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Record 349 of
Title:Research progress and core technologies of optical-mechanical system based on additive manufacturing
Author(s):Jia, Xinyin(1,2); Hu, Bingliang(1); Wang, Feicheng(1); Li, Siyuan(1); Sun, Lijun(1); Wu, Junqiang(1)
Source: Proceedings of SPIE - The International Society for Optical Engineering Volume: 12060 Issue: DOI: 10.1117/12.2606752 Published: 2021
Abstract:The research on optical-mechanical system based on additive manufacturing is based on additive manufacturing, diamond turning, high-precision magnetorheological polishing, surface modification technology, internal lattice structure topology optimization and so on. It can overcome the problems of adhesive use and material matching in the traditional structure design, greatly reduce the difficulty of assembly and thermal control, and realize the lightweight design of internal structure that can not be realized by traditional processing methods. In addition, because the mirror body and its supporting structure are made of same metal materials and integrated, the strength and stiffness are greatly improved compared with the traditional design method. This paper summarizes the development status and technical parameters of additive manufacturing opto-mechanical system at home and abroad. The research progress of surface modification technology by domestic and foreign scholars was focused and the post-processing process and core technologies of the optical-mechanical system were described. ? 2021 SPIE.
Accession Number: 20220211446977
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Record 350 of
Title:Stray light test facility for multispectral spaced-based optical system with large field of view
Author(s):Zhao, Qice(1); Xu, Xiping(1); Qiao, Yang(1); Pan, Yue(1); Lu, Yi(1); Xu, Liang(2); Liu, Feng(2)
Source: Proceedings of SPIE - The International Society for Optical Engineering Volume: 11763 Issue: DOI: 10.1117/12.2588249 Published: 2021
Abstract:In order to evaluate the ability of a space-based optical system to suppress off-axis stray light, a large-field, multispectrum space-based stray light test method based on point source transmittance (PST) is proposed in this paper. A stray light test facility is constructed using multiple laser sources, large aperture off-axis reflective parallel light tubes and a high-precision positioning mechanism to evaluate the PST index of stray light in the visible and near infrared bands for a space-based optical system. Based on theoretical analysis, experimental measurements of standard lenses in various wavelength bands have proven that the dynamic range of the facility in the visible light band is 10-6 and in the infrared band is 10-3. The facility has the advantages of wide range of detectable wavelengths, high automation, and large dynamic range. The test results can be used for correction of the hood, which provides a reliable traceability basis for the stray light suppression of a space-based optical system. ? 2021 SPIE
Accession Number: 20211410162263
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Record 351 of
Title:Techniques for On-orbit Calibration of Space Optical Imaging Systems Based on Auto-collimation
Author(s):Zhao, Hengxiang(1,2); Li, Libo(1); Feng, Yutao(1); Li, Yong(1); Liu, Wei(3); Wu, Junqiang(1); Yan, Peng(1); Bai, Qinglan(1)
Source: Guangzi Xuebao/Acta Photonica Sinica Volume: 50 Issue: 1 DOI: 10.3788/gzxb20215001.0112003 Published: January 25, 2021
Abstract:Through the analysis of imaging principle, simulation of optical model and construction of the principle prototype, the main factors affecting the calibration accuracy of the autocollimation calibration system in the experimental environment are discussed, and the main issues of the calibration system are put forward, which should be noticed in the design and work, including pixel size selection, image point location algorithm, focus amount calculation and system installation error. According to the analysis results, the calibration error of the principle prototype is corrected. Finally, the calibration accuracy of the principle prototype is less than 0.4 mm, and the calibration accuracy of the rotation in X, Y and Z directions are less than 0.6", 0.6" and 12" respectively. The relative error of accuracy is better than 0.2%. ? 2021, Science Press. All right reserved.
Accession Number: 20210809975869
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Record 352 of
Title:Hyperspectral Abnormal Target Detection Based on Extended Multi-attribute Profile and Fast Local RX Algorithm
Author(s):A, Ruhan(1); Yuan, Xiaobin(2); Mu, Xiaodong(1); Wang, Jingyi(3)
Source: Guangzi Xuebao/Acta Photonica Sinica Volume: 50 Issue: 9 DOI: 10.3788/gzxb20215009.0910002 Published: September 25, 2021
Abstract:In order to further improve the speed and accuracy of hyperspectral abnormal target detection, a fast anomaly target detection method based on extended multi-attribute profiles and improved Reed-Xiaoli is proposed. Extended multi-attribute Profiles are extracted from the original hyperspectral images by mathematical morphological transformations. Moreover, a novel fast local Reed-Xiao algorithm is also proposed. Iteratively update inverse matrix of covariance using matrix inverse lemma, thereby reducing the computational complexity of the Mahalanobis distance. The combination of extended multi-attribute profiles and fast local Reed-Xiaoli detector effectively utilizes the spectral information and spatial information of hyperspectral images, it greatly improves the detection accuracy and reduce the running time. Experimental results on three real data sets show the AUC value of the algorithm in this paper is 0.996 7, 0.985 6 and 0.981 6 respectively. The operation time is 21.218 1 s, 15.192 8 s and 32.337 9 s respectively. The proposed method has obvious advantages in detection accuracy and speed, and has good practical value. ? 2021, Science Press. All right reserved.
Accession Number: 20213910941992
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Record 353 of
Title:Diode-pumped SESAM mode-locked low-repetition-rate Tm:CALGO picosecond laser at 1968 nm
Author(s):Guo, Lei(1,2,3); Yang, Yaling(1,2,3); Zhao, Shengzhi(3); Li, Tao(3); Qiao, Wenchao(3,4); Wang, Ruihua(2); Zhang, Baitao(2,6); Yang, Kejian(2,4,5,6); He, Jingliang(2,6); Li, Xun(7)
Source: Optics and Laser Technology Volume: 142 Issue: DOI: 10.1016/j.optlastec.2021.107195 Published: October 2021
Abstract:A diode-pumped SESAM continuous-wave mode-locked (CWML) Tm:CALGO laser is demonstrated at a new center wavelength of 1968 nm based on a ultra-long Z-shaped folding cavity configuration. A total maximum dual-output power of 328 mW is achieved with a pulse duration of 33.2 ps at a repetition rate of 38.86 MHz, corresponding to a maximum single pulse energy of 4.2 nJ. ? 2021 Elsevier Ltd
Accession Number: 20211910318664
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Record 354 of
Title:DNN-Assisted activity classification using fiber interferometer sensor
Author(s):Zhu, Guohao(1); Xu, Wei(2,3); Yu, Cheung Chuen(4); Sun, Wenye(5); Dong, Bo(6); Yu, Changyuan(7,8); Zhao, Wei(2,3,9); Wang, Yishan(2,3,9)
Source: Proceedings of SPIE - The International Society for Optical Engineering Volume: 11894 Issue: DOI: 10.1117/12.2601294 Published: 2021
Abstract:Deep Neural Network (DNN) assisted activity monitoring algorithms are investigated, aiming to discriminate three activity states, including presence without movement, nobody in bed, and presence with movement. The signal is collected from a fiber-based Mach-Zehnder Interferometer (MZI) sensor, which is placed under a 20-cm thick mattress. When people are lying on the mattress, cardiopulmonary activities will lead to the change of the phase difference of the MZI optical fiber sensor. In this paper, three kinds of DNNs are developed to investigate the classification performance, including feedforward neural network (FNN), convolutional neural network (CNN), and long short-Term memory network (LSTM). The accuracy of FNN, CNN and LSTM is 95.14%, 99.01%, and 99.37% within one second, respectively. Moreover, LSTM has low time and space complexity and better performance. The algorithms constructed can obtain high accuracy and robustness with low computational overhead and storage consumption and have broad application prospects. What's more, the MZI optical fiber sensor has many advantages such as low cost and anti-electromagnetic interference, which means that the system can be popular in medical treatment and households. ? COPYRIGHT SPIE. Downloading of the abstract is permitted for personal use only.
Accession Number: 20215211394017
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Record 355 of
Title:Optical design of a light-controlled pulsed x-ray source with photocathode
Author(s):Zhang, Xuehan(1,2); Sheng, Lizhi(1); Qiang, Pengfei(1); Xuan, Hao(1,2); Liu, Yongan(1); Zhao, Baosheng(1)
Source: Proceedings of SPIE - The International Society for Optical Engineering Volume: 12062 Issue: DOI: 10.1117/12.2606631 Published: 2021
Abstract:X-rays have the characteristics of high single photon energy, high frequency, and strong penetrating ability, are widely used in space communication, radiation imaging, medical diagnosis, non-destructive testing, and other fields. The development of X-rays has had a positive impact on broadening the use of the electromagnetic spectrum. As the core component of the X-ray application, high modulation rate, low power consumption, and excellent performance X-ray generators have been a hot research topic for decades. In this paper, a light-controlled pulsed X-ray source is modeled by simulation software. We perform simulation calculations and summary analysis on the effects of cathode structure, focus structure height, and metal anode voltage on the focal spot size, electron transit-time, and transit-time spread. At an operating voltage of 30KV, if the photocathode is 42mm in diameter, the focal spot diameter is about 1.5mm, the electron transit-time is 3.75ns, and the transit-time spread is 895ps when the focusing structure height is 6mm. And if the diameter of the photocathode is 12mm, the focal spot diameter is the smallest when the focusing pole height is 9mm, which is about 0.7mm, as for the time characteristics, the electron transit-time is 4.1ns, and the transit-time spread is 242ps. The results suggest that the light-controlled pulsed X-ray source is expected to be the next-generation source with easy modulation and short X-ray pulse properties. ? COPYRIGHT SPIE. Downloading of the abstract is permitted for personal use only.
Accession Number: 20220211442601
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Record 356 of
Title:The effect of oceanic turbulence on optical receiving systems
Author(s):Sun, Shu-Wei(1,2); Kang, Fu-Zeng(1); Wang, Hao(1,2)
Source: Proceedings of SPIE - The International Society for Optical Engineering Volume: 11763 Issue: DOI: 10.1117/12.2587149 Published: 2021
Abstract:With the development of underwater optical communication, imaging and sensing, studies of the effect of oceanic turbulence on optical receiving systems have received increasing attention and become a research focus. Until now, the effect of atmosphere turbulence on optical receiving systems have studied widely and in depth, but those in oceanic turbulence have been researched seldom. It is known that the atmosphere turbulence is induced by the temperature fluctuation, while the oceanic turbulence is induced by both the temperature fluctuation and the salinity fluctuation. Thus, the behavior of laser propagation through oceanic turbulence is very different from that in atmosphere turbulence.The paper focuses on the influence of phase disturbance of optical signal caused by oceanic turbulence on optical receiving, including the theoretical modeling of couple efficiency of space optical signal into single-mode fiber received by annular aperture and the variance of angle-of-arrival (AOA) fluctuation received by finite aperture. The research shows that the couple efficiency of single-mode fiber and the variance of angle-of-arrival fluctuation in oceanic turbulence depend on propagation distance, receiving aperture and oceanic turbulence parameter. The results obtained in this paper will be useful for optical receiving systems involving oceanic turbulence channels. ? 2021 SPIE
Accession Number: 20211410162170
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Record 357 of
Title:A visible light photon-counting imaging detector based on induction readout
Author(s):Liu, Yong'An(1,2); Liu, Yifan(1,2); Wei, Yonglin(1); Yang, Xianghui(1); Zhang, Ruili(1); Zhao, Hui(1); Tian, Jinshou(1); Sheng, Lizhi(1); Zhao, Baosheng(1)
Source: Proceedings of SPIE - The International Society for Optical Engineering Volume: 11896 Issue: DOI: 10.1117/12.2602541 Published: 2021
Abstract:Photon-counting imaging detectors based on microchannel plate (MCP) and position-sensitive anode are characterized by extremely high sensitivity, as well as the ability to detect single photons. In this study, a visible light photon-counting imaging detector based on induction readout was developed for the detection of weak light intensities, such as photon counting radar and biofluorescence lifetime imaging. The design is based on a 25 mm diameter multi-alkali S20 photocathode followed by a MCP stack, and read out by a high-resistance Ge layer anode. The position-sensitive anode was located at the atmosphere side of the Ge substrate. Such a detector was advantageous in terms of reconfigurability and detachability. The imaging performance of the detector was tested by using the wedge and strip anode to decode the photon event position information. The experimental results showed a detector gain reaching about 3×106, pulse height resolution (PHR) of about 105%, and spatial resolution better than 100μm. ? 2021 SPIE.
Accession Number: 20214911279038
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Record 358 of
Title:Research on the X-ray wavelength division multiplexing technology for blackout region communication
Author(s):LI, YAO(1); SU, TONG(2); SHENG, LIZHI(2); XU, NENG(2); ZHAO, BAOSHENG(2)
Source: Optica Applicata Volume: 50 Issue: 4 DOI: 10.37190/OA200409 Published: 2021
Abstract:After the concept of X-ray communication was proposed, its application in complex electromagnetic environment has received more attention, such as data transmission in re-enter special electromagnetic condition. In this article, a new type of X-ray source was introduced firstly, which was expected to generate multiple characteristic lines and achieve wavelength division multiplexing technology in X-ray band. Then an experimental platform was built for analyzing transmission characteristics of X-ray photon in various plasma media. Finally, the calculation model for a link power equation was given. Experiment results show that transmittance of 8-18 keV X-ray signal is relatively stable, atomic numbers from 29 to 42 are the most suitable materials for wavelength division multiplexing, the X-ray communication system is expected to realize about 200 kbps data transmission rate in adjacent space. ? 2020 Wroc??aw University of Science and Technology. All rights reserved.
Accession Number: 20210609900370
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Record 359 of
Title:Research Progress of Attosecond Pulse Generation and Characterization (Invited)
Author(s):Wang, Hushan(1); Cao, Huabao(1); Pi, Liangwen(1); Huang, Pei(1); Wang, Xianglin(1); Xu, Peng(1); Yuan, Hao(1,2); Liu, Xin(1,2); Wang, Yishan(1); Zhao, Wei(1); Fu, Yuxi(1)
Source: Guangzi Xuebao/Acta Photonica Sinica Volume: 50 Issue: 1 DOI: 10.3788/gzxb20215001.0132001 Published: January 25, 2021
Abstract:Attosecond pulse light source, born at the turn of 21st centruy, is a fully coherent light source with attosecond-temporal and nano-spatial resolution, leading to the remarkable progress and breakthroughs in attosecond science in the past two decades. New research methods and important innovation opportunities in physics, chemistry, biology, materials, information and other fields have emerged with the advent of attoseond pulse. This review surveys the important efforts aimed at developing attosecond pulses, mainly summarizes the key technologies and status of high-order harmonics, attosecond pulse generation and attosecond pulse measurement, and presents the development prospects of attosecond pulse research in the end. ? 2021, Science Press. All right reserved.
Accession Number: 20210809975867
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Record 360 of
Title:Waveguide Optimization and Efficiency Characteristic Analysis of 808 nm Laser Diodes
Author(s):Chang, Yi-Dong(1,2); Wang, Zhen-Fu(2); Zhang, Xiao-Ying(3); Yang, Guo-Wen(2); Li, Te(2); Du, Yu-Qi(1,2); Zhao, Yu-Liang(1,2); Liu, Yu-Xian(1,2); Lan, Yu(1,2)
Source: Faguang Xuebao/Chinese Journal of Luminescence Volume: 42 Issue: 7 DOI: 10.37188/CJL.20210108 Published: July 2021
Abstract:The waveguide thickness of 808 nm InAlGaAs/AlGaAs laser diode chip was optimized in this paper. The study found that when the thickness ratio of the N-waveguide to the P-waveguide was 1.8, the chip had the highest power conversion efficiency. Chip-on-submount(COS) packaged single emitters and fiber-coupled modules@core diameter 62.5 μm, numerical aperture(NA) 0.22 were presented based on this conclusion, and the efficiency characteristic of the devices in the range of -10-90℃ was analyzed. The results showed that when the temperature increased from -10 to 90℃, the carrier leakage ratio of COS single emitter increased from 1.18% to 16.67%, and the carrier leakage ratio of fiber-coupled module increased from 1.99% to 17.73%, indicating that the increase of carrier leakage caused by temperature rise was the main factor leading to the decrease of power conversion efficiency. Moreover, the effects of high-temperature aging, thermal vacuum conditions and space radiation on the power conversion efficiency of fiber-coupled module were studied and the internal factors that lead to the reduction of the device's power conversion efficiency were revealed. ? 2021, Science Press. All right reserved.
Accession Number: 20213010677900
