Science 类别: Optics
研究方向: Optics
IDS 号: 017OV 
ISSN: 0950-0340 

第 197 条，共 210 条
标题: Wave-front curvature compensation of polarization phase-shifting digital holography 
作者: Min, JW (Min, Junwei); Yao, BL (Yao, Baoli); Gao, P (Gao, Peng); Ma, BH (Ma, Baiheng); Yan, SH (Yan, Shaohui); Peng, F (Peng, Fei); Zheng, JJ (Zheng, Juanjuan); Ye, T (Ye, Tong); Rupp, R (Rupp, Romano)
来源出版物: OPTIK  卷: 123  期: 17  页: 1525-1529  DOI: 10.1016/j.ijleo.2011.09.018  出版年: 2012  
Web of Science 核心合集中的 "被引频次": 1 
被引频次合计: 1 
摘要: An on-axis polarization phase-shifting digital holographic microscope, based on a normal upright optical microscope, is constructed to quantitatively measure both the amplitude and phase distributions of specimen. The condenser lens and microscope objective employed in the object beam path enhance the illumination and magnification of the image, however, they induce additional phase aberration of the object wave. The physical formation of the phase aberration is theoretically analyzed, and a formula for the object wave front involving the phase aberration in the CCD plane is derived. The phase aberration can be eliminated in the reconstruction procedure by measuring a specimen-free hologram and then fitting the aberration phase with a least square ellipsoidal model to determine the parameters of the system. This phase aberration compensation procedure also reduces some of noises in the reconstructed phase of the specimen. The practicability of this method is demonstrated by a test experiment on microlenses. (c) 2011 Elsevier GmbH. All rights reserved.
文献类型: Article
作者关键词: Digital holography; Polarization phase-shifting; Aberration compensation
KeyWords Plus: ABERRATION COMPENSATION; MICROSCOPY
Web of Science 类别: Optics
研究方向: Optics
IDS 号: 003PY 
ISSN: 0030-4026 

第 198 条，共 210 条
标题: Widely tunable Tm:LuYAG laser with a volume Bragg grating 
作者: Sun, M (Sun, M.); Long, JY (Long, J. Y.); Li, XH (Li, X. H.); Liu, Y (Liu, Y.); Ma, HF (Ma, H. F.); An, Y (An, Y.); Hu, XH (Hu, X. H.); Wang, YS (Wang, Y. S.); Li, C (Li, C.); Shen, DY (Shen, D. Y.)
来源出版物: LASER PHYSICS LETTERS  卷: 9  期: 8  页: 553-556  DOI: 10.7452/lapl.201210028  出版年: 2012  
Web of Science 核心合集中的 "被引频次": 3 
被引频次合计: 3 
摘要: Widely tunable operation of a mixed crystal Tm:(LuxY1-x)(3)Al5O12 (Tm:LuYAG) laser is reported using a volume Bragg grating (VBG) as the wavelength selective component. The operating wavelength was continuously tunable from 1935.3 to 1994.9 nm (corresponding to a tuning range of similar to 60 nm), and a maximum output power of 1.76 W at 1999.7 nm was obtained for a launched pump power of 10.75 W with the VBG used at normal incidence. (C) 2012 by Astro, Ltd.
文献类型: Article
作者关键词: tunable laser; volume Bragg grating; mixed laser crystal
KeyWords Plus: OPTICAL PARAMETRIC OSCILLATOR; PUMPED TM-YAG; FIBER LASER; HIGH-POWER; PERFORMANCE; CRYSTALS; EFFICIENT; YB
Web of Science 类别: Optics; Physics, Applied
研究方向: Optics; Physics
IDS 号: 968HW 
ISSN: 1612-2011 

第 199 条，共 210 条
标题: Mode-locked thulium-doped fiber laser with a narrow bandwidth and high pulse energy 
作者: Zhou, W (Zhou, W.); Shen, DY (Shen, D. Y.); Wang, YS (Wang, Y. S.); Long, JY (Long, J. Y.); An, Y (An, Y.)
来源出版物: LASER PHYSICS LETTERS  卷: 9  期: 8  页: 587-590  DOI: 10.7452/lapl.201210039  出版年: 2012  
Web of Science 核心合集中的 "被引频次": 1 
被引频次合计: 1 
摘要: We have demonstrated a mode-locked thulium-doped fiber laser with a narrow bandwidth and high pulse energy using a semiconductor saturable absorption mirror (SESAM). The laser generates sub-nanosecond pulses with a repetition rate of 39.8 MHz, average power of 150 mW, pulse energy of 3.8 nJ and spectrum width of 2 nm which should be attractive for pump sources to generate mid-infrared. To the best of our knowledge, this is the first report on a 2 mu m mode-locked fiber-oscillator with a narrow spectral width and highest pulse energy in the all-anomalous-dispersion regime. (C) 2012 by Astro, Ltd.
文献类型: Article
作者关键词: fiber lasers; thulium-doped fiber; passively mode-locking; narrow bandwidth
KeyWords Plus: REPETITION RATE; TM; OSCILLATOR; DISPERSION; ABSORBER
Web of Science 类别: Optics; Physics, Applied
研究方向: Optics; Physics
IDS 号: 968HW 
ISSN: 1612-2011 

第 200 条，共 210 条
标题: Luminescence properties of Nd3+-doped LaF3 nanocrystals with a long lifetime in organic solvents 
作者: Sun, WX (Sun, Wenxiu); Cui, XX (Cui, Xiaoxia); Wang, ZY (Wang, Zhongyue); Wei, W (Wei, Wei); Peng, B (Peng, Bo)
来源出版物: JOURNAL OF MATERIALS CHEMISTRY  卷: 22  期: 14  页: 6990-6993  DOI: 10.1039/c2jm15891d  出版年: 2012  
Web of Science 核心合集中的 "被引频次": 8 
被引频次合计: 9 
摘要: A kind of monodisperse LaF3:Nd nanocrystal with a small size and long lifetime in solvent was synthesized via a hydrothermal process. The crystalline phase, morphology, and luminescence properties were characterized using X-ray diffraction (XRD), transmission electron microscopy (TEM), emission spectroscopy as well as dynamic decays. The results indicated that LaF3: Nd nanocrystals with a size below 30 nm have great dispersity in various solvents. An excellent lifetime of 359 mu s was detected in a transparent DMSO-tetrabromoethane dispersion. It suggested that these nanocrystals could have great applications in biological and optical amplification fields.
文献类型: Article
KeyWords Plus: RARE-EARTH IONS; NANOPARTICLES; EMISSION; FLUORESCENCE; INTENSITIES; CONVERSION; SPECTRA; ND3+
Web of Science 类别: Chemistry, Physical; Materials Science, Multidisciplinary
研究方向: Chemistry; Materials Science
IDS 号: 907ZL 
ISSN: 0959-9428 

第 201 条，共 210 条
标题: FREQUENCY-SELECTIVE NANOSTRUCTURED PLASMONIC ABSORBER BY HIGHLY LOSSY INTERFACE MODE 
作者: Gong, Y (Gong, Y.); Li, K (Li, K.); Huang, J (Huang, J.); Copner, NJ (Copner, N. J.); Davies, A (Davies, A.); Wang, L (Wang, L.); Duan, T (Duan, T.)
来源出版物: PROGRESS IN ELECTROMAGNETICS RESEARCH-PIER  卷: 124  页: 511-525  DOI: 10.2528/PIER11121903  出版年: 2012  
Web of Science 核心合集中的 "被引频次": 3 
被引频次合计: 3 
摘要: We report on an existence of a highly lossy interface mode (HLIM) in a designed plasmonic nanostructure for perfect absorption of the incident optical waves. Interactions between the single thin-metallic-layer (TML) and slits arrays for excitation of the HLIM in the proposed plasmonic absorber are investigated, and eigenfrequency formula for the HLIM is derived. Analytical and numerical results show that the HLIM is frequency-selective, opens a narrow and steep absorption band in photonic stopband of the slits arrays. Due to the HLIM lossy characteristic, surface plasmon polaritons are significantly trapped at the TML interface with absorption close to 100%.
文献类型: Article
KeyWords Plus: INSENSITIVE METAMATERIAL ABSORBER; SENSITIZED SOLAR-CELLS; WIDE INCIDENT ANGLE; WAVE-GUIDES; METAL; GRATINGS
Web of Science 类别: Engineering, Electrical & Electronic; Physics, Applied; Telecommunications
研究方向: Engineering; Physics; Telecommunications
IDS 号: 897JA 
ISSN: 1559-8985 

第 202 条，共 210 条
标题: Influence of the wavefront mismatch, spatial chirp and multimode pump on the beam quality of OPCPA 
作者: Sun, QB (Sun, Qibing); Liu, HJ (Liu, Hongjun); Huang, N (Huang, Nan); Zhao, W (Zhao, Wei)
来源出版物: JOURNAL OF MODERN OPTICS  卷: 59  期: 7  页: 628-635  DOI: 10.1080/09500340.2011.648222  出版年: 2012  
Web of Science 核心合集中的 "被引频次": 0 
被引频次合计: 0 
摘要: The beam quality and wavefront distribution of the optical parametric chirped-pulse amplification (OPCPA) front-end system of the petawatt laser has become a focus for research. The influence of wavefront mismatch, spatial chirp and multimode pump on the beam quality of OPCPA is numerically simulated and analyzed. It is shown that the beam quality and wavefront distribution becomes worse as the mismatch angle or the order of the spatial chirp increases. Meanwhile, it is also found that the beam quality and conversion efficiency of the amplified signal becomes worse as the transverse distribution of the pump laser descends.
文献类型: Article
作者关键词: beam quality; OPCPA; wavefront mismatch; wavefront distribution; spatial chirp
KeyWords Plus: PULSE AMPLIFICATION SYSTEM; OPTICAL PARAMETRIC AMPLIFICATION; HIGH-CONTRAST; LASER SYSTEM; GENERATION; AMPLIFIER; TERAWATT; ENERGY; DESIGN
Web of Science 类别: Optics
研究方向: Optics
IDS 号: 907RH 
ISSN: 0950-0340 

第 203 条，共 210 条
标题: All-optical logic gates based on photoinduced anisotropy of bacteriorhodopsin film 
作者: Han, JH (Han, Junhe); Yao, BL (Yao, Baoli); Gao, P (Gao, Peng); Chen, LJ (Chen, Liju); Huang, MJ (Huang, Mingju)
来源出版物: JOURNAL OF MODERN OPTICS  卷: 59  期: 7  页: 636-642  DOI: 10.1080/09500340.2011.652202  出版年: 2012  
Web of Science 核心合集中的 "被引频次": 0 
被引频次合计: 0 
摘要: All-optical logic gates based on photoinduced anisotropy of bacteriorhodopsin (BR) film are proposed. The photoinduced anisotropy in BR film, which arises from the selective absorption of BR molecules to polarized light, can be controlled by changing the amplitudes and polarizations of exiting beams. As a consequence, the polarization of the probe light passing through the BR film can be controlled by the polarization of the exiting beam. Based on this property, a novel scheme of all-optical logic gates, such as AND, OR, XOR and NOT, has been implemented via the pump-probe technique. A theoretical model for the all-optical logic gates is proposed, and the theoretical predictions are demonstrated with the experimental results.
文献类型: Article
作者关键词: all-optical logic gate; bacteriorhodopsin film; photoinduced anisotropy
KeyWords Plus: POLARIZATION; HOLOGRAPHY; KINETICS; PROTEIN; LIGHT
Web of Science 类别: Optics
研究方向: Optics
IDS 号: 907RH 
ISSN: 0950-0340 

第 204 条，共 210 条
标题: Characterization of stable brush-shaped large-volume plasma generated at ambient air 
作者: Tang, J (Tang, Jie); Cao, WQ (Cao, Wenqing); Zhao, W (Zhao, Wei); Wang, YS (Wang, Yishan); Duan, YX (Duan, Yixiang)
来源出版物: PHYSICS OF PLASMAS  卷: 19  期: 1  文献号: 013501  DOI: 10.1063/1.3672511  出版年: JAN 2012  
Web of Science 核心合集中的 "被引频次": 9 
被引频次合计: 9 
摘要: A brush-shaped, large-volume plasma was generated at ambient pressure with a dc power supply and flowing argon gas, as well as a narrow outlet slit. Based on the V-I curve and emission profiles obtained in our experiment, the plasma shows some typical glow discharge characteristics. The electron density in the positive column close to the anode is about 1.4 x 10(14)cm(-3) high, which is desirable for generating abundant amounts of reactive species in the plasma. Emission spectroscopy diagnosis indicates that many reactive species, such as excited argon atoms, excited oxygen atoms, excited nitrogen molecules, OH and C-2 radicals, etc., generated within the plasma are distributed symmetrically and uniformly, which is preferable to some chemical reactions in practical applications. Spectral measurement also shows that the concentration of some excited argon atoms increases with the argon flow rate when the applied voltage is unvaried, while that of these excited argon atoms declines with the discharge current in the normal/subnormal glow discharge mode with the argon flow rate fixed. The plasma size is about 15 mm x 1 mm x 19 mm (L, W, H), when 38-W of discharge power is used. Such a laminar brush-shaped large-volume plasma device ensures not only efficient utilization of the plasma gas, but also effective processing of objects with large volume and complicated structure that are susceptible to high temperatures. (C) 2012 American Institute of Physics. [doi: 10.1063/1.3672511]
文献类型: Article
KeyWords Plus: ATMOSPHERIC-PRESSURE; EMISSION-SPECTRA; GLOW-DISCHARGES; ARGON; MICROPLASMAS
Web of Science 类别: Physics, Fluids & Plasmas
研究方向: Physics
IDS 号: 901IF 
ISSN: 1070-664X 

第 205 条，共 210 条
标题: X-ray photon counting detector for x-ray pulsar-based navigation 
作者: Hu, HJ (Hu Hui-Jun); Zhao, BS (Zhao Bao-Sheng); Sheng, LZ (Sheng Li-Zhi); Yan, QR (Yan Qiu-Rong); Chen, BM (Chen Bao-Mei); Wang, P (Wang Peng)
来源出版物: ACTA PHYSICA SINICA  卷: 61  期: 1  文献号: 019701  出版年: JAN 2012  
Web of Science 核心合集中的 "被引频次": 5 
被引频次合计: 7 
摘要: A prototype of x-ray photon counting detector is proposed for x-ray pulsar navigation. The detector consists of CsI photocathode, micro-channel plate (MCP) electron multiplier, collect anode and electronic readout. The sensitivity, the temporal resolution, and the dead time are tested, and the results show that the sensitivity of the detector is 5.2 x 10(3) A/W at 5 keV, the temporal resolution is 1.1 ns, and dead time is 100 ns.
文献类型: Article
作者关键词: pulsar navigation; photon counting detector; sensitivity; temporal resolution
KeyWords Plus: IMAGING-SYSTEM
Web of Science 类别: Physics, Multidisciplinary
研究方向: Physics
IDS 号: 879VB 
ISSN: 1000-3290 

第 206 条，共 210 条
标题: All-optical format conversion from non-return-to-zero to return-to-zero based on four-wave mixing in photonic crystal fiber 
作者: Hui, ZQ (Hui Zhan-Qiang); Zhang, JG (Zhang Jian-Guo)
来源出版物: ACTA PHYSICA SINICA  卷: 61  期: 1  文献号: 014217  出版年: JAN 2012  
Web of Science 核心合集中的 "被引频次": 2 
被引频次合计: 2 
摘要: The conversion from all-optical non-return-to-zero (NRZ) to return-to-zero (RZ) format is a crucial technology in interfacing WDM and OTDM of future transparent photonic network. The conversion from all-optical single-to-dual NRZ to RZ format conversion is presented and experimentally demonstrated based on four-wave mixing (FWM) in a 50 m dispersion-flattened highly-nonlinear photon crystal fiber (DF-HNL-PCF). The original NRZ format is converted into RZ format by injecting synchronized clock signal into the DF-HNL-PCF. The FWM effect generates two sideband components, which carry the same data information as the original NRZ signal with RZ format. The proposed format converter has a wide and tunable operation wavelength range of 19.3 nm. The optimum conversion efficiency, extinct ratio and Q factor are -21 dB, 11.9 dB and 7.2, respectively. The system is transparent to both bit rate and modulation format. The advantage of this scheme consists in the ability of bandwidth scalable due to the fact that the dispersion flattening of HNL - PCF is used. Furthermore, it is all optical fiber, compact and robust, which makes it more competitive as well as easily accessible for use in practical optical communication systems.
文献类型: Article
作者关键词: all-optical format conversion; four-wave mixing (MP-FWM); photonic crystal fiber (PCF)
KeyWords Plus: NONLINEAR POLARIZATION ROTATION; WAVELENGTH CONVERSION; CHANNEL NRZ; WDM; AMPLIFIER; SWITCH; PUMP; OTDM; SOA
Web of Science 类别: Physics, Multidisciplinary
研究方向: Physics
IDS 号: 879VB 
ISSN: 1000-3290 

第 207 条，共 210 条
标题: Research on the Interlaced Encoding Pixels in Hadamard Transform Spectral Imager Based on DMD 
作者: Xu, J (Xu Jun); Hu, BL (Hu Bing-liang); Feng, DZ (Feng Da-zheng); Zhang, W (Zhang Wen); Yan, P (Yan Peng)
来源出版物: SPECTROSCOPY AND SPECTRAL ANALYSIS  卷: 32  期: 1  页: 278-282  DOI: 10.3964/j.issn.1000-0593(2012)01-0278-05  出版年: JAN 2012  
Web of Science 核心合集中的 "被引频次": 1 
被引频次合计: 2 
摘要: The key innovation in Hadamard transform spectral imager (HTSI) introduced recently is the use of digital micro-mirror device (DMD) to encode spectral information. However, it brings some new problems for us to solve synchronously. An interlaced encoding phenomenon caused by the application of DMD to our HTSI was investigated and analyzed. These interlaced encoding pixels were not encoded based on Hadamard transform; therefore they should be processed specially in spectrum recovery. To improve the quality of the recovered spectral images, a positioning method and a decoding method for the interlaced encoding pixels were proposed. In our experiment, we first directed a beam of laser into our HTSI to fill the field of view and labeled the positions of the interlaced encoding pixels. Then we recorded two groups of the encoded images of the target by changing the positions of all the encoding channels on the DMD. The interlaced encoding pixels could be distinguished easily by observing the number of non-zero constants and zero elements in a column vector which is made up of the gray values of a pixel of the encoded images in sequence. The interlaced encoding pixels of the first group of the encoded images turned into the normal Hadamard encoding pixels of the second group of the encoded images. The interlaced encoding pixels of the first group of the encoded images can be decoded through applying inverse Hadamard transform to the corresponding pixels of the second group of the encoded images. The experimental results prove the feasibility of the decoding method.
文献类型: Article
作者关键词: Hadamard transform; DMD; Spectral imager; Interlaced encoding; Positioning method; Decoding method
Web of Science 类别: Spectroscopy
研究方向: Spectroscopy
IDS 号: 873RI 
ISSN: 1000-0593 

第 208 条，共 210 条
标题: Supercontinuum generation in standard single-mode fiber pumped by a nanosecond-pulse laser 
作者: Liu, XM (Liu, X. M.); Wang, LR (Wang, L. R.); Mao, D (Mao, D.); Duan, LN (Duan, L. N.)
来源出版物: LASER PHYSICS  卷: 22  期: 1  页: 227-231  DOI: 10.1134/S1054660X11230113  出版年: JAN 2012  
Web of Science 核心合集中的 "被引频次": 3 
被引频次合计: 3 
摘要: We have experimentally investigated supercontinuum generation in a conventional single-mode fiber pumped with a nanosecond pulse source. The experimental results show that, when pump power increases, the spectral flatness is improved obviously and the spectral broadening only occurs in a red-shifted radiation rather than a blue-shifted radiation. A supercontinuum source is experimentally reported with a flatness of 4.7 dB over 180 nm (ranging from 1555 to > 1735 nm) at pump power P (R) = 5 W and is predicted to have the flatness of less than 1 dB at P (R) > 8 W. The cascade of stimulated Raman scattering (SRS) together with soliton fission plays the key roles in supercontinuum generation.
文献类型: Article
KeyWords Plus: PHOTONIC CRYSTAL FIBERS; DISPERSION-SHIFTED FIBERS; GLASS
Web of Science 类别: Optics; Physics, Applied
研究方向: Optics; Physics
IDS 号: 874YI 
ISSN: 1054-660X 

第 209 条，共 210 条
标题: One-dimensional optical materials of microfibers by electrospinning 
作者: Li, L (Li, Le); Yang, XH (Yang, Xinghua); Yuan, LB (Yuan, Libo)
来源出版物: MATERIALS LETTERS  卷: 66  期: 1  页: 292-295  DOI: 10.1016/j.matlet.2011.08.068  出版年: JAN 2012  
Web of Science 核心合集中的 "被引频次": 2 
被引频次合计: 2 
摘要: Optical microfibers of PMMA were fabricated by electrospinning. The fibers with the diameter ranging from 300 nm to 1000 nm were obtained by electrospinning the solutions such as PMMA/DMF, PMMA/DMF/formic acid and PMMA/formic acid. The morphology and the diameter of the fibers were analyzed by scanning electron microscopy (SEM). Results showed that the sidewalls of the fibers were smooth and the diameters were uniform. The light with the wavelength of 488 nm, 532 nm and 650 nm could be launched into the fibers and guide along them. The simulation and experimental results showed that the fibers exhibited excellent optical properties. This method provided an effective and convenient way to fabricate highly uniform micro/nano scale optical waveguide neither using expensive equipments nor involving complex procedures. (C) 2011 Elsevier B.V. All rights reserved.
文献类型: Article
作者关键词: Electrospinning; Optical materials and properties; Fiber technology; Micro or nanofiber
KeyWords Plus: COMPOSITE NANOFIBERS; FABRICATION; FIBER; FIELD
Web of Science 类别: Materials Science, Multidisciplinary; Physics, Applied
研究方向: Materials Science; Physics
IDS 号: 856RE 
ISSN: 0167-577X 

第 210 条，共 210 条
标题: The stress relief mechanism in laser irradiating on porous films 
作者: Xia, ZL (Xia, Zhilin); Wang, H (Wang, Hu); Xu, Q (Xu, Qi)
来源出版物: OPTICS COMMUNICATIONS  卷: 285  期: 1  页: 70-76  DOI: 10.1016/j.optcom.2011.09.012  出版年: JAN 1 2012  
Web of Science 核心合集中的 "被引频次": 3 
被引频次合计: 3 
摘要: Stress relief effect is believed to be the main reason why the porous structure films have high laser induced damage threshold. But there is little systematic theoretical investigation of this view. This essay adopts spherical coordinate model to calculate the temperature and stress distribution in the film and analyzes the local stress redistribution after phase transformation or crush happens. The influences of porosity and pore radius on stress redistribution have been studied. The results show that: for the case of only local crush occurrence, the changes of porosity and pore radius have little influence on the stress relief effect For the films with low porosity, the formed thermal stress cannot be alleviated effectively. When local phase transformation happens, the permeation action of high pressure fluid can reduce the local high pressure in the phase transformation zone: on the other hand, it can make the high pressure fluid permeate to film's surface and cause surface tensile stress increase. The final effect is the competitive result of these two mechanisms. Overall, when the permeation action of phase transformation materials happens, the higher porosity or larger pore radius, the higher capability of films to resist laser damage. (C) 2011 Elsevier B.V. All rights reserved.
文献类型: Article
作者关键词: Stress relief; Porous materials; Laser induced damage
KeyWords Plus: OPTICAL COATINGS; DAMAGE
Web of Science 类别: Optics
研究方向: Optics
IDS 号: 850YC 
ISSN: 0030-4018