2024
2024
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Record 505 of
Title:Depth-resolved imaging through dynamic scattering media via speckle cross-correlation under near-infrared illumination
Author Full Names:Wang, Ping(1,2); Zhou, Meiling(2); Zhang, Yang(2,3); Li, Runze(2); Peng, Tong(2); Zhou, Yuan(2,3); Min, Junwei(2); Yao, Cuiping(1); Yao, Baoli(2,3)Source Title:Journal of Physics D: Applied PhysicsLanguage:EnglishDocument Type:Journal article (JA)Abstract:Speckle cross-correlation imaging (SCCI) method has the depth-resolved capability, benefiting from the introduction of a reference point. However, the quality of the reconstructed image is degraded due to the background noise, which becomes more prominent when imaging through dynamic scattering media. Here, we propose a composite-differential filter-assisted (CDF-SCCI) method, allowing for effectively reducing the background noise of the reconstructed image. The signal-to-background ratios of the reconstructed images by employing the CDF-SCCI method can be enhanced by a maximum of 4.15 dB (corresponding to 2.6 times) compared to the SCCI method. Furthermore, we apply the near-infrared (NIR) illumination to the imaging system of dynamic scattering media and prove that the NIR illumination not only enhances the penetration depth of imaging, but also improves the quality of reconstructed images compared to the visible illumination. The depth-resolved imaging through various dynamic biological scattering media, including the milk and anticoagulated pig blood, further demonstrates the potential application of the proposed CDF-SCCI method in biomedical imaging. ? 2024 IOP Publishing Ltd.Affiliations:(1) Key Laboratory of Biomedical Information Engineering of Ministry of Education, Institute of Biomedical Photonics and Sensing, School of Life Science and Technology, Xi’an Jiaotong University, Shaanxi, Xi’an; 710049, China; (2) Xi’an Institute of Optics and Precision Mechanics, Chinese Academy of Sciences, Xi’an; 710119, China; (3) University of Chinese Academy of Sciences, Beijing; 100049, ChinaPublication Year:2024Volume:57Issue:39Article Number:395401DOI Link:10.1088/1361-6463/ad5c70數(shù)據(jù)庫(kù)ID（收錄號(hào)）:20242816696258 -
Record 506 of
Title:Sprnet:Laser Spot Center Position and Reconstruction Under Atmospheric Turbulence Based on Deep Learning Enhancement
Author Full Names:Wang, Jiaqi(1,2); Meng, Xiangsheng(1); Zhou, Shun(2); Wang, Xuan(1); Han, Junfeng(1); Guo, Yifan(1,2); Song, Shigeng(3); Liu, Weiguo(2)Source Title:SSRNLanguage:EnglishDocument Type:Preprint (PP)Abstract:Optical communication suffers from atmospheric turbulence for free space optical communication (FSOC) and the received spot has undergone severe wavefront distortion. It is difficult to position the spot center accurately or reconstruct the original spot, which leads to the loss of the transmitted information. Therefore, we establish a novel neural network to achieve spot center position and reconstruction, named SPRNet. Our SPRNet consists of spot structural feature extraction (SSFE) module and field distribution feature enhancement (FDFE) module to locate the center and restore the quality-enhanced spot. In FDFE module, we propose a novel spot-constrained attention module to better fuse the dual feature. To solve the problem of lacking ground truth (label), we propose the multi-frame aggregation method to obtain the labels to train our deep-learning-based method and establish the Turbulence50 dataset. We carried out experiments with simulated data and real-world data to verify the effectiveness of our SPRNet. The experiment results show that our method has better performance and strong robustness compared to other methods, which improves more than 2.24 pixels on the benchmark of Manhattan distance for spot center position and more than 3.39dB on the benchmark of PSNR for spot reconstruction. ? 2024, The Authors. All rights reserved.Affiliations:(1) Key Laboratory of Space Precision Measurement Technology, Xi’an Institute of Optics and Precision Mechanics, Chinese Academy of Sciences, Xi’an; 710119, China; (2) School of Opto-electronical Engineering, Xi’an Technological University, Xi’an; 710021, China; (3) Institute of Thin Films, Sensors and Imaging, Scottish Universities Physics Alliance (SUPA), University of the West of Scotland, Paisley; PA1 2BE, United KingdomPublication Year:2024DOI Link:10.2139/ssrn.4937077數(shù)據(jù)庫(kù)ID（收錄號(hào)）:20240356176 -
Record 507 of
Title:Archimedes spiral optical vortex array emitter
Author Full Names:Xin, M.A.(1); Wang, Ruoyu(1); Zhang, Hao(1); Tang, Miaomiao(1); Yuping, T.A.I.(1,2); Xinzhong, L.I.(1,2,3)Source Title:Optics ExpressLanguage:EnglishDocument Type:Journal article (JA)Abstract:Optical vortex arrays (OVAs) are important for large-capacity optical communications, optical tweezers, and optical imaging. However, there is an urgent need to generate an optical vortex emitter to construct a specific OVA with a functional structure for the accurate transport of particles. To address this issue, we propose an Archimedes spiral OVA emitter that uses an Archimedes spiral parametric equation and coordinate localization techniques to dynamically regulate the position of each optical vortex. We discuss the phenomena of the location coordinates and Archimedes spiral from unclosed to closed on the OVA emitter. Furthermore, the propose of multiple OVA emitters demonstrates a chiral structure that has the potential for optical material processing. This study lays the foundation for generating OVAs with functional structures, which will facilitate advanced applications in the complex manipulation, separation, and transport of multiple particles. ? 2024 Optica Publishing Group under the terms of the Optica Open Access Publishing Agreement.Affiliations:(1) School of Physics and Engineering, Henan University of Science and Technology, Luoyang; 471023, China; (2) State Key Laboratory of Transient Optics and Photonics, Xi’an Institute of Optics and Precision Mechanics, Chinese Academy of Sciences, Xi’an; 710119, China; (3) Provincial and Ministerial Co-Construction of Collaborative Innovation Center for Non-Ferrous Metal New Materials and Advanced Processing Technology, Luoyang; 471023, ChinaPublication Year:2024Volume:32Issue:13Start Page:23115-23124DOI Link:10.1364/OE.523806數(shù)據(jù)庫(kù)ID（收錄號(hào)）:20242616421937 -
Record 508 of
Title:Kerr Optical Frequency Comb Evolution in a Gain Fiber Cavity Embedded with a Microresonator
Author Full Names:Liu, Ziyu(1,3); Wang, Gang(1,3); Tian, Jinshou(1); Lou, Rui(2); Shen, Jun(2); Wang, Weiqiang(2); Zhao, Wei(2)Source Title:SSRNLanguage:EnglishDocument Type:Preprint (PP)Abstract:Microcavity-based frequency combs, or ‘microcombs’ have enabled many fundamental breakthroughs of cavity optical physics during the last decade, which also show excellent values in many application fields. In this paper, we experimentally demonstrate Kerr optical frequency comb evolution in a gain fiber cavity embedded with a high-Q micro-ring resonator. Through tuning the pump power and polarization state, single frequency laser, mode-locked laser (primary-comb-like), bunched sub-combs, phase-locked comb and high-noise combs are observed in sequence. The proposed scheme is low power consumption as the optical frequency combs are formed by stimulated emission in a gain cavity and phase locked by thresholdless four wave mixing effect in a micro-resonator. The proposed optical frequency comb exhibits excellent thermal stability for the intrinsic feedback mechanism. Further, our scheme has the potential to realize full integration by replacing the fiber devices with semiconductor components. ? 2024, The Authors. All rights reserved.Affiliations:(1) Key Laboratory of Ultra-fast Photoelectric Diagnostics Technology, Xi’an Institute of Optics and Precision Mechanics (XIOPM), Chinese Academy of Sciences (CAS), Shaanxi, Xi’an; 710119, China; (2) State Key Laboratory of Transient Optics and Photonics, Xi’an Institute of Optics and Precision Mechanics (XIOPM), Chinese Academy of Sciences (CAS), Shaanxi, Xi’an; 710119, China; (3) University of Chinese Academy of Sciences, Beijing; 100049, ChinaPublication Year:2024DOI Link:10.2139/ssrn.4765422數(shù)據(jù)庫(kù)ID（收錄號(hào)）:20240116387 -
Record 509 of
Title:Wearable Human-Machine Gesture Interaction Based on Fabric Piezoelectric Sensor
Author Full Names:Lu, Yiming(1); Li, Zewen(1); Wang, Xinwang(1); Jiang, Jiashun(1); Zhu, Mingzhu(2); Xie, Mengying(1)Source Title:IEEE Sensors JournalLanguage:EnglishDocument Type:Journal article (JA)Abstract:Gesture recognition has great application prospects in the field of human-machine interaction (HMI). To date, the development of wearable and cost-effective sensors for gesture recognition remains a challenge. In this study, we propose a comprehensive system solution for gesture recognition and HMI-based on electrospun polyvinylidene fluoride (PVDF)/barium titanate (BaTiO3) nanocomposite membrane sensors. The sensor comprising three types of fabric can effectively recognize different bending angles and exhibits reliable repeatability. The gesture classification recognition based on the sensor exhibits high accuracy in three machine learning algorithms [K nearest neighbor (KNN), support vector machine (SVM), and neural network (NN)], with accuracy rates of 96.7%, 97.9%, and 97.8% achieved over 5000 groups of ten different gestures. Additionally, we design a scheme for real-time remote control of a mechanical claw based on this sensor. The results demonstrate that the proposed solution provides a promising platform for gesture recognition and HMI. 1558-1748. ? 2024 IEEE.Affiliations:(1) Tianjin University, State Key Laboratory of Precision Measuring Technology and Instrument, School of Precision Instrument and Opto-Electronics Engineering, Tianjin; 300072, China; (2) Northwestern Polytechnical University, School of Astronautics, Xi'an; 710072, ChinaPublication Year:2024Volume:24Issue:15Start Page:25141-25149DOI Link:10.1109/JSEN.2024.3416188數(shù)據(jù)庫(kù)ID（收錄號(hào)）:20242816661076 -
Record 510 of
Title:High accuracy ranging for space debris with spaceborne single photon Lidar
Author Full Names:Tian, Yuan(1,2,3,4); Hu, Xiaodong(2); Chen, Songmao(1,2,4); Zhao, Yixin(1,2,3,4); Zhang, Xuan(1,2,3,4); Wang, Dingjie(1,2,3,4); Xu, Weihao(1,2,3,4); Xie, Meilin(1,2,4); Hao, Wei(1,2,4); Su, Xiuqin(1,2,4)Source Title:Optics ExpressLanguage:EnglishDocument Type:Journal article (JA)Abstract:The increasing risk posed by space debris highlights the need for accurate localization techniques. Spaceborne single photon Lidar (SSPL) offers a promising solution, overcoming the limitations of traditional ground-based systems by providing expansive coverage and superior maneuverability without being hindered by weather, time, or geographic constraints. This study introduces a novel approach leveraging non-parametric Bayesian inference and the Dirichlet process mixture model (DPMM) to accurately determine the distance of space debris in low Earth orbit (LEO), where debris exhibits nonlinear, high dynamic motion characteristics. By integrating extended Kalman filtering (EKF) for range gating, our method captures the temporal distribution of reflected photons, employing Markov chain Monte Carlo (MCMC) for iterative solutions. Experimental outcomes demonstrate our method s superior accuracy over conventional statistical techniques, establishing a clear correlation between radial absolute velocity and ranging error, thus significantly enhancing monostatic space debris localization. ? 2024 Optica Publishing Group (formerly OSA). All rights reserved.Affiliations:(1) Key Laboratory of Space Precision Measurement Technology, Xi an Institute of Optics and Precision Mechanics, Chinese Academy of Sciences, Xi an; 710119, China; (2) Xi an Institute of Optics and Precision Mechanics, Chinese Academy of Sciences, Xi an; 710119, China; (3) University of Chinese Academy of Sciences, Beijing; 100049, China; (4) Pilot National Laboratory for Marine Science and Technology, Qingdao; 266200, ChinaPublication Year:2024Volume:32Issue:7Start Page:12318-12339DOI Link:10.1364/OE.519002數(shù)據(jù)庫(kù)ID（收錄號(hào)）:20241415837511 -
Record 511 of
Title:Two-dimensional numerical simulation of pre-ionized direct-current glow discharge in atmospheric helium*
Author Full Names:Liu, Zai-Hao(1,2); Liu, Ying-Hua(1,2); Xu, Bo-Ping(1,2); Yin, Pei-Qi(1,2); Li, Jing(3); Wang, Yi-Shan(1,2); Zhao, Wei(1,2); Duan, Yi-Xiang(4); Tang, Jie(1,2)Source Title:Wuli Xuebao/Acta Physica SinicaLanguage:ChineseDocument Type:Journal article (JA)Abstract:In this paper, the effect of pre-ionization on the small-gap and large-gap direct-current glow discharge at atmospheric pressure are investigated based on a two-dimensional self-consistent fluid model. For both the discharges, the results show that with the enhancement of pre-ionization, the charged particle distribution gradually shifts toward the cathode along the discharge direction, making the cathode fall zone shrink continuously. The width of the positive column region, negative glow space, and cathode fall zone continuously extend along the vertical discharge direction, and the distribution of electron density and ion density are more uniform. For the electric field, with the enhancement of pre-ionization, the longitudinalal component distribution of the electric field in the cathode fall zone gradually contracts toward the cathode, and the overall electric field near the cathode decreases and becomes more uniformly distributed. The transverse component distribution of the electric field gradually decreases and shrinks toward the wall. The overall electron temperature in the discharge space decreases with the enhancement of the pre-ionization level, and the electron temperature distribution in the cathode fall zone gradually shrinks toward the cathode. In addition, the overall potential of the discharge space also decreases. The introduction of pre-ionization significantly reduces the maintaining voltage and discharge power of the direct-current glow discharge. Furthermore, the potential drop in the small-gap discharge is always concentrated in the cathode fall zone as the pre-ionization increases, while the potential drop in the large-gap discharge is gradually shifted from the cathode fall zone to the positive column region. This simulation shows that the pre-ionization not only effectively enhances the discharge uniformity, but also largely reduces the maintaining voltage and energy consumption of the direct-current glow discharge. This work is an important guideline for further optimizing the electrode configuration and the operating parameters of the plasma source. ? 2024 Institute of Physics, Chinese Academy of Sciences. All rights reserved.Affiliations:(1) State Key Laboratory of Transient Optics and Photonics, Xi’an Institute of Optics and Precision Mechanics, Chinese Academy of Sciences, Xi’an; 710119, China; (2) University of Chinese Academy of Sciences, Beijing; 100049, China; (3) Faculty of Mathematics and Physics, Huaiyin Institute of Technology, Huaian; 223003, China; (4) Research Center of Analytical Instrumentation, School of Mechanical Engineering, Sichuan University, Chengdu; 610064, ChinaPublication Year:2024Volume:73Issue:1Article Number:015101DOI Link:10.7498/aps.73.20230712數(shù)據(jù)庫(kù)ID（收錄號(hào)）:20240815605290 -
Record 512 of
Title:Remote Sensing LiDAR and Hyperspectral Classification with Multi-Scale Graph Encoder–Decoder Network
Author Full Names:Wang, Fang(1); Du, Xingqian(2); Zhang, Weiguang(1); Nie, Liang(1); Wang, Hu(1,3,4,5); Zhou, Shun(1); Ma, Jun(6)Source Title:Remote SensingLanguage:EnglishDocument Type:Journal article (JA)Abstract:The rapid development of sensor technology has made multi-modal remote sensing data valuable for land cover classification due to its diverse and complementary information. Many feature extraction methods for multi-modal data, combining light detection and ranging (LiDAR) and hyperspectral imaging (HSI), have recognized the importance of incorporating multiple spatial scales. However, effectively capturing both long-range global correlations and short-range local features simultaneously on different scales remains a challenge, particularly in large-scale, complex ground scenes. To address this limitation, we propose a multi-scale graph encoder–decoder network (MGEN) for multi-modal data classification. The MGEN adopts a graph model that maintains global sample correlations to fuse multi-scale features, enabling simultaneous extraction of local and global information. The graph encoder maps multi-modal data from different scales to the graph space and completes feature extraction in the graph space. The graph decoder maps the features of multiple scales back to the original data space and completes multi-scale feature fusion and classification. Experimental results on three HSI-LiDAR datasets demonstrate that the proposed MGEN achieves considerable classification accuracies and outperforms state-of-the-art methods. ? 2024 by the authors.Affiliations:(1) School of Optoelectronic Engineering, Xi’an Technological University, Xi’an; 710021, China; (2) China Academy of Space Technology (Xi’an), Xi’an; 710100, China; (3) Xi’an Institute of Optics and Precision Mechanics of CAS, Xi’an; 710119, China; (4) University of Chinese Academy of Sciences, Beijing; 100049, China; (5) Xi’an Space Sensor Optical Technology Engineering Research Center, Xi’an; 710119, China; (6) Institute for Interdisciplinary and Innovation Research, Xi’an Technological University, Xi’an; 710021, ChinaPublication Year:2024Volume:16Issue:20Article Number:3912DOI Link:10.3390/rs16203912數(shù)據(jù)庫(kù)ID（收錄號(hào)）:20244417294092 -
Record 513 of
Title:Topological edge states in photonic Floquet insulator with unpaired Dirac cones
Author Full Names:Zhong, Hua(1); Kartashov, Yaroslav V.(2); Li, Yongdong(1); Li, Ming(3); Zhang, Yiqi(1)Source Title:arXivLanguage:EnglishDocument Type:Preprint (PP)Abstract:Topological insulators are most frequently constructed using lattices with specific degeneracies in their linear spectra, such as Dirac points. For a broad class of lattices, such as honeycomb ones, these points and associated Dirac cones generally appear in non-equivalent pairs. Simultaneous breakup of the time-reversal and inversion symmetry in systems based on such lattices may result in the formation of the unpaired Dirac cones in bulk spectrum, but the existence of topologically protected edge states in such structures remains an open problem. Here photonic Floquet insulator on honeycomb lattice with unpaired Dirac cones in its spectrum is introduced that can support unidirectional edge states appearing at the edge between two regions with opposite sublattice detuning. Topological properties of this system are characterized by the nonzero valley Chern number. Remarkably, edge states in this system can circumvent sharp corners without inter-valley scattering even though there is no total forbidden gap in the spectrum. Our results reveal unusual interplay between two different physical mechanisms of creation of topological edge states based on simultaneous breakup of different symmetries of the system. ? 2024, CC0.Affiliations:(1) Key Laboratory for Physical Electronics and Devices, Ministry of Education, School of Electronic Science and Engineering, Xi’an Jiaotong University, Xi’an; 710049, China; (2) Institute of Spectroscopy, Russian Academy of Sciences, Troitsk, Moscow; 108840, Russia; (3) State Key Laboratory of Transient Optics and Photonics, Xi’an Institute of Optics and Precision Mechanics of Chinese Academy of Sciences, Xi’an; 710119, ChinaPublication Year:2024DOI Link:10.48550/arXiv.2407.05086數(shù)據(jù)庫(kù)ID（收錄號(hào)）:20240303088 -
Record 514 of
Title:Spectroscopic Mueller Metrix Polarimetry Based on Spectral Modulation and Division of Amplitude Demodulation
Author Full Names:Deng, Zhongxun(1,2); Quan, Naicheng(2); Li, Siyuan(3); Zhang, Chunmin(4)Source Title:Guangzi Xuebao/Acta Photonica SinicaLanguage:ChineseDocument Type:Journal article (JA)Abstract:Thin film and nanostructure measurement technologies have played an important role in production process monitoring in industries such as integrated circuit manufacturing, flat panel displays, and solar cells. Many optical based measurement techniques have emerged to meet the industrial needs of high-speed and nondestructive measurement. Spectroscopic Mueller Metrix Polarimetry(SMMP)is a typical representative of these techniques and has become an important direction in the research and development of thin film and nanostructure measurement technology. It uses a Polarization State Generator(PSG)to convert a certain spectral range of polychromatic light into fully polarized light and project it onto the surface of the sample to be tested, and uses the Polarization State Analyzer(PSA)to detect the polarization state of the reflected or transmitted light on the surface of the sample for obtaining all 16 Mueller matrix elements of the sample as a function of wavelength, and then analyzes and extracts their characteristic parameters such as complex dielectric constant, carrier structure, and film thickness. SMMP can be divided into frequency modulation type and time modulation type according to its working principle. The polarization state generator and polarization state analyzer of the former are both composed of components that can change modulation parameters over time and fixed linear polarizers, such as rotary compensators, liquid crystal phase delay devices, and photoblastic modulators. When measuring in a wide spectral range, the SMMP with dual rotation compensators is the most common:the compensators of PSG and PSA rotate at a certain rate to produce different time modulation frequencies, and then use Fourier transform demodulation to obtain all 16 Mueller matrix elements of the sample, which takes a long measurement time and is not suitable for situations where Mueller matrix elements change rapidly over time;The PSG and PSA of the latter are both composed of two high-order phase delay devices configured with a certain thickness and fixed fast axis direction, as well as a fixed linear polarizer. All 16 elements of the measured Mueller matrix are modulated to 37 different frequency channels, and the spectra of all 16 Mueller matrix elements can be obtained by channel filtering and Fourier transform. As the system does not contain moving components, static real-time measurement can be achieved. However, when the light source or the measured Mueller matrix has sharp characteristic peaks, serious channel crosstalk will occur, which affects measurement accuracy and accuracy. According to the principle of Fourier transform spectroscopy, a large channel bandwidth corresponds to high restoration spectral resolution. Due to the limited total channel bandwidth, an increase in the number of channels will reduce the bandwidth required to restore the Muller matrix spectrum. Therefore, the spectral resolution of the measured Mueller matrix elements is much smaller than the spectral resolution of the spectrometer. Therefore, it is only suitable for situations where the measured Mueller matrix slowly changes with wavelength. To overcome these limitations, we presented a SMMP based on frequency modulation and division of amplitude demodulation. Compared with the spectroscopic Mueller polarimetry based on time modulation or frequency-temporal modulation, it has no moving components and electronic devices, and can achieve real-time measurement of the spectra of all 16 Mueller matrix elements of the sample. Compared with the spectroscopic Mueller polarimetry based on frequency modulation, it has higher spectral resolution and lower the probability of channel crosstalk generation. According to the research results, the selection of high-order retarders and spectrometers can further expand the spectral range of measurement. By optimizing the calibration method, the accuracy and precision of optical measurement can be further improved. This article has certain scientific significance and potential application prospects in the research and development of high-speed, high-precision, and wide spectral band generalized spectral ellipsometry technology in the field of non-destructive testing technology. ? 2024 Chinese Optical Society. All rights reserved.Affiliations:(1) Shenmu Vocational and Technical College, Shenmu; 719300, China; (2) School of Materials Science and Engineering, Xi′an University of Technology, Xi′an; 710048, China; (3) Key Laboratory of Spectral Imaging Technology CAS, Xi′an Institute of Optics and Precision Mechanics, Chinese Academy of Sciences, Xi′an; 710119, China; (4) School of Science, Xi′an Jiaotong University, Xi′an; 710049, ChinaPublication Year:2024Volume:53Issue:4Article Number:0430004DOI Link:10.3788/gzxb20245304.0430004數(shù)據(jù)庫(kù)ID（收錄號(hào)）:20241715962743 -
Record 515 of
Title:Generalized theoretical model for the imaging-based atmospheric lidar technique
Author Full Names:Kong, Zheng(1,2); Yang, Xinglong(1); Cheng, Yuan(1); Gong, Zhenfeng(1); Liu, Dong(3); Zhao, Chunsheng(4); Hua, Dengxin(5); Mei, Liang(1)Source Title:Optics and Laser TechnologyLanguage:EnglishDocument Type:Journal article (JA)Abstract:In recent years, imaging-based lidar techniques have been widely studied and employed in atmospheric remote sensing, while different theoretical descriptions are introduced for lidar systems with specific optical configurations and a universal guideline for optimizing system performance is still lacking. In this work, a generalized theoretical model (GTM), suitable for various imaging-based atmospheric lidar techniques, has been concepted and established for describing the relationship between the system performances and optical configurations, where a few factors have been derived and defined. Comprehensive simulation studies based on the GTM have demonstrated that the range resolution, the blind range, the minimum scattering angle of the lidar signal and the tilt angle of the image sensor are strongly dependent on the focal length of the receiving lens (or telescope) and the transmitter–receiver separation, etc. In particular, the range resolution is proportional to the product between the focal length and the separation. Besides, the intensity factor, the signal-to-background ratio (SBR) factor, as well as the signal-to-noise ratio (SNR) factor, which are immune from atmospheric conditions, etc., have been proposed and deduced to quantify the performances of imaging-based lidar system with different optical configurations. It has been found out that the SBR factor, an indicator for the requirement on the dynamic range of the image sensor, is inversely proportional to the separation. Meanwhile, the intensity factor and the SNR factor are related to the separation, the focal length as well as the aperture of the receiving lens, etc. The GTM provides valuable insight for understanding the principle of the imaging-based atmospheric lidar technique as well as a general guideline for system design and implementation. ? 2024 Elsevier LtdAffiliations:(1) School of Optoelectronic Engineering and Instrumentation Science, Dalian University of Technology, Dalian; 116024, China; (2) School of Physics, Dalian University of Technology, Dalian; 116024, China; (3) Key Laboratory of Atmospheric Optics, Anhui Institute of Optics and Fine Mechanics, Hefei Institutes of Physical Science, Chinese Academy of Sciences, DC, Hefei; 230031, China; (4) Department of Atmospheric and Oceanic Sciences, School of Physics, Peking University, Beijing, China; (5) School of Mechanical and Precision Instrument Engineering, Xi'an University of Technology, Xi'an; 710048, ChinaPublication Year:2024Volume:178Article Number:111207DOI Link:10.1016/j.optlastec.2024.111207數(shù)據(jù)庫(kù)ID（收錄號(hào)）:20242316196970 -
Record 516 of
Title:Topological edge states in a photonic Floquet insulator with unpaired Dirac cones
Author Full Names:Zhong, Hua(1); Kartashov, Yaroslav V.(2); Li, Yongdong(1); Li, Ming(3); Zhang, Yiqi(1)Source Title:Photonics ResearchLanguage:EnglishDocument Type:Journal article (JA)Abstract:Topological insulators are most frequently constructed using lattices with specific degeneracies in their linear spectra, such as Dirac points. For a broad class of lattices, such as honeycomb ones, these points and associated Dirac cones generally appear in non-equivalent pairs. Simultaneous breakup of the time-reversal and inversion symmetry in systems based on such lattices may result in the formation of the unpaired Dirac cones in bulk spectrum, but the existence of topologically protected edge states in such structures remains an open problem. Here a photonic Floquet insulator on a honeycomb lattice with unpaired Dirac cones in its spectrum is introduced that can support unidirectional edge states appearing at the edge between two regions with opposite sublattice detuning. Topological properties of this system are characterized by the nonzero valley Chern number. Remarkably, edge states in this system can circumvent sharp corners without inter-valley scattering even though there is no total forbidden gap in the spectrum. Our results reveal unusual interplay between two different physical mechanisms of creation of topological edge states based on simultaneous breakup of different symmetries of the system. ? 2024 Chinese Laser Press.Affiliations:(1) Key Laboratory for Physical Electronics and Devices, Ministry of Education, School of Electronic Science and Engineering, Xi’an Jiaotong University, Xi’an; 710049, China; (2) Institute of Spectroscopy, Russian Academy of Sciences, Moscow; 108840, Russia; (3) State Key Laboratory of Transient Optics and Photonics, Xi’an Institute of Optics and Precision Mechanics, Chinese Academy of Sciences, Xi’an; 710119, ChinaPublication Year:2024Volume:12Issue:10Start Page:2078-2087DOI Link:10.1364/PRJ.524824數(shù)據(jù)庫(kù)ID（收錄號(hào)）:20244217196367