2024

• Record 313 of
  
  Title:Repetition rate tuning and locking of solitons in a microrod resonator
  
  Author Full Names:Niu, Rui; Wan, Shuai; Sun, Shu-Man; Ma, Tai-Gao; Chen, Hao-Jing; Wang, Wei-Qiang; Lu, Zhizhou; Zhang, Wen-Fu; Guo, Guang-Can; Zou, Chang-Ling; Dong, Chun-Hua

  Source Title:OPTICS LETTERS

  Language:English

  Document Type:Article

  Keywords Plus:FREQUENCY COMBS; GENERATION

  Abstract:Recently, there has been significant interest in the generation of coherent temporal solitons in optical microresonators. In this Letter, we present a demonstration of dissipative Kerr soliton generation in a microrod resonator using an addition, we are able to control the repetition rate of the soliton over a range of 200 kHz while maintaining the pump laser frequency, by applying external stress tuning. Through the precise control of the PZT voltage, we achieve a stability level of 3.9 x 10(-10) for residual fluctuation of the repetition rate when averaged 1 s. Our platform offers precise tuning and locking capabilities for the repetition frequency of coherent mode-locked combs in microresonators. This advancement holds great potential for applications in spectroscopy and precision measurements. (c) 2024 Optica Publishing Group

  Addresses:[Niu, Rui; Wan, Shuai; Sun, Shu-Man; Ma, Tai-Gao; Chen, Hao-Jing; Guo, Guang-Can; Zou, Chang-Ling; Dong, Chun-Hua] Chinese Acad Sci, Univ Sci & Technol China, Key Lab Quantum Informat, Hefei 230026, Anhui, Peoples R China; [Niu, Rui; Wan, Shuai; Sun, Shu-Man; Chen, Hao-Jing; Guo, Guang-Can; Zou, Chang-Ling; Dong, Chun-Hua] Univ Sci & Technol China, CAS Ctr Excellence Quantum Informat & Quantum Phys, Hefei 230026, Anhui, Peoples R China; [Wang, Wei-Qiang; Lu, Zhizhou; Zhang, Wen-Fu] Chinese Acad Sci, State Key Lab Transient Opt & Photon, Xian Inst Opt & Precis Mech XIOPM, Xian 710119, Peoples R China; [Wang, Wei-Qiang; Lu, Zhizhou; Zhang, Wen-Fu] Univ Chinese Acad Sci, Beijing 100049, Peoples R China

  Affiliations:Chinese Academy of Sciences; University of Science & Technology of China, CAS; CAS Center for Excellence in Quantum Information & Quantum Physics; Chinese Academy of Sciences; University of Science & Technology of China, CAS; CAS Center for Excellence in Quantum Information & Quantum Physics; State Key Laboratory of Transient Optics & Photonics; Chinese Academy of Sciences; Xi'an Institute of Optics & Precision Mechanics, CAS; Chinese Academy of Sciences; University of Chinese Academy of Sciences, CAS

  Publication Year:2024

  Volume:49

  Issue:3

  Start Page:570

  End Page:573

  DOI Link:http://dx.doi.org/10.1364/OL.511339

  数据库ID（收录号）:WOS:001171657400009
• Record 314 of
  
  Title:Atom-referenced and stabilized soliton microcomb
  
  Author Full Names:Niu, Rui; Wan, Shuai; Hua, Tian-Peng; Wang, Wei-Qiang; Wang, Zheng-Yu; Li, Jin; Wang, Zhu-Bo; Li, Ming; Shen, Zhen; Sun, Yu Robert; Hu, Shui-Ming; Little, Brent E.; Chu, Sai Tak; Zhao, Wei; Guo, Guang-Can; Zou, Chang-Ling; Xiao, Yun-Feng; Zhang, Wen-Fu; Dong, Chun-Hua

  Source Title:SCIENCE CHINA-PHYSICS MECHANICS & ASTRONOMY

  Language:English

  Document Type:Article

  Keywords Plus:MICRORESONATOR SOLITONS; PHOTONIC CHIP; TRANSMISSION; GENERATION; CRYSTALS

  Abstract:For the applications of the frequency comb in microresonators, it is essential to obtain a fully frequency-stabilized microcomb laser source. In this study, we present a system for generating a fully atom-referenced stabilized soliton microcomb. The pump light around 1560.48 nm is locked to an ultra-low-expansion (ULE) cavity. This pump light is then frequency-doubled and referenced to the atomic transition of 87Rb. The repetition rate of the soliton microcomb is injection-locked to an atomic-clock-stabilized radio frequency (RF) source, leading to mHz stabilization at 1 s. As a result, all comb lines have been frequency-stabilized based on the atomic reference and the ULE cavity, achieving a very high precision of approximately 18 Hz at 1 s, corresponding to the frequency stability of 9.5 x 10-14. Our approach provides a fully stabilized microcomb experiment scheme with no requirement of f-2f technique, which could be easily implemented and generalized to various photonic platforms, thus paving the way towards the ultraprecise optical sources for high precision spectroscopy.

  Addresses:[Wang, Wei-Qiang; Little, Brent E.; Zhao, Wei; Zhang, Wen-Fu] Chinese Acad Sci, State Key Lab Transient Opt & Photon, Xian Inst Opt & Precis Mech, Xian 710119, Peoples R China; [Niu, Rui; Wan, Shuai; Wang, Zheng-Yu; Li, Jin; Wang, Zhu-Bo; Li, Ming; Shen, Zhen; Guo, Guang-Can; Zou, Chang-Ling; Dong, Chun-Hua] Univ Sci & Technol China, CAS Key Lab Quantum Informat, Hefei 230026, Peoples R China; [Niu, Rui; Wan, Shuai; Hua, Tian-Peng; Wang, Zheng-Yu; Li, Jin; Wang, Zhu-Bo; Li, Ming; Shen, Zhen; Sun, Yu Robert; Hu, Shui-Ming; Guo, Guang-Can; Zou, Chang-Ling; Dong, Chun-Hua] Univ Sci & Technol China, CAS Ctr Excellence Quantum Informat & Quantum Phys, Hefei 230026, Peoples R China; [Wang, Wei-Qiang; Little, Brent E.; Zhao, Wei; Zhang, Wen-Fu] Univ Chinese Acad Sci, Beijing 100049, Peoples R China; [Sun, Yu Robert; Hu, Shui-Ming] Univ Sci & Technol China, Dept Chem Phys, Hefei 230026, Peoples R China; [Chu, Sai Tak] City Univ Hong Kong, Dept Phys, Dept Mat Sci & Engn, Hong Kong 999077, Peoples R China; [Xiao, Yun-Feng] Peking Univ, Frontiers Sci Ctr Nanooptoelectron, Sch Phys, State Key Lab Mesoscop Phys, Beijing 100871, Peoples R China

  Affiliations:Chinese Academy of Sciences; Xi'an Institute of Optics & Precision Mechanics, CAS; State Key Laboratory of Transient Optics & Photonics; Chinese Academy of Sciences; University of Science & Technology of China, CAS; CAS Center for Excellence in Quantum Information & Quantum Physics; Chinese Academy of Sciences; University of Science & Technology of China, CAS; CAS Center for Excellence in Quantum Information & Quantum Physics; Chinese Academy of Sciences; University of Chinese Academy of Sciences, CAS; Chinese Academy of Sciences; University of Science & Technology of China, CAS; City University of Hong Kong; Peking University

  Publication Year:2024

  Volume:67

  Issue:2

  Article Number:224262

  DOI Link:http://dx.doi.org/10.1007/s11433-023-2234-6

  数据库ID（收录号）:WOS:001129657300001
• Record 315 of
  
  Title:Wavefront Reconstruction Using Two-Frame Random Interferometry Based on Swin-Unet
  
  Author Full Names:Shu, Xindong; Li, Baopeng; Ma, Zhen

  Source Title:PHOTONICS

  Language:English

  Document Type:Article

  Keywords Plus:FRINGE-PATTERN; PHASE

  Abstract:Due to its high precision, phase-shifting interferometry (PSI) is a commonly used optical component detection method in interferometers. However, traditional PSI, which is susceptible to environmental factors, is costly, with piezoelectric ceramic transducer (PZT) being a major contributor to the high cost of interferometers. In contrast, two-frame random interferometry does not require precise multiple phase shifts, which only needs one random phase shift, reducing control costs and time requirements, as well as mitigating the impact of environmental factors (mechanical vibrations and air turbulence) when acquiring multiple interferograms. A novel method for wavefront reconstruction using two-frame random interferometry based on Swin-Unet is proposed. Besides, improvements have been made on the basis of the established algorithm to develop a new wavefront reconstruction method named Phase U-Net plus (PUN+). According to training the Swin-Unet and PUN+ with a large amount of simulated data generated by physical models, both of the methods accurately compute the wrapped phase from two frames of interferograms with an unknown phase step (except for multiples of pi). The superior performance of both methods is effectively showcased by reconstructing phases from both simulated and real interferograms, in comprehensive comparisons with several classical algorithms. The proposed Swin-Unet outperforms PUN+ in reconstructing the wrapped phase and unwrapped phase.

  Addresses:[Shu, Xindong; Li, Baopeng; Ma, Zhen] Chinese Acad Sci, Xian Inst Opt & Precis Mech, Xian 710119, Peoples R China; [Shu, Xindong] Univ Chinese Acad Sci, Beijing 100049, Peoples R China

  Affiliations:Chinese Academy of Sciences; Xi'an Institute of Optics & Precision Mechanics, CAS; Chinese Academy of Sciences; University of Chinese Academy of Sciences, CAS

  Publication Year:2024

  Volume:11

  Issue:2

  Article Number:122

  DOI Link:http://dx.doi.org/10.3390/photonics11020122

  数据库ID（收录号）:WOS:001172415000001
• Record 316 of
  
  Title:Enhanced Up-Conversion Emission of NaGdF4: Yb3+/Eu3+ Crystal via Li+ Doping for Anti-Counterfeiting Application
  
  Author Full Names:Wang Chong; Ren Zhong-xuan; Li Dong-dong; She Jiang-bo

  Source Title:SPECTROSCOPY AND SPECTRAL ANALYSIS

  Language:Chinese

  Document Type:Article

  Keywords Plus:LUMINESCENCE; NANOPARTICLES; ER

  Abstract:Rare earth luminescent materials have gradually become a research hotspot in fluorescence anti-counterfeiting because of their high purity of luminous color, long fluorescent life, stable physical-chemical properties, and low toxicity. A series of NaGdF4:Yb3+/Eu3+ microcrystals co-doped with various Li+ concentrations were synthesized by the hydrothermal method in this paper. The samples' morphology, size, and up-conversion luminescence properties were analyzed by X-ray diffraction (XRD), scanning electron microscopy (SEM), up-conversion emission spectroscopy, and fluorescence lifetime tests. The crystal with strong luminous intensity was further applied to anti-counterfeiting identification. It shows that all the diffraction peaks of NaGdF4:Yb3+/Eu3+/Li+ microcrystals are consistent with the standard-NaGdF4 card. No impurity peak was found in the XRD pattern. The hexagonal NaGdF4:Yb3+/Eu3+/Li+ with high purity and crystallinity was synthesized. The SEM image of the crystal shows that the generated sample is a pure hexagonal phase, with uniform distribution, and no reunion. Co-doped Yb3+/Eu3+/Li+ has little effect on crystal structure, morphology and size. It can be seen from the up-conversion emission spectrum that the green luminescence intensity of 15 mol% Li+ doped NaGdF4:Yb3+/Eu3+ crystal is 6 times higher than that of the undoped Li+ sample. Adjust the power range of the laser to 0.8 similar to 2.2 W and observe the change in UCL intensity of the samples doped with 0 mol% Li+ and 15 mol% Li+. It can be observed that with the increase of pump power, the up-conversion intensity gradually increases. The number of photons required to generate the up-conversion luminescence n is close to 2, indicating that the emission process of the sample is a two-photon process. The fluorescence lifetime of the D-5(1) level in the sample is about 1.4 times that of the undoped one. Finally, the NaGdF4 : 0.2Yb/0.02Eu/0.15Li crystal with uniform morphology and strong luminous intensity was further applied as fluorescent ink. Screen printing technology printed The fluorescent anti-counterfeiting patterns on paper, glass and plastic. The pattern emitted bright green light under the pumping of a 980 nm laser. In the natural environment, the anti-counterfeiting pattern on the paper has good concealment. The word safe lenght is 5.5 mm, and the spacing between letters is 0.5 mm. The boundaries between letters are clear and easy to distinguish under 980 nm excitation. The plastic printed with the anti-counterfeiting pattern was exposed to the outdoor natural environment for a month, and the pattern did not change significantly. It shows that the anti-counterfeiting pattern made of NaGdF4 : 0.2Yb/0.02Eu/0.15Li has a high resolution, is easy to identify, and is less affected by the environment, and has excellent application prospects in anti-counterfeiting identification.

  Addresses:[Wang Chong; Ren Zhong-xuan; Li Dong-dong] Xian Univ Posts & Telecommun, Sch Elect Engn, Xian 710121, Peoples R China; [Ren Zhong-xuan; She Jiang-bo] Chinese Acad Sci, Xian Inst Opt & Precis Mech, State Key Lab Transient Opt & Photon, Xian 710119, Peoples R China

  Affiliations:Xi'an University of Posts & Telecommunications; State Key Laboratory of Transient Optics & Photonics; Chinese Academy of Sciences; Xi'an Institute of Optics & Precision Mechanics, CAS

  Publication Year:2024

  Volume:44

  Issue:2

  Start Page:497

  End Page:503

  DOI Link:http://dx.doi.org/10.3964/j.issn.1000-0593(2024)02-0497-07

  数据库ID（收录号）:WOS:001202623000029
• Record 317 of
  
  Title:Methodology and Modeling of UAV Push-Broom Hyperspectral BRDF Observation Considering Illumination Correction
  
  Author Full Names:Wang, Zhuo; Li, Haiwei; Wang, Shuang; Song, Liyao; Chen, Junyu

  Source Title:REMOTE SENSING

  Language:English

  Document Type:Article

  Keywords Plus:REFLECTANCE; SENSOR

  Abstract:The Bidirectional Reflectance Distribution Function (BRDF) is a critical spatial distribution parameter in the quantitative research of remote sensing and has a wide range of applications in radiometric correction, elemental inversion, and surface feature estimation. As a new means of BRDF modeling, UAV push-broom hyperspectral imaging is limited by the push-broom imaging method, and the multi-angle information is often difficult to obtain. In addition, the random variation of solar illumination during UAV low-altitude flight makes the irradiance between different push-broom hyperspectral rows and different airstrips inconsistent, which significantly affects the radiometric consistency of BRDF modeling and results in the difficulty of accurately portraying the three-dimensional spatial reflectance distribution in the UAV model. These problems largely impede the application of outdoor BRDF. Based on this, this paper proposes a fast multi-angle information acquisition scheme with a high-accuracy BRDF modeling method considering illumination variations, which mainly involves a lightweight system for BRDF acquisition and three improved BRDF models considering illumination corrections. We adopt multi-rectangular nested flight paths for multi-gray level targets, use multi-mode equipment to acquire spatial illumination changes and multi-angle reflectivity information in real-time, and introduce the illumination correction factor K through data coupling to improve the kernel, Hapke, and RPV models, and, overall, the accuracy of the improved model is increased by 20.83%, 11.11%, and 31.48%, respectively. The results show that our proposed method can acquire multi-angle information quickly and accurately using push-broom hyperspectral imaging, and the improved model eliminates the negative effect of illumination on BRDF modeling. This work is vital for expanding the multi-angle information acquisition pathway and high-efficiency and high-precision outdoor BRDF modeling.

  Addresses:[Wang, Zhuo; Li, Haiwei; Wang, Shuang; Chen, Junyu] Chinese Acad Sci, Xian Inst Opt & Precis Mech CAS, Key Lab Spectral Imaging Technol, Xian 710119, Peoples R China; [Wang, Zhuo] Univ Chinese Acad Sci, Beijing 100049, Peoples R China; [Wang, Shuang] Shaanxi Key Lab Opt Remote Sensing & Intelligent I, Xian 710100, Peoples R China; [Song, Liyao] Xian Technol Univ, Inst Artificial Intelligence & Data Sci, Xian 710021, Peoples R China

  Affiliations:Chinese Academy of Sciences; Xi'an Institute of Optics & Precision Mechanics, CAS; Chinese Academy of Sciences; University of Chinese Academy of Sciences, CAS; Xi'an Technological University

  Publication Year:2024

  Volume:16

  Issue:3

  Article Number:543

  DOI Link:http://dx.doi.org/10.3390/rs16030543

  数据库ID（收录号）:WOS:001160492200001
• Record 318 of
  
  Title:Coherence analysis of supercontinuum generation in nitrobenzene liquid-core photonic crystal fiber based on adaptive step-size methods
  
  Author Full Names:Wen, Jin; Liang, Bozhi; Sun, Wei; He, Chenyao; Xiong, Keyu; Yu, Huimin; Zhang, Hui; Wu, Zhengwei; Wang, Qian

  Source Title:OPTICAL AND QUANTUM ELECTRONICS

  Language:English

  Document Type:Article

  Abstract:Methods for solving the generalized nonlinear Schrodinger equation (GNLSE) with adaptive step-size methods including the local error method (LEM) and conservation quantity error method (CQEM) are described. Supercontinuum generation (SCG) in liquid-core photonic crystal fibers (PCF) is numerically simulated by using LEM and CQEM in the time domain and frequency domain (FD) respectively. According to the numerical simulation results, the advantages and disadvantages of different adaptive step-size methods are compared, and the influence of different adaptive step-size methods on the coherence of SC is analyzed. A supercontinuum (SC) spectrum spanning from approximately 1300-2800 nm with high-coherence properties is numerically generated in the 5 cm fiber with 50 fs and 1000 W pump pulses at 1.55 mu m. The numerical results demonstrate that the performance of the SC generated in FD is also better because the nonlinear operator is more effective in FD. In addition, the pulse evolution process based on LEM is smoother and the coherence is better due to its higher number of iterations and accuracy, so it is adapted to accurately modeling the SCG in PCF. However, the CQEM is more computationally efficient and can minimize the computational effort, so it is suitable for the fast modeling of SCG in PCF. This numerical study helps to optimize the numerical process of SCG and find a new way for the generation of highly coherent SC.

  Addresses:[Wen, Jin; Liang, Bozhi; Sun, Wei; He, Chenyao; Xiong, Keyu; Yu, Huimin; Zhang, Hui; Wu, Zhengwei; Wang, Qian] Xian Shiyou Univ, Sch Sci, Xian 710065, Peoples R China; [Wen, Jin] Chinese Acad Sci, State Key Lab Transient Opt & Photon, Xian 710019, Peoples R China

  Affiliations:Xi'an Shiyou University; Chinese Academy of Sciences; State Key Laboratory of Transient Optics & Photonics

  Publication Year:2024

  Volume:56

  Issue:4

  Article Number:619

  DOI Link:http://dx.doi.org/10.1007/s11082-023-06267-6

  数据库ID（收录号）:WOS:001154859300008
• Record 319 of
  
  Title:Fourier Ptychographic Microscopy 10 Years on: A Review
  
  Author Full Names:Xu, Fannuo; Wu, Zipei; Tan, Chao; Liao, Yizheng; Wang, Zhiping; Chen, Keru; Pan, An

  Source Title:CELLS

  Language:English

  Document Type:Review

  Keywords Plus:BLOOD-CELL COUNT; HIGH-RESOLUTION; HIGH-THROUGHPUT; NEURAL-NETWORK; WIDE-FIELD; DIFFRACTION TOMOGRAPHY; PHASE DETERMINATION; IMAGING-SYSTEM; HEART-DISEASE; RECONSTRUCTION

  Abstract:Fourier ptychographic microscopy (FPM) emerged as a prominent imaging technique in 2013, attracting significant interest due to its remarkable features such as precise phase retrieval, expansive field of view (FOV), and superior resolution. Over the past decade, FPM has become an essential tool in microscopy, with applications in metrology, scientific research, biomedicine, and inspection. This achievement arises from its ability to effectively address the persistent challenge of achieving a trade-off between FOV and resolution in imaging systems. It has a wide range of applications, including label-free imaging, drug screening, and digital pathology. In this comprehensive review, we present a concise overview of the fundamental principles of FPM and compare it with similar imaging techniques. In addition, we present a study on achieving colorization of restored photographs and enhancing the speed of FPM. Subsequently, we showcase several FPM applications utilizing the previously described technologies, with a specific focus on digital pathology, drug screening, and three-dimensional imaging. We thoroughly examine the benefits and challenges associated with integrating deep learning and FPM. To summarize, we express our own viewpoints on the technological progress of FPM and explore prospective avenues for its future developments.

  Addresses:[Xu, Fannuo; Wu, Zipei; Tan, Chao; Liao, Yizheng; Wang, Zhiping; Chen, Keru; Pan, An] Chinese Acad Sci, Xian Inst Opt & Precis Mech, State Key Lab Transient Opt & Photon, Xian 710119, Peoples R China; [Xu, Fannuo; Liao, Yizheng; Pan, An] Univ Chinese Acad Sci, Beijing 100049, Peoples R China; [Wu, Zipei] Shenzhen Univ, Sch Phys & Optoelect Engn, Shenzhen 518060, Peoples R China; [Tan, Chao] Sichuan Univ, Sch Elect & Informat Engn, Chengdu 610065, Peoples R China; [Wang, Zhiping] Lanzhou Univ, Sch Phys Sci & Technol, Lanzhou 730000, Peoples R China; [Chen, Keru] Xi An Jiao Tong Univ, Sch Automat Sci & Engn, Xian 710049, Peoples R China

  Affiliations:State Key Laboratory of Transient Optics & Photonics; Chinese Academy of Sciences; Xi'an Institute of Optics & Precision Mechanics, CAS; Chinese Academy of Sciences; University of Chinese Academy of Sciences, CAS; Shenzhen University; Sichuan University; Lanzhou University; Xi'an Jiaotong University

  Publication Year:2024

  Volume:13

  Issue:4

  Article Number:324

  DOI Link:http://dx.doi.org/10.3390/cells13040324

  数据库ID（收录号）:WOS:001175251200001
• Record 320 of
  
  Title:Design of Optical System for Ultra-Large Range Line-Sweep Spectral Confocal Displacement Sensor
  
  Author Full Names:Yang, Weiguang; Du, Jian; Qi, Meijie; Yan, Jiayue; Cheng, Mohan; Zhang, Zhoufeng

  Source Title:SENSORS

  Language:English

  Document Type:Article

  Abstract:The spectrum confocal displacement sensor is an innovative type of photoelectric sensor. The non-contact advantages of this method include the capacity to obtain highly accurate measurements without inflicting any harm as well as the ability to determine the object's surface contour recovery by reconstructing the measurement data. Consequently, it has been widely used in the field of three-dimensional topographic measuring. The spectral confocal displacement sensor consists of a light source, a dispersive objective, and an imaging spectrometer. The scanning mode can be categorized into point scanning and line scanning. Point scanning is inherently present when the scanning efficiency is low, resulting in a slower measurement speed. Further improvements are necessary in the research on the line-scanning type. It is crucial to expand the measurement range of existing studies to overcome the limitations encountered during the detection process. The objective of this study is to overcome the constraints of the existing line-swept spectral confocal displacement sensor's limited measuring range and lack of theoretical foundation for the entire system. This is accomplished by suggesting an appropriate approach for creating the optical design of the dispersive objective lens in the line-swept spectral confocal displacement sensor. Additionally, prism-grating beam splitting is employed to simulate and analyze the imaging spectrometer's back end. The combination of a prism and a grating eliminates the spectral line bending that occurs in the imaging spectrometer. The results indicate that a complete optical pathway for the line-scanning spectral confocal displacement sensor has been built, achieving an axial resolution of 0.8 mu m, a scanning line length of 24 mm, and a dispersion range of 3.9 mm. This sensor significantly expands the range of measurements and fills a previously unaddressed gap in the field of analyzing the current stage of line-scanning spectral confocal displacement sensors. This is a groundbreaking achievement for both the sensor itself and the field it operates in. The line-scanning spectral confocal displacement sensor's design addresses a previously unmet need in systematic analysis by successfully obtaining a wide measuring range. This provides systematic theoretical backing for the advancement of the sensor, which has potential applications in the industrial detection of various ranges and complicated objects.

  Addresses:[Yang, Weiguang; Du, Jian; Qi, Meijie; Yan, Jiayue; Cheng, Mohan; Zhang, Zhoufeng] Chinese Acad Sci, Xian Inst Opt & Precis Mech, Key Lab Spectral Imaging Technol CAS, Xian 710119, Peoples R China; [Yang, Weiguang; Yan, Jiayue; Cheng, Mohan] Univ Chinese Acad Sci, Beijing 100049, Peoples R China

  Affiliations:Chinese Academy of Sciences; Xi'an Institute of Optics & Precision Mechanics, CAS; Chinese Academy of Sciences; University of Chinese Academy of Sciences, CAS

  Publication Year:2024

  Volume:24

  Issue:3

  Article Number:723

  DOI Link:http://dx.doi.org/10.3390/s24030723

  数据库ID（收录号）:WOS:001160046600001
• Record 321 of
  
  Title:Sub-Bin Delayed High-Range Accuracy Photon-Counting 3D Imaging
  
  Author Full Names:Yin, Hao-Meng; Zhao, Hui; Yang, Ming-Yang; Liu, Yong-An; Sheng, Li-Zhi; Fan, Xue-Wu

  Source Title:PHOTONICS

  Language:English

  Document Type:Article

  Keywords Plus:IMPROVEMENT; RESOLUTION

  Abstract:The range accuracy of single-photon-array three-dimensional (3D) imaging systems is limited by the time resolution of the array detectors. We introduce a method for achieving super-resolution in 3D imaging through sub-bin delayed scanning acquisition and fusion. Its central concept involves the generation of multiple sub-bin difference histograms through sub-bin shifting. Then, these coarse time-resolution histograms are fused with multiplied averages to produce finely time-resolved detailed histograms. Finally, the arrival times of the reflected photons with sub-bin resolution are extracted from the resulting fused high-time-resolution count distribution. Compared with the sub-delayed with the fusion method added, the proposed method performs better in reducing the broadening error caused by coarsened discrete sampling and background noise error. The effectiveness of the proposed method is examined at different target distances, pulse widths, and sub-bin scales. The simulation analytical results indicate that small-scale sub-bin delays contribute to superior reconstruction outcomes for the proposed method. Specifically, implementing a sub-bin temporal resolution delay of a factor of 0.1 for a 100 ps echo pulse width substantially reduces the system ranging error by three orders of magnitude. Furthermore, Monte Carlo simulations allow to describe a low signal-to-background noise ratio (0.05) characterised by sparsely reflected photons. The proposed method demonstrates a commendable capability to simultaneously achieve wide-ranging super-resolution and denoising. This is evidenced by the detailed depth distribution information and substantial reduction of 95.60% in the mean absolute error of the reconstruction results, confirming the effectiveness of the proposed method in noisy scenarios.

  Addresses:[Yin, Hao-Meng; Zhao, Hui; Yang, Ming-Yang; Fan, Xue-Wu] Chinese Acad Sci, Space Opt Technol Res Dept, Xi An Inst Opt & Precis Mech, Xian 710119, Peoples R China; [Yin, Hao-Meng; Zhao, Hui; Fan, Xue-Wu] Univ Chinese Acad Sci, Beijing 100049, Peoples R China; [Liu, Yong-An; Sheng, Li-Zhi] Chinese Acad Sci, Xian Inst Opt & Precis Mech, State Key Lab Transient Opt & Photon, Xian 710119, Peoples R China

  Affiliations:Chinese Academy of Sciences; Xi'an Institute of Optics & Precision Mechanics, CAS; Chinese Academy of Sciences; University of Chinese Academy of Sciences, CAS; Chinese Academy of Sciences; Xi'an Institute of Optics & Precision Mechanics, CAS; State Key Laboratory of Transient Optics & Photonics

  Publication Year:2024

  Volume:11

  Issue:2

  Article Number:181

  DOI Link:http://dx.doi.org/10.3390/photonics11020181

  数据库ID（收录号）:WOS:001172726700001
• Record 322 of
  
  Title:Consumer Camera Demosaicking and Denoising With a Collaborative Attention Fusion Network
  
  Author Full Names:Yuan, Nianzeng; Li, Junhuai; Sun, Bangyong

  Source Title:IEEE TRANSACTIONS ON CONSUMER ELECTRONICS

  Language:English

  Document Type:Article

  Keywords Plus:IMAGE; INTERPOLATION

  Abstract:For the consumer cameras with Bayer filter array, raw color filter array (CFA) data collected in real-world is sampled with signal-dependent noise. Various joint denoising and demosaicking (JDD) methods are utilized to reconstruct full-color and noise-free images. However, some artifacts (e.g., remaining noise, color distortion, and fuzzy details) still exist in the reconstructed images by most JDD models, mainly due to the highly related challenges of low sampling rate and signal-dependent noise. In this paper, a collaborative attention fusion network (CAF-Net), with two key modules, is proposed to solve this issue. Firstly, a multi-weight attention module is proposed to efficiently extract image features by realizing the interaction of spatial, channel, and pixel attention mechanisms. By designing a local feedforward network and mask convolution aggregation of multiple receptive fields, we then propose an effective dual-branch feature fusion module, which enhances image details and spatial correlation. Accordingly, the proposed two modules significantly facilitate our CAF-Net to recover a high-quality image, by accurately inferring the correlations of color, noise, and the spatial distribution of the CFA data. Extensive experiments on demosaicking, synthetic, and real image JDD tasks prove that the proposed CAF-Net can achieve advanced performance in terms of objective evaluation index metrics and visual perception.

  Addresses:[Yuan, Nianzeng; Li, Junhuai] Xian Univ Technol, Sch Comp Sci & Engn, Xian 710048, Peoples R China; [Li, Junhuai] Xian Univ Technol, Shaanxi Key Lab Network Comp & Secur Technol, Xian 710048, Peoples R China; [Sun, Bangyong] Xian Univ Technol, Sch Printing Packaging & Digital Media, Xian 710048, Peoples R China; [Sun, Bangyong] Chinese Acad Sci, Xian Inst Opt & Precis Mech, Key Lab Spectral Imaging Technol, Xian 7119, Peoples R China

  Affiliations:Xi'an University of Technology; Xi'an University of Technology; Xi'an University of Technology; Chinese Academy of Sciences; Xi'an Institute of Optics & Precision Mechanics, CAS

  Publication Year:2024

  Volume:70

  Issue:1

  Start Page:509

  End Page:521

  DOI Link:http://dx.doi.org/10.1109/TCE.2023.3342035

  数据库ID（收录号）:WOS:001244892900319
• Record 323 of
  
  Title:Duplex-Hierarchy Representation Learning for Remote Sensing Image Classification
  
  Author Full Names:Yuan, Xiaobin; Zhu, Jingping; Lei, Hao; Peng, Shengjun; Wang, Weidong; Li, Xiaobin

  Source Title:SENSORS

  Language:English

  Document Type:Article

  Keywords Plus:CONVOLUTIONAL NEURAL-NETWORKS; SCENE CLASSIFICATION; ATTENTION; FUSION; SHAPE

  Abstract:Remote sensing image classification (RSIC) is designed to assign specific semantic labels to aerial images, which is significant and fundamental in many applications. In recent years, substantial work has been conducted on RSIC with the help of deep learning models. Even though these models have greatly enhanced the performance of RSIC, the issues of diversity in the same class and similarity between different classes in remote sensing images remain huge challenges for RSIC. To solve these problems, a duplex-hierarchy representation learning (DHRL) method is proposed. The proposed DHRL method aims to explore duplex-hierarchy spaces, including a common space and a label space, to learn discriminative representations for RSIC. The proposed DHRL method consists of three main steps: First, paired images are fed to a pretrained ResNet network for extracting the corresponding features. Second, the extracted features are further explored and mapped into a common space for reducing the intra-class scatter and enlarging the inter-class separation. Third, the obtained representations are used to predict the categories of the input images, and the discrimination loss in the label space is minimized to further promote the learning of discriminative representations. Meanwhile, a confusion score is computed and added to the classification loss for guiding the discriminative representation learning via backpropagation. The comprehensive experimental results show that the proposed method is superior to the existing state-of-the-art methods on two challenging remote sensing image scene datasets, demonstrating that the proposed method is significantly effective.

  Addresses:[Yuan, Xiaobin; Zhu, Jingping] Xi An Jiao Tong Univ, Sch Elect & Informat Engn, Xian 710049, Peoples R China; [Yuan, Xiaobin] Chinese Acad Sci, Xian Inst Opt & Precis Mech, Xian 710119, Peoples R China; [Lei, Hao] Xi An Jiao Tong Univ, Natl Key Lab Human Machine Hybrid Augmented Intell, Xian 710049, Peoples R China; [Lei, Hao] Xi An Jiao Tong Univ, Inst Artificial Intelligence & Robot, Xian 710049, Peoples R China; [Peng, Shengjun] China Xian Satellite Control Ctr, State Key Lab Astronaut Dynam, Xian 710043, Peoples R China; [Wang, Weidong] PLA 63768, Xian 710600, Peoples R China; [Li, Xiaobin] Beijing Inst Remote Sensing Informat, Beijing 100192, Peoples R China

  Affiliations:Xi'an Jiaotong University; Chinese Academy of Sciences; Xi'an Institute of Optics & Precision Mechanics, CAS; Xi'an Jiaotong University; Xi'an Jiaotong University

  Publication Year:2024

  Volume:24

  Issue:4

  Article Number:1130

  DOI Link:http://dx.doi.org/10.3390/s24041130

  数据库ID（收录号）:WOS:001172469400001
• Record 324 of
  
  Title:Study on the construction of twisted cosine partially coherent beams and their propagation characteristics
  
  Author Full Names:Zhang, Shaohua; Zhou, Yuan; Chai, Yutong; Qu, Jun

  Source Title:AIP ADVANCES

  Language:English

  Document Type:Article

  Keywords Plus:SCHELL-MODEL BEAMS; EXPERIMENTAL GENERATION; FREE-SPACE; ARRAY

  Abstract:We propose a novel Schell model source for generating twisted partially coherent beams with an initial radius of curvature, which is called a twisted flat-topped cosine Gaussian Schell-model (TFCGSM) source. The TFCGSM beam comprises a wavefront phase and a flat-top structure, with the source degree of coherence determined by two cosine functions. Based on the Huygens-Fresnel principle, the general analytical expression of the cross-spectral density function of the TFCGSM beam propagating through the paraxial ABCD optical system is derived, and then its propagation properties are studied. The results show that the conversion of the array of the beam and the non-uniform structure can be realized by adjusting the parameters in the source plane. As the propagation distance of the TFCGSM beam increases, it rotates around the axis and increases the intensity of the array distribution. Surprisingly, the initial radius of curvature can cause the beam to rotate. The unique shape and properties of the TFCGSM beam create new possibilities for optical communication and enhanced optical functions. (c) 2024 Author(s). All article content, except where otherwise noted, is licensed under a Creative Commons Attribution (CC BY) license(http://creativecommons.org/licenses/by/4.0/).

  Addresses:[Zhang, Shaohua; Chai, Yutong; Qu, Jun] Anhui Normal Univ, Anhui Prov Key Lab Control & Applicat Optoelect In, Wuhu 241000, Anhui, Peoples R China; [Zhou, Yuan] Chinese Acad Sci, Xian Inst Opt & Precis Mech, State Key Lab Transient Opt & Photon, Xian 710119, Shaanxi, Peoples R China; [Zhou, Yuan] Univ Chinese Acad Sci, Beijing 100049, Peoples R China

  Affiliations:Anhui Normal University; State Key Laboratory of Transient Optics & Photonics; Chinese Academy of Sciences; Xi'an Institute of Optics & Precision Mechanics, CAS; Chinese Academy of Sciences; University of Chinese Academy of Sciences, CAS

  Publication Year:2024

  Volume:14

  Issue:2

  Article Number:25235

  DOI Link:http://dx.doi.org/10.1063/5.0186514

  数据库ID（收录号）:WOS:001163573400004