2015

• Record 385 of
  
  Title:Wideband slow light in microfiber double-knot resonator with a parallel structure
  
  Author(s):Xu, Yi-Ping(1); Ren, Li-Yong(1); Liang, Jian(1); Ma, Cheng-Ju(1); Wang, Ying-Li(1); Kong, Xu-Dong(1); Lin, Xiao(1)
  Source: Journal of Applied Physics  Volume: 118  Issue: 7  DOI: 10.1063/1.4928967  Published: August 21, 2015  
  Abstract:The characteristics of slow light in the microfiber double-knot resonator with a parallel structure are investigated both theoretically and experimentally. It is predicted that a wide bandwidth of about 20 GHz and flat-top group delay of about 70 ps can be generated in this resonator by changing the coupling coefficient. In the experiment, such a resonator was fabricated and the slow-light effect was demonstrated. As a result, when a pulse with a bandwidth of 3.35 GHz (equivalent to the temporal width of 299 ps) was launched into the resonator, a large group delay, whose average value was about 69.4 ps with a flat-top wavelength bandwidth of about 190 pm, was achieved. © 2015 AIP Publishing LLC.
  Accession Number: 20153501207782
• Record 386 of
  
  Title:Mode-matching and fringe locking technique in preparation of squeezed states of light
  
  Author(s):Qu, Wenyan(1); Feng, Fei(1); Song, Jiazheng(1); Zhang, Tongyi(1)
  Source: Hongwai yu Jiguang Gongcheng/Infrared and Laser Engineering  Volume: 44  Issue: 9  DOI:   Published: September 25, 2015  
  Abstract:Optical parametric oscillation is the critical part in the preparation of squeezed states of light. The mode-matching and fringe locking technique should be employed to improve the stability of the optical parametric oscillator cavity. How the mode-matching efficiency influence the squeezing degree of the squeezed light and the locking accuracy of the fringe locking technique were analyzed theoretically. Then the fringe locking technique was employed to stabilize the optical parametric oscillator cavity after the mode-matching between the laser mode and the fundamental mode of the cavity. The theoretical and experimental results show that a perfect mode-matching would improve the squeezing degree and the locking accuracy of the fringe locking technique, when the mode-matching is optimized, the length variance of the cavity is 7.35 nm and the locking time is no less than 2 h, which is sufficient for the detection of the squeezed states of light. ©, 2015, Editorial Board of Journal of Infrared and Laser Engineering. All right reserved.
  Accession Number: 20154501520704
• Record 387 of
  
  Title:Various soliton molecules in large anomalous dispersion fiber laser
  
  Author(s):Han, Xiaoxiang(1); Liu, Xueming(1)
  Source: 2015 11th Conference on Lasers and Electro-Optics Pacific Rim, CLEO-PR 2015  Volume: 2  Issue:   DOI: 10.1109/CLEOPR.2015.7376110  Published: January 7, 2016  
  Abstract:Soliton molecules (SMs) induced by the spectral filtering with the phase difference of 0, π, π/2 and multiple separations are observed. It is found that the equilibrium distances of SMs are multiple and discrete. © 2015 IEEE.
  Accession Number: 20161502242261
• Record 388 of
  
  Title:Investigation on terahertz generation by controlling the laser spot size on photoconductive antenna
  
  Author(s):Li, Hui(1); Fan, Wenhui(1); Liu, Jia(1)
  Source: Hongwai yu Jiguang Gongcheng/Infrared and Laser Engineering  Volume: 44  Issue: 2  DOI:   Published: February 25, 2015  
  Abstract:It was experimentally investigated that the laser spot size on photoconductive antenna (PCA) gap could have a great influence on terahertz (THz) generation. Moreover, the simulation on THz generation influenced by the laser power density was carried out, which was agreed well to the experiments. It is well demonstrated that the increase of laser power density on PCA gap can enhance THz generation. However, the intensity of THz radiation reached saturation while the laser power density exceeding a certain value. The laser power density increased further by focusing harder, but the THz radiation was getting weaker due to the smaller laser excited area on PCA gap. ©, 2015, Chinese Society of Astronautics. All right reserved.
  Accession Number: 20151800809861
• Record 389 of
  
  Title:Diffusion emission model for solid-state photon-enhanced thermionic emission solar energy converters
  
  Author(s):Yang, Yang(1); Yang, Wenzheng(1); Sun, Chuandong(1)
  Source: Materials Science in Semiconductor Processing  Volume: 35  Issue:   DOI: 10.1016/j.mssp.2015.03.002  Published: July 2015  
  Abstract:Solid-state photon-enhanced thermionic emission (PETE) solar energy converters are new devices that can directly convert solar energy into electrical power at elevated temperatures. This study proposes a new solid-state PETE device structure with a p-type doped semiconductor as the absorber. A model based on a 1D steady-state continuity equation is presented to simulate the diffusion and emission of photogenerated carriers and to calculate the efficiencies. This model can evaluate the effect of device structure and material parameters on performance and efficiency. Calculation results show that the new device is more efficient compared with the original device. A longer electron diffusion length is favourable for enhancing efficiency. Moreover, the optimal absorber thickness is predicted. Our analyses also show that the front interface strongly affects conversion efficiency, which emphasises the need to reduce interface recombination losses. The results of this study may serve as bases for the optimum design of practical solid-state PETE devices. © 2015 Elsevier Ltd.
  Accession Number: 20151200668507
• Record 390 of
  
  Title:Carbon-nanotube-based passively mode-locked fiber lasers modulated with sub-loop
  
  Author(s):Cui, Yudong(1)
  Source: Optik  Volume: 126  Issue: 6  DOI: 10.1016/j.ijleo.2015.02.002  Published: March 1, 2015  
  Abstract:We have proposed a carbon-nanotube-based passively mode-locked fiber laser, which consists of two fiber ring resonators, for the first time to author's best knowledge. The proposed laser in the main cavity is coupled with a fiber sub-loop, which is connected with a 2 × 2 optical coupler. Without the sub-loop, uniform-spaced conventional solitons are achieved in the fiber ring laser. With the sub-loop, the fiber laser generates a train of pulses modulated with a periodic envelop. The modulation period and pulse-pulse separation are ∼160 and ∼4.3 ns, which are determined by the lengths of the main cavity and the sub-loop, respectively. © 2015 Elsevier GmbH. All rights reserved.
  Accession Number: 20151700778586
• Record 391 of
  
  Title:Switchable linear-cavity nanotube-mode-locking fiber laser emitting picosecond or femtosecond pulses
  
  Author(s):Yao, Xiankun(1)
  Source: Optics Communications  Volume: 335  Issue:   DOI: 10.1016/j.optcom.2014.09.036  Published: 15 January 2015  
  Abstract:A switchable linear-cavity nanotube-mode-locking fiber laser is proposed by exploiting fiber Bragg grating for the first time to the author's best knowledge. The proposed all-fiber laser can deliver either picosecond or femtosecond pulses by controlling the polarization controllers. The durations of picosecond and femtosecond pulses are 16.4 ps and 838 fs with the central wavelengths of 1529.5 and 1560 nm, respectively. The femtosecond pulse has symmetrical spectrum sidebands, but the picosecond pulse almost has no spectral sidebands. Our work provides a simple, low-cost, dual-scale pulse source for practical applications. © 2014 Elsevier B.V. All rights reserved.
  Accession Number: 20144500163611
• Record 392 of
  
  Title:Switchable dual-wavelength all-fiber laser mode-locked by carbon nanotubes
  
  Author(s):Kong, Y.C.(1); Yang, H.R.(1); Li, W.L.(1); Chen, G.W.(1)
  Source: Laser Physics  Volume: 25  Issue: 1  DOI: 10.1088/1054-660X/25/1/015101  Published: January 1, 2015  
  Abstract:We have proposed a compact dual-wavelength all-fiber pulse laser based on a single-walled carbon nanotube and chirped fiber Bragg gratings (CFBGs). A transmission filter is composed of a circulator and two CFBGs and is capable of controlling the operation of the proposed fiber laser. Mode-locking operations can be switched between 1551.2 and 1548.6 nm with the appropriate adjustment of polarization controller. Our laser delivers the pulses with the spectral bandwidth of about 0.6 nm and the pulse duration of about 7 ps. This work provides a low-cost, stable, and dual-wavelength ultrafast-pulsed laser source suitable for practical applications. © 2015 Astro Ltd.
  Accession Number: 20145300389156
• Record 393 of
  
  Title:Quadruple-wavelength tunable and dual-wavelength switchable ultrafast fiber laser
  
  Author(s):Chen, G.W.(1); Cui, Y.D.(1)
  Source: Laser Physics  Volume: 25  Issue: 5  DOI: 10.1088/1054-660X/25/5/055103  Published: May 1, 2015  
  Abstract:We propose a quadruple-wavelength tunable and dual-wavelength switchable ultrafast fiber laser by incorporating four fiber Bragg gratings. The tunable operations depend on the losses induced by intracavity polarization controllers. By appropriately setting the states of PCs, quadruple-wavelength picosecond solitons can be realized at 1530, 1540, 1550 and 1560 nm, respectively. When the losses are suitable, solitons with two different wavelengths can reach the gain balance, and the dual-wavelength operations are switched among the four wavelengths. These results demonstrate that the proposed fiber laser offers potential opportunities in exploiting flexibly switchable multi-wavelength pulse sources. © 2015 Astro Ltd.
  Accession Number: 20151800807603
• Record 394 of
  
  Title:LD side-pumped passive mode-locked Nd:YAG laser with semiconductor saturable absorption mirror
  
  Author(s):Wang, Xi(1); Wang, Yong-Gang(1); Duan, Li-Na(1); Li, Lu(1); Wang, Yi-Shan(1)
  Source: Guangzi Xuebao/Acta Photonica Sinica  Volume: 44  Issue: 7  DOI: 10.3788/gzxb20154407.0714001  Published: July 1, 2015  
  Abstract:In order to obtain picoseconds pulse output, a Nd:YAG laser passively mode-locked was proposed by a reflective semiconductor saturable-absorber mirror. Based on Z-type resonator, the laser output was obtained with repetition frequency of 101 MHz, pulses of 23.4 ps, central wavelength of 1064 nm and average power of 356 mW, corresponding to 3.49 nJ pulse energy. The measured beam quality is about 1.2.In order to enhance the average single pulse energy of mode-locked pulse, Q-switched mode-locking operation was obtained by inserting an acousto-optic Q-switch, producing 364 mW pulses with 1.03 MHz repetition rate. The resulting 406 nJ pulse energy is 116 times larger than that from continuous mode-locking operation. ©, 2015, Chinese Optical Society. All right reserved.
  Accession Number: 20153201119612
• Record 395 of
  
  Title:Observation of dual-wavelength solitons and bound states in a nanotube/microfiber mode-locking fiber laser
  
  Author(s):Zeng, C.(1); Cui, Y.D.(1); Guo, J.(1)
  Source: Optics Communications  Volume: 347  Issue:   DOI: 10.1016/j.optcom.2015.02.054  Published: July 2015  
  Abstract:We report on the experimental observation of dual-wavelength soliton and the phase-locked bound state in an all-fiber laser mode-locked by a carbon nanotubes/microfiber saturable absorber. The operation wavelengths are strongly dependent on the intracavity loss. By adjusting an attenuator to increase the intracavity loss, mode-locking wavelength shifts from 1557 to 1531 nm. With the appropriate pump power and intracavity loss, dual-wavelength solitons are achieved simultaneously. In addition, the phase-locked bound-state solitons are also observed at the two wavelengths. The pulse separation and phase difference are related to the first-order Kelly sidebands. © 2015 Elsevier B.V. All rights reserved.
  Accession Number: 20151000618620
• Record 396 of
  
  Title:Tunable multiple phase-coupled plasmoninduced transparencies in graphene metamaterials
  
  Author(s):Zeng, Chao(1); Cui, Yudong(1); Liu, Xueming(1)
  Source: Optics Express  Volume: 23  Issue: 1  DOI: 10.1364/OE.23.000545  Published: January 12, 2015  
  Abstract:We demonstrate the existence of multiple electromagnetically induced transparencies (EIT)-like spectral responses in graphene metamaterials consisting of a series of self-assembled graphene Fabry-Pérot (FP) cavities. By exploiting the graphene plasmon resonances and phase-coupling effects, the transfer matrix model is established to theoretically predict the EIT-like responses, and the calculated results coincide well with numerical simulations. It is found that high-contrast (∼90%) multiple EIT-like windows are observed over a broad range of mid-infrared. Additionally, these optical responses can be efficiently tuned by altering the Fermi level in graphene and the separations of FP cavities. The proposed scheme paves the way toward control of the multiple EIT-like responses, enabling exploration of the on-chip multifunctional electro-optic devices including multi-channel-selective filters, sensors, and modulators. © 2014 Optical Society of America.
  Accession Number: 20152901047212