Pub Date : 2020-11-20DOI: 10.12086/OEE.2020.190366
Yan Yuchen, Ji Yuan, Chen Wendong, Mu Tingzhou, Zhang Chunyan, Ran Feng
When the microLED is in the forward working direction, it is difficult to precisely adjust its voltage to obtain different brightness. Moreover, when the microLED/OLED is turned on, they will be in a closed state for a long time, causing the image display brightness to be deteriorated by the human eye. In order to solve these problems, this paper proposes a dual-frame decentralized fusion scanning strategy to achieve different brightness by adjusting the microLED/OLED on-time. Firstly, the method de-weights the data bits and inserts their on-times into the closed time. Then the data bit weights are double-frame fused after decentralization. Finally, the scanning order of the data bits is redefined. According to the proposed scanning strategy, we designed a scanning controller to drive digital on-silicon microdisplay. The results show that the dual-frame decentralized fusion scan proposed in this paper can accurately adjust the luminance of microLED/OLED and improve the brightness of the image observed by human eyes. Compared with other scanning strategies, the scanning strategy improves the scanning efficiency to 93.75%, the field frequency is increased to 2040 Hz, the scanning clock frequency is 102.36 MHz, and the scanning data bandwidth is reduced. The feasibility of the scan controller is proved by testing at last.
{"title":"Dual-frame decentralized fusion scanning for digital drive on-silicon microdisplays","authors":"Yan Yuchen, Ji Yuan, Chen Wendong, Mu Tingzhou, Zhang Chunyan, Ran Feng","doi":"10.12086/OEE.2020.190366","DOIUrl":"https://doi.org/10.12086/OEE.2020.190366","url":null,"abstract":"When the microLED is in the forward working direction, it is difficult to precisely adjust its voltage to obtain different brightness. Moreover, when the microLED/OLED is turned on, they will be in a closed state for a long time, causing the image display brightness to be deteriorated by the human eye. In order to solve these problems, this paper proposes a dual-frame decentralized fusion scanning strategy to achieve different brightness by adjusting the microLED/OLED on-time. Firstly, the method de-weights the data bits and inserts their on-times into the closed time. Then the data bit weights are double-frame fused after decentralization. Finally, the scanning order of the data bits is redefined. According to the proposed scanning strategy, we designed a scanning controller to drive digital on-silicon microdisplay. The results show that the dual-frame decentralized fusion scan proposed in this paper can accurately adjust the luminance of microLED/OLED and improve the brightness of the image observed by human eyes. Compared with other scanning strategies, the scanning strategy improves the scanning efficiency to 93.75%, the field frequency is increased to 2040 Hz, the scanning clock frequency is 102.36 MHz, and the scanning data bandwidth is reduced. The feasibility of the scan controller is proved by testing at last.","PeriodicalId":39552,"journal":{"name":"Guangdian Gongcheng/Opto-Electronic Engineering","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2020-11-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80745697","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-11-20DOI: 10.12086/OEE.2020.190713
Xun Tianrong, Ruan Yong, Zhao Zhiqiang, Wang Zongyou, T. Tao
For an optic-electro tracking system, an image sensor such as charge-coupled device (CCD) cannot provide target trajectories except for line-of-sight (LOS) error. Thus, it is difficult to achieve direct feedforward control for the tracking loop, which determines the closed-loop performance. An error-based observer (EBO) control of a CCD-based tracking loop is proposed to enhance the tracking performance for an optic-electro tracking system on moving platforms. The EBO control can be plugged into an existing feedback control loop. The closed-loop performance of the CCD-based control system can be improved by optimizing the feedforward filter Q(s). Because this EBO method relies only on the final LOS error, it benefits the control system both in disturbance suppression and target tracking and it can be applied to an optic-electro tracking system in moving platforms as well as in ground platforms. An optimal Q31 filter rather than a low-pass filter is improved for this EBO control. Simulations and experiments show that the tracking performance is effectively enhanced in low frequency compared to traditional control methods.
{"title":"Error-based observer control of an optic-electro tracking control system","authors":"Xun Tianrong, Ruan Yong, Zhao Zhiqiang, Wang Zongyou, T. Tao","doi":"10.12086/OEE.2020.190713","DOIUrl":"https://doi.org/10.12086/OEE.2020.190713","url":null,"abstract":"For an optic-electro tracking system, an image sensor such as charge-coupled device (CCD) cannot provide target trajectories except for line-of-sight (LOS) error. Thus, it is difficult to achieve direct feedforward control for the tracking loop, which determines the closed-loop performance. An error-based observer (EBO) control of a CCD-based tracking loop is proposed to enhance the tracking performance for an optic-electro tracking system on moving platforms. The EBO control can be plugged into an existing feedback control loop. The closed-loop performance of the CCD-based control system can be improved by optimizing the feedforward filter Q(s). Because this EBO method relies only on the final LOS error, it benefits the control system both in disturbance suppression and target tracking and it can be applied to an optic-electro tracking system in moving platforms as well as in ground platforms. An optimal Q31 filter rather than a low-pass filter is improved for this EBO control. Simulations and experiments show that the tracking performance is effectively enhanced in low frequency compared to traditional control methods.","PeriodicalId":39552,"journal":{"name":"Guangdian Gongcheng/Opto-Electronic Engineering","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2020-11-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81550401","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Water-jet guided laser (WJGL) machining is a novel processing technology using water beam fibers to guide the laser to machine the work-piece surface. This processing technology has the advantage of almost no mi-cro-cracks, small heat-affected zone, pollution-free, less recast layer, high processing accuracy, parallel cuffing, etc. This work aims to investigate the effect of different WGLM parameters on the micro-morphology of materials and the mechanism between lasers and materials. The experiments for slotting and grooving 316L stainless steel thin samples were used by the WGLM system developed by our research group in this work. The 2D micro-topography after experiments were tested by the Zeiss Vert.A1 metalloscope, and the 3D micro-topography of samples after experiments were tested by the Leica DVM6 optical microscope with the large depth of field & Bruke Contour Elite I white-light interferometer. Experimental results show that a certain width deposition layer can be occurred in the machining region, and the width of deposition layers does not change with the parameter of the machining time and the number of machining times. From the 2D micro-topography of samples, it can be found that the ‘dr’ of slotting samples and the ‘wl’ of grooving samples also do not change with the machining parameters. From the 3D micro-topography of grooving samples, it can be found that the cross-section shape is inverted trapezoid.
{"title":"Effect of water-guided laser machining technology on micro-morphology of 316L stainless steel","authors":"Yu Yongfei, Qiao Hongchao, Cao Zhihe, Zhao Jibin, Zhang Yinuo, Wu Jiajun","doi":"10.12086/OEE.2020.190654","DOIUrl":"https://doi.org/10.12086/OEE.2020.190654","url":null,"abstract":"Water-jet guided laser (WJGL) machining is a novel processing technology using water beam fibers to guide the laser to machine the work-piece surface. This processing technology has the advantage of almost no mi-cro-cracks, small heat-affected zone, pollution-free, less recast layer, high processing accuracy, parallel cuffing, etc. This work aims to investigate the effect of different WGLM parameters on the micro-morphology of materials and the mechanism between lasers and materials. The experiments for slotting and grooving 316L stainless steel thin samples were used by the WGLM system developed by our research group in this work. The 2D micro-topography after experiments were tested by the Zeiss Vert.A1 metalloscope, and the 3D micro-topography of samples after experiments were tested by the Leica DVM6 optical microscope with the large depth of field & Bruke Contour Elite I white-light interferometer. Experimental results show that a certain width deposition layer can be occurred in the machining region, and the width of deposition layers does not change with the parameter of the machining time and the number of machining times. From the 2D micro-topography of samples, it can be found that the ‘dr’ of slotting samples and the ‘wl’ of grooving samples also do not change with the machining parameters. From the 3D micro-topography of grooving samples, it can be found that the cross-section shape is inverted trapezoid.","PeriodicalId":39552,"journal":{"name":"Guangdian Gongcheng/Opto-Electronic Engineering","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2020-11-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90626642","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-11-20DOI: 10.12086/OEE.2020.200010
Hou Yibo, Huo Yiping, Jiang Xueying, Zhouyi Chen, Guo Yiyuan, Ni Qiqiang, Heng Qian, Hao Xiangxiang
Metal surface plasmon has many novel optical properties and important applications, and it is also a research hotspot. In this paper, a crescent cross (CC) nanostructure composed of a crescent and a cross is studied by the finite element method. New plasmon magnetic mode and multiple Fano resonance can be induced by breaking structure symmetry through changing structure parameters. Meanwhile, by changing the angle between the two rods symmetrically, the figure of merit (FOM) can reach 61. Our structure has important applications in the fields of multi-wavelength sensor, ultra-sensitive biosensor, surface enhanced spectroscopy, and slow light transmission.
{"title":"Generation of multiple Fano resonance and high FOM resonance based on the crescent cross nanostructure","authors":"Hou Yibo, Huo Yiping, Jiang Xueying, Zhouyi Chen, Guo Yiyuan, Ni Qiqiang, Heng Qian, Hao Xiangxiang","doi":"10.12086/OEE.2020.200010","DOIUrl":"https://doi.org/10.12086/OEE.2020.200010","url":null,"abstract":"Metal surface plasmon has many novel optical properties and important applications, and it is also a research hotspot. In this paper, a crescent cross (CC) nanostructure composed of a crescent and a cross is studied by the finite element method. New plasmon magnetic mode and multiple Fano resonance can be induced by breaking structure symmetry through changing structure parameters. Meanwhile, by changing the angle between the two rods symmetrically, the figure of merit (FOM) can reach 61. Our structure has important applications in the fields of multi-wavelength sensor, ultra-sensitive biosensor, surface enhanced spectroscopy, and slow light transmission.","PeriodicalId":39552,"journal":{"name":"Guangdian Gongcheng/Opto-Electronic Engineering","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2020-11-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87870326","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-11-20DOI: 10.12086/OEE.2020.190681
L. Jinhui, Zhou Yilan, Liu Cheng, Shu Xiaowu
The startup error of fiber optic gyroscope (FOG) in north-seeking is the error caused by the zero-bias drift of FOG caused by drastic change of the temperature in the starting process. The start-up error significantly increases north-seeking error during the cold startup phase compared to the stable phase, which prolongs the effective north-seeking time. Through the analysis of the factors affecting the temperature drift of FOG, the mul-ti-parameter linear model was established by empirical mode decomposition (EMD), autoregressive-moving average (ARMA) modeling and Kalman filtering to realize a temperature drift compensation method applied to FOG north-seeking. The experimental results show that the method can reduce the north-seeking startup error by nearly 80%, so that the startup north-seeking precision is equivalent to the stable phase and the effective north-seeking time is shortened.
{"title":"A temperature drift compensation method applied to fiber optic gyroscope north-seeking","authors":"L. Jinhui, Zhou Yilan, Liu Cheng, Shu Xiaowu","doi":"10.12086/OEE.2020.190681","DOIUrl":"https://doi.org/10.12086/OEE.2020.190681","url":null,"abstract":"The startup error of fiber optic gyroscope (FOG) in north-seeking is the error caused by the zero-bias drift of FOG caused by drastic change of the temperature in the starting process. The start-up error significantly increases north-seeking error during the cold startup phase compared to the stable phase, which prolongs the effective north-seeking time. Through the analysis of the factors affecting the temperature drift of FOG, the mul-ti-parameter linear model was established by empirical mode decomposition (EMD), autoregressive-moving average (ARMA) modeling and Kalman filtering to realize a temperature drift compensation method applied to FOG north-seeking. The experimental results show that the method can reduce the north-seeking startup error by nearly 80%, so that the startup north-seeking precision is equivalent to the stable phase and the effective north-seeking time is shortened.","PeriodicalId":39552,"journal":{"name":"Guangdian Gongcheng/Opto-Electronic Engineering","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2020-11-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86051136","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The mainstream target detection network has outstanding target detection capability in high quality RGB images, but for infrared images with poor resolution, the target detection performance decreases significantly. In order to improve the performance of infrared target detection in complex scene, the following measures are adopted in this paper: Firstly, by referring to the field adaption and adopting the appropriate infrared image preprocessing means, the infrared image is closer to the RGB image, so that the mainstream target detection network can further improve the detection accuracy. Secondly, based on the one-stage target detection network YOLOv3, the algorithm replaces the original MSE loss function with the GIOU loss function. It is verified by experiments that the detection accuracy on the open infrared data set the FLIR is significantly improved. Thirdly, in view of the problem of large target size span existing in FLIR dataset, the SPP module is added with reference to the idea of the spatial pyramid to enrich the expression ability of feature map, expand the receptive field of feature map, and further improve the accuracy of target detection.
{"title":"Infrared target detection and recognition in complex scene","authors":"Zhang Ruzhen, Zhang Jianlin, Qi Xiaoping, Zuo Hao-rui, Xu Zhiyong","doi":"10.12086/OEE.2020.200314","DOIUrl":"https://doi.org/10.12086/OEE.2020.200314","url":null,"abstract":"The mainstream target detection network has outstanding target detection capability in high quality RGB images, but for infrared images with poor resolution, the target detection performance decreases significantly. In order to improve the performance of infrared target detection in complex scene, the following measures are adopted in this paper: Firstly, by referring to the field adaption and adopting the appropriate infrared image preprocessing means, the infrared image is closer to the RGB image, so that the mainstream target detection network can further improve the detection accuracy. Secondly, based on the one-stage target detection network YOLOv3, the algorithm replaces the original MSE loss function with the GIOU loss function. It is verified by experiments that the detection accuracy on the open infrared data set the FLIR is significantly improved. Thirdly, in view of the problem of large target size span existing in FLIR dataset, the SPP module is added with reference to the idea of the spatial pyramid to enrich the expression ability of feature map, expand the receptive field of feature map, and further improve the accuracy of target detection.","PeriodicalId":39552,"journal":{"name":"Guangdian Gongcheng/Opto-Electronic Engineering","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2020-10-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75589953","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-10-30DOI: 10.12086/OEE.2020.200203
L. Fengwei, Wu Yongqian, Chengwen Qiang, Liu Hai-tao, Yan Fengtao, Zhang Shiyang, W. Yongjian, Wu Fan
The aspheric surface can correct the system aberration and improve the image quality in the optical imaging system, in addition to that it can simplify the system structure significantly; On the other hand, the resolution of imaging system can be increased by improving the system aperture. Therefore, in the domain of basic scientific research, astronomical cosmological exploration and military defense security the large-aperture aspheric mirrors are all highly required. The manufacturing of large-aperture aspheric mirrors plays a critical role in modern optical engineering. This paper focuses on the advanced manufacturing techniques of large-aperture aspheric mirrors. The optical manufacturing technologies, especially the grinding and polishing techniques of large-aperture aspheric mirrors in the past half century and the surface shape testing methods during the grinding and polishing process, are reviewed. In particular, it summarizes the technical characteristics of advanced (new generation) optical manufacturing, and looks forward to the future manufacturing strategy of large-diameter aspheric mirrors.
{"title":"Overview of advanced manufacturing technology of large-aperture aspheric mirror","authors":"L. Fengwei, Wu Yongqian, Chengwen Qiang, Liu Hai-tao, Yan Fengtao, Zhang Shiyang, W. Yongjian, Wu Fan","doi":"10.12086/OEE.2020.200203","DOIUrl":"https://doi.org/10.12086/OEE.2020.200203","url":null,"abstract":"The aspheric surface can correct the system aberration and improve the image quality in the optical imaging system, in addition to that it can simplify the system structure significantly; On the other hand, the resolution of imaging system can be increased by improving the system aperture. Therefore, in the domain of basic scientific research, astronomical cosmological exploration and military defense security the large-aperture aspheric mirrors are all highly required. The manufacturing of large-aperture aspheric mirrors plays a critical role in modern optical engineering. This paper focuses on the advanced manufacturing techniques of large-aperture aspheric mirrors. The optical manufacturing technologies, especially the grinding and polishing techniques of large-aperture aspheric mirrors in the past half century and the surface shape testing methods during the grinding and polishing process, are reviewed. In particular, it summarizes the technical characteristics of advanced (new generation) optical manufacturing, and looks forward to the future manufacturing strategy of large-diameter aspheric mirrors.","PeriodicalId":39552,"journal":{"name":"Guangdian Gongcheng/Opto-Electronic Engineering","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2020-10-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86304019","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-10-30DOI: 10.12086/OEE.2020.200366
Z. Fei, Yinghui Guo, M. Pu, Li Xiong, Xiaoliang Ma, Xiangang Luo
Photonic spin-orbit interaction is an important phenomenon ignored by classical optics. In recent years, studies have found that this phenomenon can be significantly enhanced by artificial subwavelength structures and adjusted on demand. Traditional metasurfaces only support symmetric photon spin-orbit interactions, and there are limitations in conjugate symmetry, which makes it difficult to use different spin states for multifunctional integration, complex optical field regulation, information encryption, and storage. The asymmetric photon spin-orbit interaction can decouple left and right circularly polarized light, which brings new opportunities for breaking the above-mentioned theoretical and application limitations. This article first introduces the principle and realization method of asymmetric photon spin-orbit interactions, secondly introduces the representative applications and characteristics of asymmetric photon-spin-orbit interactions, and finally outlines the challenges and prospects of asymmetric photon spin-orbit interactions for future research directions.
{"title":"Metasurfaces enabled by asymmetric photonic spin-orbit interactions","authors":"Z. Fei, Yinghui Guo, M. Pu, Li Xiong, Xiaoliang Ma, Xiangang Luo","doi":"10.12086/OEE.2020.200366","DOIUrl":"https://doi.org/10.12086/OEE.2020.200366","url":null,"abstract":"Photonic spin-orbit interaction is an important phenomenon ignored by classical optics. In recent years, studies have found that this phenomenon can be significantly enhanced by artificial subwavelength structures and adjusted on demand. Traditional metasurfaces only support symmetric photon spin-orbit interactions, and there are limitations in conjugate symmetry, which makes it difficult to use different spin states for multifunctional integration, complex optical field regulation, information encryption, and storage. The asymmetric photon spin-orbit interaction can decouple left and right circularly polarized light, which brings new opportunities for breaking the above-mentioned theoretical and application limitations. This article first introduces the principle and realization method of asymmetric photon spin-orbit interactions, secondly introduces the representative applications and characteristics of asymmetric photon-spin-orbit interactions, and finally outlines the challenges and prospects of asymmetric photon spin-orbit interactions for future research directions.","PeriodicalId":39552,"journal":{"name":"Guangdian Gongcheng/Opto-Electronic Engineering","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2020-10-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"72831460","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-10-30DOI: 10.12086/OEE.2020.200317
Hu Rui, Chen Zhi-qiang, Zhang Yuanyuan, X. Tao, Liu Hong, Zhang Ji-you
In terms of the strict design requirements of Ф1.05 m primary mirrors for space optical systems, a new method of structural optimization design of lightweight mirrors is proposed, and a platform for automatic simulation analysis and optimization design of mirror structures are established. The primary mirror design with excellent per-formances is determined based on that platform. The primary mirror weighs less than 50 kg, and the lightweight ratio is close to the foreign advanced level. The first mode frequency of the primary mirror under the support of three spherical hinges is 361.2 Hz, and the first-order non-zero free modal frequency is 501.9 Hz. Under the uniform temperature change of 1 ℃, the surface figures with defocus and without defocus are 0.55 nm RMS and 0.10 nm RMS, respectively. The maximum stress of the primary mirror under 30g overload acceleration is 16.1 MPa. All of these performances meet the design requirements. The most advanced third-generation large-aperture mirror processing technology is adopted, and the route is ultra-precision milling, CNC grinding and polishing of small grinding head, and ion beam finishing. In order to ensure the consistency of surface shape test results no matter in the space or on the ground, the gravity unloading technology, and surface shape error data post-processing technology are developed to eliminate the influence of gravity and other systematic errors. The final surface shape accuracy of the primary mirror reaches 0.011 λ RMS, which shows a high precision optical surface and demonstrates the rationality of the scheme.
{"title":"Design and manufacture of Φ1.05 m lightweight mirror","authors":"Hu Rui, Chen Zhi-qiang, Zhang Yuanyuan, X. Tao, Liu Hong, Zhang Ji-you","doi":"10.12086/OEE.2020.200317","DOIUrl":"https://doi.org/10.12086/OEE.2020.200317","url":null,"abstract":"In terms of the strict design requirements of Ф1.05 m primary mirrors for space optical systems, a new method of structural optimization design of lightweight mirrors is proposed, and a platform for automatic simulation analysis and optimization design of mirror structures are established. The primary mirror design with excellent per-formances is determined based on that platform. The primary mirror weighs less than 50 kg, and the lightweight ratio is close to the foreign advanced level. The first mode frequency of the primary mirror under the support of three spherical hinges is 361.2 Hz, and the first-order non-zero free modal frequency is 501.9 Hz. Under the uniform temperature change of 1 ℃, the surface figures with defocus and without defocus are 0.55 nm RMS and 0.10 nm RMS, respectively. The maximum stress of the primary mirror under 30g overload acceleration is 16.1 MPa. All of these performances meet the design requirements. The most advanced third-generation large-aperture mirror processing technology is adopted, and the route is ultra-precision milling, CNC grinding and polishing of small grinding head, and ion beam finishing. In order to ensure the consistency of surface shape test results no matter in the space or on the ground, the gravity unloading technology, and surface shape error data post-processing technology are developed to eliminate the influence of gravity and other systematic errors. The final surface shape accuracy of the primary mirror reaches 0.011 λ RMS, which shows a high precision optical surface and demonstrates the rationality of the scheme.","PeriodicalId":39552,"journal":{"name":"Guangdian Gongcheng/Opto-Electronic Engineering","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2020-10-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81719202","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-10-30DOI: 10.12086/OEE.2020.200265
Liu Bo, Jiang Shuo, Yu Yang, Chen Zhen
Photon counting LiDAR plays an important role in the long-distance target measurement because of the high detection sensitivity. For the targets with high radial velocity and long distance, ordinary photon counting LiDAR could not recover the useful echo information simply by statistical histogram. In order to solve this problem, a method based on macro/sub-pulse coded photon counting LiDAR is proposed. The flight time of the subpulses is extracted by time shift pulse accumulation and the target distance information is obtained in one macro pulse. In this paper, the theoretical model of macro/sub-pulse coded photon counting LiDAR is established, and the influence of false alarm probability and detection probability is analyzed. The effectiveness of the LiDAR is verified by Monte Carlo simulation and actual experiments.
{"title":"Macro/sub-pulse coded photon counting LiDAR","authors":"Liu Bo, Jiang Shuo, Yu Yang, Chen Zhen","doi":"10.12086/OEE.2020.200265","DOIUrl":"https://doi.org/10.12086/OEE.2020.200265","url":null,"abstract":"Photon counting LiDAR plays an important role in the long-distance target measurement because of the high detection sensitivity. For the targets with high radial velocity and long distance, ordinary photon counting LiDAR could not recover the useful echo information simply by statistical histogram. In order to solve this problem, a method based on macro/sub-pulse coded photon counting LiDAR is proposed. The flight time of the subpulses is extracted by time shift pulse accumulation and the target distance information is obtained in one macro pulse. In this paper, the theoretical model of macro/sub-pulse coded photon counting LiDAR is established, and the influence of false alarm probability and detection probability is analyzed. The effectiveness of the LiDAR is verified by Monte Carlo simulation and actual experiments.","PeriodicalId":39552,"journal":{"name":"Guangdian Gongcheng/Opto-Electronic Engineering","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2020-10-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89082457","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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