Yuming Wang, Hui Zhao, Mingyang Yang, Youshan Qu, XueWu Fan
Traditional imaging lidar exhibits an obvious trade-off between the resolution and the size of its optical system. In order to realize a miniaturized super-resolution (SR) imaging lidar, Fourier ptychography (FP) has been introduced to break through the diffraction limit of the camera lens. FP, derived from synthetic aperture method, is capable of acquiring high resolution and large field-of-view reconstructed images without increasing the aperture size by capturing multiple images with diverse incident angles before computationally combining with phase retrieval algorithm. In this work, a SR imaging lidar system was proposed by using reflective-type FP, which mainly consists of a s-CMOS camera, a Nd:YAG laser, and a 2-D translation stage so as to achieve aperture scanning on the x and y axes. To validate this technique experimentally, a set of images of a positive USAF chrome-on-glass target were obtained for quantitative analysis, and an uneven 1 yuan nickel-on-steel RMB coin was used to simulate the applicability of the SR imaging lidar in practical applications. The observations show that the obtained images based on FP technique have an obvious improvement in resolution, contrast, and clarity. It is worth mentioning that the resolution of these reconstructed images is increased over 3 times in the experiment on the USAF target. Moreover, the images under different apertures were collected, processed and analyzed, which suggest the initial image quality has a non-negligible influence on the reconstructed results. This technique not only improves the performance of the imaging lidar while maintaining low costs, but also bring new vitality in remote image recognition and analysis.
{"title":"Super-resolution imaging lidar based on Fourier ptychography","authors":"Yuming Wang, Hui Zhao, Mingyang Yang, Youshan Qu, XueWu Fan","doi":"10.1117/12.2604172","DOIUrl":"https://doi.org/10.1117/12.2604172","url":null,"abstract":"Traditional imaging lidar exhibits an obvious trade-off between the resolution and the size of its optical system. In order to realize a miniaturized super-resolution (SR) imaging lidar, Fourier ptychography (FP) has been introduced to break through the diffraction limit of the camera lens. FP, derived from synthetic aperture method, is capable of acquiring high resolution and large field-of-view reconstructed images without increasing the aperture size by capturing multiple images with diverse incident angles before computationally combining with phase retrieval algorithm. In this work, a SR imaging lidar system was proposed by using reflective-type FP, which mainly consists of a s-CMOS camera, a Nd:YAG laser, and a 2-D translation stage so as to achieve aperture scanning on the x and y axes. To validate this technique experimentally, a set of images of a positive USAF chrome-on-glass target were obtained for quantitative analysis, and an uneven 1 yuan nickel-on-steel RMB coin was used to simulate the applicability of the SR imaging lidar in practical applications. The observations show that the obtained images based on FP technique have an obvious improvement in resolution, contrast, and clarity. It is worth mentioning that the resolution of these reconstructed images is increased over 3 times in the experiment on the USAF target. Moreover, the images under different apertures were collected, processed and analyzed, which suggest the initial image quality has a non-negligible influence on the reconstructed results. This technique not only improves the performance of the imaging lidar while maintaining low costs, but also bring new vitality in remote image recognition and analysis.","PeriodicalId":236529,"journal":{"name":"International Symposium on Advanced Optical Manufacturing and Testing Technologies (AOMATT)","volume":"35 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-12-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127683973","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}
Yangyi Liu, N. Gu, Cheng Li, Lianhui Zheng, C. Rao
This paper focuses on the optimization of heat dissipation efficiency in heat-stop of large ground-based solar telescope. The cooling structure of multi-channel loop cooling system for solar telescope CLST with 1.8 meters’ aperture is designed and built in Ansys-CFX software based on computational fluid dynamics. During the optimized simulation of the models, number and position of inlets, coolant flow rate and maximum temperature are taken as variables, constraint and objective respectively. In case of same coolant flow rate, more numbers of inlets and position of inlets are closer to the axis of heat-stop, the maximum temperature on the heat-stop decreases. In the design of CLST heat-stop cooling structure, after arrangement of the number and position of inlets in heat-stop cooling structure, its cooling efficiency increases by 35 percent.
{"title":"Optimized thermal design of heat-stop of large ground-based solar telescope CLST","authors":"Yangyi Liu, N. Gu, Cheng Li, Lianhui Zheng, C. Rao","doi":"10.1117/12.2626171","DOIUrl":"https://doi.org/10.1117/12.2626171","url":null,"abstract":"This paper focuses on the optimization of heat dissipation efficiency in heat-stop of large ground-based solar telescope. The cooling structure of multi-channel loop cooling system for solar telescope CLST with 1.8 meters’ aperture is designed and built in Ansys-CFX software based on computational fluid dynamics. During the optimized simulation of the models, number and position of inlets, coolant flow rate and maximum temperature are taken as variables, constraint and objective respectively. In case of same coolant flow rate, more numbers of inlets and position of inlets are closer to the axis of heat-stop, the maximum temperature on the heat-stop decreases. In the design of CLST heat-stop cooling structure, after arrangement of the number and position of inlets in heat-stop cooling structure, its cooling efficiency increases by 35 percent.","PeriodicalId":236529,"journal":{"name":"International Symposium on Advanced Optical Manufacturing and Testing Technologies (AOMATT)","volume":"86 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-12-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127926830","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}
Kewei Chen, Dan Jia, Zhongliang Ying, Zhige Zhang, Nian Pan, Jinlong Huang, Kunpeng Wang, L. Xue
The 1.2-m primary mirror supporting systems are composed of axial support system with whiffletree structure and lateral support system with 6 tangent links. With the simulation based on the finite element analysis (FEA), the 18 points positions of the axial support are determined and the bottom chamber structure of the primary mirror is improved. In order to reduce the mirror surface deformation, the assembly stress on the primary mirror is reduced by optimizing the lateral support structure. The analysis results demonstrated that the root-mean-square (RMS) of the surface deformation is 10.9nm when the primary mirror points vertically. Meanwhile the RMS of the surface deformation is 10.3nm when the primary mirror points horizontally.
{"title":"Design and optimization of 1.2-m primary mirror supporting systems","authors":"Kewei Chen, Dan Jia, Zhongliang Ying, Zhige Zhang, Nian Pan, Jinlong Huang, Kunpeng Wang, L. Xue","doi":"10.1117/12.2604579","DOIUrl":"https://doi.org/10.1117/12.2604579","url":null,"abstract":"The 1.2-m primary mirror supporting systems are composed of axial support system with whiffletree structure and lateral support system with 6 tangent links. With the simulation based on the finite element analysis (FEA), the 18 points positions of the axial support are determined and the bottom chamber structure of the primary mirror is improved. In order to reduce the mirror surface deformation, the assembly stress on the primary mirror is reduced by optimizing the lateral support structure. The analysis results demonstrated that the root-mean-square (RMS) of the surface deformation is 10.9nm when the primary mirror points vertically. Meanwhile the RMS of the surface deformation is 10.3nm when the primary mirror points horizontally.","PeriodicalId":236529,"journal":{"name":"International Symposium on Advanced Optical Manufacturing and Testing Technologies (AOMATT)","volume":"14 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-12-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132617187","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}
Cavity enhanced absorption spectroscopy (CEAS) technology is one of the new types laser absorption spectroscopy technique with high sensitivity and relatively simple detection principle, which is developing rapidly and becoming more and more popular in the field of trace gas detection. A scheme of high sensitivity infrared optical feedback cavity enhanced absorption spectroscopy system is established, based on the high quality optical passive resonator made of ultralow expansion coefficient glass-ceramics, combined with the optical feedback effect of semiconductor laser which can narrow the output laser linewidth and stabilize the laser frequency. The spectral scanning of the system is realized by simultaneously scanning the cavity length of the resonator and tuning the laser current, and the spectral resolution of 0.003 cm-1 and the noise equivalent absorption sensitivity are better than 2×10-9 cm-1Hz-1/2. The system is expected to be applied to real-time analysis of respiratory gas and realize the application of the technology in human breath diagnosis.
{"title":"A scheme for trace gas detection using infrared optical feedback cavity enhanced spectroscopy","authors":"Shiyu Guan, Huilin Cao, Yucheng Ouyang, Z. Tan","doi":"10.1117/12.2605380","DOIUrl":"https://doi.org/10.1117/12.2605380","url":null,"abstract":"Cavity enhanced absorption spectroscopy (CEAS) technology is one of the new types laser absorption spectroscopy technique with high sensitivity and relatively simple detection principle, which is developing rapidly and becoming more and more popular in the field of trace gas detection. A scheme of high sensitivity infrared optical feedback cavity enhanced absorption spectroscopy system is established, based on the high quality optical passive resonator made of ultralow expansion coefficient glass-ceramics, combined with the optical feedback effect of semiconductor laser which can narrow the output laser linewidth and stabilize the laser frequency. The spectral scanning of the system is realized by simultaneously scanning the cavity length of the resonator and tuning the laser current, and the spectral resolution of 0.003 cm-1 and the noise equivalent absorption sensitivity are better than 2×10-9 cm-1Hz-1/2. The system is expected to be applied to real-time analysis of respiratory gas and realize the application of the technology in human breath diagnosis.","PeriodicalId":236529,"journal":{"name":"International Symposium on Advanced Optical Manufacturing and Testing Technologies (AOMATT)","volume":"49 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-12-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114602251","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}
Magnetorheological finishing (MRF) has been widely used in the field of modern optical machining due to the high certainty of processing. In the processing of spherical components, the detection means and sample preparation limit the acquisition of magnetorheological spherical tool influence function. In order to realize the high precision manufacturing of spherical components, the spherical removal function in the magneto-rheological polishing process is simulated and applied in practice. Based on the Preston equation, the material removal of the planar component was analyzed and the plane tool influence function model was established. On this basis, the correlation between spherical removal and plane removal was analyzed, and a simplified spherical tool influence function simulation method was proposed, and its accuracy was verified by experiments. Aiming at the processing of spherical components, the processing technology was improved and the actual processing was carried out. After processing, the PV value of the transmitted wavefront was 0.09λ, and the RMS value was 3.2 nm. The experimental results show that the spherical tool influence function simulated in this paper can be applied in actual processing and obtain a high-quality optical surface.
{"title":"Simulation and application of spherical tool influence function for magnetorheological finishing","authors":"Hong-xiang Wang, Shiwei Liu, Qing-hua Zhang, Jing Hou, Xianhua Chen","doi":"10.1117/12.2603930","DOIUrl":"https://doi.org/10.1117/12.2603930","url":null,"abstract":"Magnetorheological finishing (MRF) has been widely used in the field of modern optical machining due to the high certainty of processing. In the processing of spherical components, the detection means and sample preparation limit the acquisition of magnetorheological spherical tool influence function. In order to realize the high precision manufacturing of spherical components, the spherical removal function in the magneto-rheological polishing process is simulated and applied in practice. Based on the Preston equation, the material removal of the planar component was analyzed and the plane tool influence function model was established. On this basis, the correlation between spherical removal and plane removal was analyzed, and a simplified spherical tool influence function simulation method was proposed, and its accuracy was verified by experiments. Aiming at the processing of spherical components, the processing technology was improved and the actual processing was carried out. After processing, the PV value of the transmitted wavefront was 0.09λ, and the RMS value was 3.2 nm. The experimental results show that the spherical tool influence function simulated in this paper can be applied in actual processing and obtain a high-quality optical surface.","PeriodicalId":236529,"journal":{"name":"International Symposium on Advanced Optical Manufacturing and Testing Technologies (AOMATT)","volume":"6 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-12-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122184944","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}
Perovskite has attracted enormous research interest due to the unique advantages, such as high absorption coefficient, great carrier mobility, low exciton binding energy, etc., providing desirable applications in high-performance perovskite solar cells (PSCs). However, the current density-voltage (J-V) hysteresis phenomenon in PSC will reduce the testing accuracy and weaken the actual device performance. In this paper, a facile method based on interfacial engineering is proposed to suppress the hysteresis phenomenon and the deeper physicochemical mechanism is systematically analyzed. By incorporating non-fullerene acceptor Y6 in the crystallization process, a denser and continuous perovskite film with a low-density defect state is obtained, which affords PSC dramatically suppressed the J-V hysteresis with the hysteresis difference decreasing from 13.6% to 1.9% at the maximum power point. Furthermore, scanning electron microscope results and energy dispersive spectrum mappings suggest that ultrathin Y6 film is deposited between the perovskite film and the hydrophobic electron transport layer of PC61BM. The improvement of wettability and matching energy level caused by Y6, render the photocurrent increase and the power conversion efficiency of PSC@Y6 high up to 17.5%. Thus, this work demonstrates that interfacial engineering using small-molecule non-fullerene acceptor is a promising strategy to suppress the J-V hysteresis limiting further PSC commercialization.
{"title":"Suppressed J-V hysteresis in highly efficient inverted perovskite solar cells using small-molecule non-fullerene acceptor","authors":"Mengge Wu, Pu Fan, S. Hou, Junsheng Yu","doi":"10.1117/12.2603928","DOIUrl":"https://doi.org/10.1117/12.2603928","url":null,"abstract":"Perovskite has attracted enormous research interest due to the unique advantages, such as high absorption coefficient, great carrier mobility, low exciton binding energy, etc., providing desirable applications in high-performance perovskite solar cells (PSCs). However, the current density-voltage (J-V) hysteresis phenomenon in PSC will reduce the testing accuracy and weaken the actual device performance. In this paper, a facile method based on interfacial engineering is proposed to suppress the hysteresis phenomenon and the deeper physicochemical mechanism is systematically analyzed. By incorporating non-fullerene acceptor Y6 in the crystallization process, a denser and continuous perovskite film with a low-density defect state is obtained, which affords PSC dramatically suppressed the J-V hysteresis with the hysteresis difference decreasing from 13.6% to 1.9% at the maximum power point. Furthermore, scanning electron microscope results and energy dispersive spectrum mappings suggest that ultrathin Y6 film is deposited between the perovskite film and the hydrophobic electron transport layer of PC61BM. The improvement of wettability and matching energy level caused by Y6, render the photocurrent increase and the power conversion efficiency of PSC@Y6 high up to 17.5%. Thus, this work demonstrates that interfacial engineering using small-molecule non-fullerene acceptor is a promising strategy to suppress the J-V hysteresis limiting further PSC commercialization.","PeriodicalId":236529,"journal":{"name":"International Symposium on Advanced Optical Manufacturing and Testing Technologies (AOMATT)","volume":"36 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-12-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131492893","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}
Xiaoyang Li, Xu Yang, Bincheng Li, Shengqian Wang, H. Xian
Segmented telescope is an effective way to realize high-resolution observations in astronomy. An important work for high-resolution observations using segmented telescopes is phasing the segmented primary mirror. Modified Shack-Hartmann sensor. Is proposed for piston error detection. The interference pattern created by a circular lens placed across two adjacent mirrors in exit pupil plane is used as the signal of the modified Shack-Hartmann sensor. Piston errors need to be extracted from the interference pattern. The offset of lens and gap error of adjacent mirrors causes the distortion of interference pattern, and leads to a reduction in the detection accuracy of existing piston error extraction techniques. In this paper, we propose to replace the circular lens with a square lens and the mathematical model of the corresponding interference pattern is modeled by Fourier optics, including the one-dimensional and two-dimensional analytical solution of the interference pattern. The simulation results show that the proposed analytical solution can effectively characterize the interference pattern in the ideal situation and in the presence of lateral offset of the lens and the gap error of the adjacent mirrors situation. The results presented here give a deeper insight into the interference pattern of modified Shack-Hartmann sensor, and are of great help for developing new piston error detection techniques based on modified Shack-Hartmann sensor.
{"title":"Interference pattern with an analytical solution in modified Shack-Hartmann sensor","authors":"Xiaoyang Li, Xu Yang, Bincheng Li, Shengqian Wang, H. Xian","doi":"10.1117/12.2603971","DOIUrl":"https://doi.org/10.1117/12.2603971","url":null,"abstract":"Segmented telescope is an effective way to realize high-resolution observations in astronomy. An important work for high-resolution observations using segmented telescopes is phasing the segmented primary mirror. Modified Shack-Hartmann sensor. Is proposed for piston error detection. The interference pattern created by a circular lens placed across two adjacent mirrors in exit pupil plane is used as the signal of the modified Shack-Hartmann sensor. Piston errors need to be extracted from the interference pattern. The offset of lens and gap error of adjacent mirrors causes the distortion of interference pattern, and leads to a reduction in the detection accuracy of existing piston error extraction techniques. In this paper, we propose to replace the circular lens with a square lens and the mathematical model of the corresponding interference pattern is modeled by Fourier optics, including the one-dimensional and two-dimensional analytical solution of the interference pattern. The simulation results show that the proposed analytical solution can effectively characterize the interference pattern in the ideal situation and in the presence of lateral offset of the lens and the gap error of the adjacent mirrors situation. The results presented here give a deeper insight into the interference pattern of modified Shack-Hartmann sensor, and are of great help for developing new piston error detection techniques based on modified Shack-Hartmann sensor.","PeriodicalId":236529,"journal":{"name":"International Symposium on Advanced Optical Manufacturing and Testing Technologies (AOMATT)","volume":"13 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-12-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133845246","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}
Scanning lidar scans the target region point-by-point and measures the time of flight (TOF) of laser signal at each point to obtain the 3D information of the target surface. By using fixed size of scanning spot, the resolution of reconstructed depth image is consistent with the number of scanning points. Therefore, traditional scanning lidar is hardly to achieve high resolution and scanning efficiency simultaneously. Aimed to address this issue, we propose a method of interested region selection and depth image super-resolution reconstruction. By constructing a simulation target region with 10 m × 10 m, the proposed method is used to scan this region. The position of the interested region is obtained by scanning the full field of view (FOV) with a large spot. Then the interested region with 4 m × 8 m is fine scanned with reduced scanning spot. By using the super-resolution reconstruction method of depth image, the resolution of the depth image obtained by fine scanning with 40 × 80 points is increased by two times. And the depth image of the interested region with 80 × 160 pixels is obtained. The simulation result shows that the lidar based on this method can give consideration to both high scanning efficiency and the resolution of reconstructed depth image.
扫描激光雷达逐点扫描目标区域，测量每个点处激光信号的飞行时间(TOF)，获得目标表面的三维信息。通过使用固定尺寸的扫描点，重建深度图像的分辨率与扫描点的数量一致。因此，传统的扫描激光雷达很难同时实现高分辨率和高扫描效率。针对这一问题，提出了一种兴趣区域选择和深度图像超分辨率重建方法。通过构造一个10 m × 10 m的仿真目标区域，采用该方法对该区域进行扫描。通过大点扫描全视场获得感兴趣区域的位置。然后对4 m × 8 m的感兴趣区域进行精细扫描，缩小扫描点。采用深度图像的超分辨率重建方法，将40 × 80点精细扫描得到的深度图像分辨率提高了2倍。得到感兴趣区域80 × 160像素的深度图像。仿真结果表明，基于该方法的激光雷达能够兼顾高扫描效率和重建深度图像的分辨率。
{"title":"Interested region selection and super-resolution reconstruction of depth image for scanning lidar","authors":"Ao Yang, Jie Cao, Zhijun Li, Yang Cheng, Q. Hao","doi":"10.1117/12.2603943","DOIUrl":"https://doi.org/10.1117/12.2603943","url":null,"abstract":"Scanning lidar scans the target region point-by-point and measures the time of flight (TOF) of laser signal at each point to obtain the 3D information of the target surface. By using fixed size of scanning spot, the resolution of reconstructed depth image is consistent with the number of scanning points. Therefore, traditional scanning lidar is hardly to achieve high resolution and scanning efficiency simultaneously. Aimed to address this issue, we propose a method of interested region selection and depth image super-resolution reconstruction. By constructing a simulation target region with 10 m × 10 m, the proposed method is used to scan this region. The position of the interested region is obtained by scanning the full field of view (FOV) with a large spot. Then the interested region with 4 m × 8 m is fine scanned with reduced scanning spot. By using the super-resolution reconstruction method of depth image, the resolution of the depth image obtained by fine scanning with 40 × 80 points is increased by two times. And the depth image of the interested region with 80 × 160 pixels is obtained. The simulation result shows that the lidar based on this method can give consideration to both high scanning efficiency and the resolution of reconstructed depth image.","PeriodicalId":236529,"journal":{"name":"International Symposium on Advanced Optical Manufacturing and Testing Technologies (AOMATT)","volume":"104 13","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-12-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132477440","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 detecting CCD of a space astronomical telescope needs to be cooled to -75℃ to suppress the dark current for faint target detecting in the universe, and coplanarly spliced with two fine guidance sensor(FGS) which needs to be cooled to -40°C for the stability as long time observation. Two one stage thermos-electric cooler(TEC) was connected to actively cool the detector to ensure the working temperature and the temperature control accuracy, the Structural of the actively cooling detector assembly and the focal plane component were presented and the power dissipation of the TEC was calculated. In order to ensure the coplanarity of the focal plane component on the working temperature, the finite element method was used to analyze the thermal distribution on the detector surface and the thermal deformation of the supporting structure of the FGS with different materials. The analysis results showed that the lowest cooling temperature of the detecting CCD is -75°C, the temperature control accuracy was better than 1°C, and the coplanar error of the detection CCD and the fine guidance sensors did not exceed 20μm. The thermal equilibrium test showed that the lowest cooling temperature was -74.9°C~-75.1°C for the detecting CCD, The temperature control accuracy was 0.1°C. The thermal optical test showed that the defocus of the FGS was 4μm after focusing, which verified the thermal and structural design performance of the focal plane component.
{"title":"Design of the active cooling focal plane component for the space astronomy telescope","authors":"Liang-jie Feng, Chenjie Wang, Gangyi Zou","doi":"10.1117/12.2605265","DOIUrl":"https://doi.org/10.1117/12.2605265","url":null,"abstract":"The detecting CCD of a space astronomical telescope needs to be cooled to -75℃ to suppress the dark current for faint target detecting in the universe, and coplanarly spliced with two fine guidance sensor(FGS) which needs to be cooled to -40°C for the stability as long time observation. Two one stage thermos-electric cooler(TEC) was connected to actively cool the detector to ensure the working temperature and the temperature control accuracy, the Structural of the actively cooling detector assembly and the focal plane component were presented and the power dissipation of the TEC was calculated. In order to ensure the coplanarity of the focal plane component on the working temperature, the finite element method was used to analyze the thermal distribution on the detector surface and the thermal deformation of the supporting structure of the FGS with different materials. The analysis results showed that the lowest cooling temperature of the detecting CCD is -75°C, the temperature control accuracy was better than 1°C, and the coplanar error of the detection CCD and the fine guidance sensors did not exceed 20μm. The thermal equilibrium test showed that the lowest cooling temperature was -74.9°C~-75.1°C for the detecting CCD, The temperature control accuracy was 0.1°C. The thermal optical test showed that the defocus of the FGS was 4μm after focusing, which verified the thermal and structural design performance of the focal plane component.","PeriodicalId":236529,"journal":{"name":"International Symposium on Advanced Optical Manufacturing and Testing Technologies (AOMATT)","volume":"5 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-12-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132733484","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}
Lele Ren, Fei-hu Zhang, D. Liao, R. Xie, Shi-jie Zhao, Jian Wang
The edge roll off seriously restricts the further improvement of the overall surface figure accuracy in CP of large planar optics. Firstly, the half width and depth of large planar optics’ edge region is proposed to quantify the roll off degree by analyzing its radial equivalent profile. Then, a two-dimensional symmetrical model of the large planar optics and the pitch lap is established. Next, based on the finite element model, the influence of extension block’s bonding state on the large planar optics edge’s stress concentration is analyzed. Finally, the effectiveness of this proposed method is verified by CP of large planar optics with extension blocks.
{"title":"Suppressing the edge roll off in continuous polishing of large planar optics by using extension blocks","authors":"Lele Ren, Fei-hu Zhang, D. Liao, R. Xie, Shi-jie Zhao, Jian Wang","doi":"10.1117/12.2604437","DOIUrl":"https://doi.org/10.1117/12.2604437","url":null,"abstract":"The edge roll off seriously restricts the further improvement of the overall surface figure accuracy in CP of large planar optics. Firstly, the half width and depth of large planar optics’ edge region is proposed to quantify the roll off degree by analyzing its radial equivalent profile. Then, a two-dimensional symmetrical model of the large planar optics and the pitch lap is established. Next, based on the finite element model, the influence of extension block’s bonding state on the large planar optics edge’s stress concentration is analyzed. Finally, the effectiveness of this proposed method is verified by CP of large planar optics with extension blocks.","PeriodicalId":236529,"journal":{"name":"International Symposium on Advanced Optical Manufacturing and Testing Technologies (AOMATT)","volume":"44 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-12-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116367834","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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