Aiming at the problems of poor safety, reliability and assembly consistency of manual assembly of large segmented optical components, a dual manipulator automatic assembly method is proposed. First of all, a modular automatic assembly system is built, and the interactive cooperation mode of dual robotic arms is adopted to realize the function exchange of the two robotic arms and meet the requirements of a wider and larger visual identification and assembly range. Then, the 3D spatial grasping and assembly relationship is established by the “point cloud stitching” technology based on marker points, and the system calibration is completed. Finally, a “step-by-step” point-by-point approximation assembly strategy is proposed, which corrects the error through binocular vision guidance to improve the final assembly accuracy, which meets the requirements of high assembly accuracy and strong consistency of large-scale segmented optical components.
{"title":"Research on automatic assembly method of dual manipulator for large-scale segmented optical components","authors":"Pei Li, Jie Wu, Chong Lv, Yue Xiao, Chunrui Zhang","doi":"10.1117/12.3005430","DOIUrl":"https://doi.org/10.1117/12.3005430","url":null,"abstract":"Aiming at the problems of poor safety, reliability and assembly consistency of manual assembly of large segmented optical components, a dual manipulator automatic assembly method is proposed. First of all, a modular automatic assembly system is built, and the interactive cooperation mode of dual robotic arms is adopted to realize the function exchange of the two robotic arms and meet the requirements of a wider and larger visual identification and assembly range. Then, the 3D spatial grasping and assembly relationship is established by the “point cloud stitching” technology based on marker points, and the system calibration is completed. Finally, a “step-by-step” point-by-point approximation assembly strategy is proposed, which corrects the error through binocular vision guidance to improve the final assembly accuracy, which meets the requirements of high assembly accuracy and strong consistency of large-scale segmented optical components.","PeriodicalId":298662,"journal":{"name":"Applied Optics and Photonics China","volume":" 44","pages":"1296409 - 1296409-7"},"PeriodicalIF":0.0,"publicationDate":"2023-12-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138994834","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 Whispering Gallery Modes Resonators(WGMR) are specific electromagnetic modes confined in circular resonators, where light beams are guided along the circumferences of the resonators with very small losses by total internal reflections. WGMR is the core component of optical filters, ultra-narrow linewidth laser, microwave photoelectric oscillator, optical frequency comb, rubidium atomic clock etc and high-precision sensors. Q factor is defined as the ratio of the total energy of photons in WGMR to the loss lost in one propagation cycle. The energy loss of WGMR is discussed. The cutting dynamics model diagram was established based the cutting force model for turning. The key technology affecting WGMR’s Q factor was the fabrication process. The manufacture of ultra-high Q factor WGMR are realized through rough machining, ultra-precision turning and precision polishing. The processing of ultra-precision turning and precision polishing is reported in the paper. The important fabrication processing of WGMR is ultra-precision turning. The test results show that the Q value of WGMR is 1.5×10 9@1550nm by Q value measurement system. The surface roughness and shape error of WGMR are 0.6nm (Ra value) and 5.3nm (PV value) respectively, measured by white light interferometer.
{"title":"Fabrication of millimeter-scale crystal whispering gallery mode resonators","authors":"Junhan Liu, Tianliang Qu, Changxin Xiong","doi":"10.1117/12.3006429","DOIUrl":"https://doi.org/10.1117/12.3006429","url":null,"abstract":"The Whispering Gallery Modes Resonators(WGMR) are specific electromagnetic modes confined in circular resonators, where light beams are guided along the circumferences of the resonators with very small losses by total internal reflections. WGMR is the core component of optical filters, ultra-narrow linewidth laser, microwave photoelectric oscillator, optical frequency comb, rubidium atomic clock etc and high-precision sensors. Q factor is defined as the ratio of the total energy of photons in WGMR to the loss lost in one propagation cycle. The energy loss of WGMR is discussed. The cutting dynamics model diagram was established based the cutting force model for turning. The key technology affecting WGMR’s Q factor was the fabrication process. The manufacture of ultra-high Q factor WGMR are realized through rough machining, ultra-precision turning and precision polishing. The processing of ultra-precision turning and precision polishing is reported in the paper. The important fabrication processing of WGMR is ultra-precision turning. The test results show that the Q value of WGMR is 1.5×10 9@1550nm by Q value measurement system. The surface roughness and shape error of WGMR are 0.6nm (Ra value) and 5.3nm (PV value) respectively, measured by white light interferometer.","PeriodicalId":298662,"journal":{"name":"Applied Optics and Photonics China","volume":" 6","pages":"1296613 - 1296613-6"},"PeriodicalIF":0.0,"publicationDate":"2023-12-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138994919","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 Flexray illumination technology is a crucial resolution enhancement technique for immersion photolithography machines operating at nodes of 28nm and below. The Flexray pupil shaping Module is the key component of this pupil shaping technique. This module enables the generation of arbitrary illumination modes by adjusting the angular spectrum of the beam through a micro mirror array (MMA). To meet the requirements of optical characteristic detection, a multiparameter detection method has been proposed. The optical performance parameters, including polar non-balance, opening angle, azimuth angle, and ellipticity, are simultaneously obtained by imaging the intensity distribution on the pupil plane. Experimental measurements and analysis of illumination shapes using the Flexray Pupil Shaping Module have been conducted. The experimental results demonstrate that this measurement method can be applied to test the performance of the Flexray Pupil Shaping Module in lithography system.
{"title":"Performance measurement of FlexRay pupil shaping module in lithography system","authors":"Zenghui Yang, Fang Zhang, Jingpei Hu, Zhenxin Huang, Aijun Zeng, Huijie Huang","doi":"10.1117/12.3008032","DOIUrl":"https://doi.org/10.1117/12.3008032","url":null,"abstract":"The Flexray illumination technology is a crucial resolution enhancement technique for immersion photolithography machines operating at nodes of 28nm and below. The Flexray pupil shaping Module is the key component of this pupil shaping technique. This module enables the generation of arbitrary illumination modes by adjusting the angular spectrum of the beam through a micro mirror array (MMA). To meet the requirements of optical characteristic detection, a multiparameter detection method has been proposed. The optical performance parameters, including polar non-balance, opening angle, azimuth angle, and ellipticity, are simultaneously obtained by imaging the intensity distribution on the pupil plane. Experimental measurements and analysis of illumination shapes using the Flexray Pupil Shaping Module have been conducted. The experimental results demonstrate that this measurement method can be applied to test the performance of the Flexray Pupil Shaping Module in lithography system.","PeriodicalId":298662,"journal":{"name":"Applied Optics and Photonics China","volume":" 24","pages":"129631M - 129631M-7"},"PeriodicalIF":0.0,"publicationDate":"2023-12-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138994986","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}
In this paper, we develop and demonstrate a proof-of-principle OEO, which features ultra-low phase noise in a Ka frequency band. The prototype of the whole OEO is in a cylindrical form. The optical fibers are wound on the outside, while all the optoelectronic devices are in the center. The fiber transmission noise is suppressed via phase modulation for the power redistribution. The spur-level improvement and steady state operation is guaranteed by dual-loop structure with 8.7 km and 11.6 km fiber spools, respectively. The optical power loss is reduced by the dual-output electro-optical intensity modulator (DEOM) instead of another 50:50 optical coupler. The noise floor for the fiber link from laser intensity and phase noises is suppressed by the balanced photodetector (PD) with specialized working conditions. Performance is investigated in detail. The OEO operates at the frequency of 30 GHz with the spur suppression of 74.6 dBc. The phase noise of -130.7 dBc/Hz (-149.1 dBc/Hz) @1 kHz (10 kHz), respectively, are achieved. The spectral purity is much higher than the current commercial signal source and equipment. Further, the developed OEO is applied to the frequency conversion. The RF signal, to be converted with a frequency of 7 GHz, is coupled into the OEO. Each beat results with OEO are observed clearly. All these results show that OEO has broad prospects in high precision infrastructure and projects.
{"title":"Ultra-low-phase-noise Ka band microwave optoelectronic oscillator and its application in frequency conversion","authors":"Hao Zhang, Caibin Yu, Pengfei Qu, Lijun Sun","doi":"10.1117/12.3007575","DOIUrl":"https://doi.org/10.1117/12.3007575","url":null,"abstract":"In this paper, we develop and demonstrate a proof-of-principle OEO, which features ultra-low phase noise in a Ka frequency band. The prototype of the whole OEO is in a cylindrical form. The optical fibers are wound on the outside, while all the optoelectronic devices are in the center. The fiber transmission noise is suppressed via phase modulation for the power redistribution. The spur-level improvement and steady state operation is guaranteed by dual-loop structure with 8.7 km and 11.6 km fiber spools, respectively. The optical power loss is reduced by the dual-output electro-optical intensity modulator (DEOM) instead of another 50:50 optical coupler. The noise floor for the fiber link from laser intensity and phase noises is suppressed by the balanced photodetector (PD) with specialized working conditions. Performance is investigated in detail. The OEO operates at the frequency of 30 GHz with the spur suppression of 74.6 dBc. The phase noise of -130.7 dBc/Hz (-149.1 dBc/Hz) @1 kHz (10 kHz), respectively, are achieved. The spectral purity is much higher than the current commercial signal source and equipment. Further, the developed OEO is applied to the frequency conversion. The RF signal, to be converted with a frequency of 7 GHz, is coupled into the OEO. Each beat results with OEO are observed clearly. All these results show that OEO has broad prospects in high precision infrastructure and projects.","PeriodicalId":298662,"journal":{"name":"Applied Optics and Photonics China","volume":"7 2","pages":"129661O - 129661O-4"},"PeriodicalIF":0.0,"publicationDate":"2023-12-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138995031","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}
Yuebo Liu, QiuLing Qiu, Wenyuan Liao, Hao Niu, Jiahui Yan, Zongbei Dai, Teng Ma, Shaohua Yang, C. Lai
The HgCdTe Photodiode is the most basic and important unit of HgCdTe IRFPA (Infra-red focal plane array) detectors, which have been widely used in the fields of security, fire protection, remote sensing and deep space detection. For HgCdTe IRFPA, the trapped charges of the HgCdTe material and the ionic charges introduced during the preparation process are the factors, other than environmental stress, that have the greatest impact on IRFPA performance. The trapped charges come from the trap energy level in the HgCdTe material, which exist during the crystal growth process and can be improved by adjusting the growth conditions, but it cannot be completely avoided. The ionic charges introduced during the process are generally concentrated at the interface and surface of the HgCdTe material, which can be reduced by process improvement, but cannot be completely avoided. In order to analyze the mechanism of multiple charges affecting the HgCdTe detector performance, a type of n+ -on-p HgCdTe Photodiode is selected as the object of this work, and the effects of the concentration and distribution of charges on the carrier distribution and energy band structure of the n+ -on-p HgCdTe are analyzed in detail. The introduction of additional net charge relative to an ideal n+ -on-p HgCdTe Photodiode leads to the aggregation or scavenging of local carriers and affects the energy band structure near the charge, creating additional potential barriers or potential wells, which is likely to cause device degradation. On this basis, the optoelectronic properties of the HgCdTe Photodiode have been investigated under infrared radiation at a wavelength of 9.5 μm, as the light I–V characteristics, the dynamic resistance–voltage characteristics, band structure and carrier density distribution. According to the results of this work, the quasi-fixed charges introduced by defects or contamination will directly affect the generation rate of photogenerated carriers and affect the I–V and R–V characteristics of the HgCdTe Photodiode, leading to phenomena such as rising dark currents, decreasing spectral response, and decreasing quantum efficiency.
{"title":"Effect of trapped charges and ionic charges distribution on n+-on-p HgCdTe photodiode properties","authors":"Yuebo Liu, QiuLing Qiu, Wenyuan Liao, Hao Niu, Jiahui Yan, Zongbei Dai, Teng Ma, Shaohua Yang, C. Lai","doi":"10.1117/12.3006193","DOIUrl":"https://doi.org/10.1117/12.3006193","url":null,"abstract":"The HgCdTe Photodiode is the most basic and important unit of HgCdTe IRFPA (Infra-red focal plane array) detectors, which have been widely used in the fields of security, fire protection, remote sensing and deep space detection. For HgCdTe IRFPA, the trapped charges of the HgCdTe material and the ionic charges introduced during the preparation process are the factors, other than environmental stress, that have the greatest impact on IRFPA performance. The trapped charges come from the trap energy level in the HgCdTe material, which exist during the crystal growth process and can be improved by adjusting the growth conditions, but it cannot be completely avoided. The ionic charges introduced during the process are generally concentrated at the interface and surface of the HgCdTe material, which can be reduced by process improvement, but cannot be completely avoided. In order to analyze the mechanism of multiple charges affecting the HgCdTe detector performance, a type of n+ -on-p HgCdTe Photodiode is selected as the object of this work, and the effects of the concentration and distribution of charges on the carrier distribution and energy band structure of the n+ -on-p HgCdTe are analyzed in detail. The introduction of additional net charge relative to an ideal n+ -on-p HgCdTe Photodiode leads to the aggregation or scavenging of local carriers and affects the energy band structure near the charge, creating additional potential barriers or potential wells, which is likely to cause device degradation. On this basis, the optoelectronic properties of the HgCdTe Photodiode have been investigated under infrared radiation at a wavelength of 9.5 μm, as the light I–V characteristics, the dynamic resistance–voltage characteristics, band structure and carrier density distribution. According to the results of this work, the quasi-fixed charges introduced by defects or contamination will directly affect the generation rate of photogenerated carriers and affect the I–V and R–V characteristics of the HgCdTe Photodiode, leading to phenomena such as rising dark currents, decreasing spectral response, and decreasing quantum efficiency.","PeriodicalId":298662,"journal":{"name":"Applied Optics and Photonics China","volume":" 1","pages":"129660W - 129660W-7"},"PeriodicalIF":0.0,"publicationDate":"2023-12-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138994781","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}
We studied the influence of frequency and phase noise of semiconductor laser on the performance of photonics assisted terahertz wave system. The laser spectrum is Lorentzian intrinsic shape when only Gaussian white noise exists. The phase noise of the laser increases with the increase of the Lorentzian spectral linewidth of the laser. When considering 1 f noise, the laser frequency will be superimposed with 1 f noise. The 1 f noise in the low-frequency band will make the reconstructed laser spectrum of the whole frequency noise tend to be non-Lorentzian shape, which has a serious impact on system performance. When the system is affected by the resonance frequency, the side lobes appearing on both sides of the main peak of the laser spectrum also have a certain impact on the system performance. We simulated dual-polarization (DP) 16-ary quadrature amplitude modulation (16QAM) signal transmission up to 60Gbaud on a 50km standard single mode fiber (SSMF) at 300GHz.
我们研究了半导体激光器的频率和相位噪声对光子辅助太赫兹波系统性能的影响。当只有高斯白噪声时，激光光谱呈洛伦兹本征形状。激光器的相位噪声随着激光器洛伦兹光谱线宽的增加而增加。当考虑 1 f 噪声时，激光频率将与 1 f 噪声叠加。低频段的 1 f 噪声会使重构后的激光光谱全频噪声趋向于非洛伦兹形状，从而对系统性能产生严重影响。当系统受到谐振频率的影响时，激光频谱主峰两侧出现的边叶也会对系统性能产生一定的影响。我们模拟了双偏振（DP）16-ary 正交调幅（16QAM）信号在 300GHz 的 50km 标准单模光纤（SSMF）上传输高达 60Gbaud 的情况。
{"title":"Influence of laser phase noise on photonics-aided terahertz wireless communication system","authors":"Zhigang Xin, Jiao Zhang, Min Zhu","doi":"10.1117/12.3005414","DOIUrl":"https://doi.org/10.1117/12.3005414","url":null,"abstract":"We studied the influence of frequency and phase noise of semiconductor laser on the performance of photonics assisted terahertz wave system. The laser spectrum is Lorentzian intrinsic shape when only Gaussian white noise exists. The phase noise of the laser increases with the increase of the Lorentzian spectral linewidth of the laser. When considering 1 f noise, the laser frequency will be superimposed with 1 f noise. The 1 f noise in the low-frequency band will make the reconstructed laser spectrum of the whole frequency noise tend to be non-Lorentzian shape, which has a serious impact on system performance. When the system is affected by the resonance frequency, the side lobes appearing on both sides of the main peak of the laser spectrum also have a certain impact on the system performance. We simulated dual-polarization (DP) 16-ary quadrature amplitude modulation (16QAM) signal transmission up to 60Gbaud on a 50km standard single mode fiber (SSMF) at 300GHz.","PeriodicalId":298662,"journal":{"name":"Applied Optics and Photonics China","volume":" 38","pages":"129660I - 129660I-5"},"PeriodicalIF":0.0,"publicationDate":"2023-12-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138994798","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}
Jin Qin, Shaowei He, Wei Li, Zhiwei Cheng, Weiming Zhu
Water exhibits excellent dielectric constant dispersion and high loss capacity in the microwave frequency range, making it an ideal material for broadband microwave absorbers. In this paper, a broadband water-cube-based metasurface microwave absorber (WMMA) is proposed, which is capable of regulating microwave absorption. The WMMA is comprised of the top layer of water-cube-based metasurface, the middle water absorption medium, and the bottom PMMA substrate. The impedance of the WMMA is determined by the design of the water-cube structure, resulting in a broadband and tunable microwave absorption coefficient. In the Ku band, the absorption intensity of the WMMA can cover the range from 71% to 99% by regulating h and p of the water-cube unit structure with a constant absorption coefficient over a wide frequency band. The broadband and tunable WMMA has the advantages of easy fabrication and low cost, rendering it highly promising for vast applications in the fields of electromagnetic shielding, stealth, and wireless communications.
水在微波频率范围内具有优异的介电常数分散性和高损耗能力，是宽带微波吸收器的理想材料。本文提出了一种能调节微波吸收的宽带水立方元表面微波吸收器（WMMA）。WMMA 由顶层的水立方元表面、中间的水吸收介质和底层的 PMMA 基底组成。WMMA 的阻抗由水立方结构的设计决定，因此具有宽带和可调的微波吸收系数。在 Ku 波段，通过调节水立方单元结构的 h 和 p，WMMA 的吸收强度可覆盖 71% 到 99% 的范围，并且在宽频带内具有恒定的吸收系数。宽带可调 WMMA 具有易于制造和成本低廉的优点，因此在电磁屏蔽、隐身和无线通信领域具有广阔的应用前景。
{"title":"Water-cube-based metasurface for broadband and tunable microwave absorption","authors":"Jin Qin, Shaowei He, Wei Li, Zhiwei Cheng, Weiming Zhu","doi":"10.1117/12.3007619","DOIUrl":"https://doi.org/10.1117/12.3007619","url":null,"abstract":"Water exhibits excellent dielectric constant dispersion and high loss capacity in the microwave frequency range, making it an ideal material for broadband microwave absorbers. In this paper, a broadband water-cube-based metasurface microwave absorber (WMMA) is proposed, which is capable of regulating microwave absorption. The WMMA is comprised of the top layer of water-cube-based metasurface, the middle water absorption medium, and the bottom PMMA substrate. The impedance of the WMMA is determined by the design of the water-cube structure, resulting in a broadband and tunable microwave absorption coefficient. In the Ku band, the absorption intensity of the WMMA can cover the range from 71% to 99% by regulating h and p of the water-cube unit structure with a constant absorption coefficient over a wide frequency band. The broadband and tunable WMMA has the advantages of easy fabrication and low cost, rendering it highly promising for vast applications in the fields of electromagnetic shielding, stealth, and wireless communications.","PeriodicalId":298662,"journal":{"name":"Applied Optics and Photonics China","volume":"176 2","pages":"129640F - 129640F-6"},"PeriodicalIF":0.0,"publicationDate":"2023-12-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138995050","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 misuse of UAVs has spurred the development of Anti-UAV technology. Infrared detector-based UAV tracking technology has become a research hotspot in the field of the Anti-UAV technology, but still faces the problem of tracking failure caused by background interference. To improve the accuracy and stability of infrared UAV tracking in the complex environments, a spatial-temporal joint constraints based infrared UAV tracking algorithm is proposed. First, a feature pyramid-based Siamese backbone is constructed to enhance the capability of feature extraction for infrared UAVs through cross-scale feature fusion. Next, a region proposal network based on spatio-temporal joint constraints is proposed. Under the constraints of template appearance features and target motion information, the location probability distribution of the infrared UAV is predicted in the entire image, and the prior anchor box is guided to focus on the candidate regions, realizing a soft adaptive search region selection mechanism. By focusing the search area, the anti-background interference capability of the local search strategy and the recapture capability of global search strategy are fused, which effectively mitigates the negative sample interference brought by global search and further enhances the discriminability of target features. Finally, the proposed algorithm is evaluated on the Anti-UAV dataset, achieving precision, success rate, and average precision of 89.5%, 64.9%, and 65.6%, respectively, with a tracking speed of 18.5 FPS. Compared with other advanced tracking algorithms, the proposed algorithm obtains better tracking performance and superior tracking performance in complex scenarios such as fast motion, thermal crossover and distractors interference.
{"title":"Spatial-temporal joint constraints based tracking method for infrared UAV","authors":"Xueli Xie, Jianxiang Xi, Ruitao Lu, Xiaogang Yang, Wenxin Xia","doi":"10.1117/12.3006233","DOIUrl":"https://doi.org/10.1117/12.3006233","url":null,"abstract":"The misuse of UAVs has spurred the development of Anti-UAV technology. Infrared detector-based UAV tracking technology has become a research hotspot in the field of the Anti-UAV technology, but still faces the problem of tracking failure caused by background interference. To improve the accuracy and stability of infrared UAV tracking in the complex environments, a spatial-temporal joint constraints based infrared UAV tracking algorithm is proposed. First, a feature pyramid-based Siamese backbone is constructed to enhance the capability of feature extraction for infrared UAVs through cross-scale feature fusion. Next, a region proposal network based on spatio-temporal joint constraints is proposed. Under the constraints of template appearance features and target motion information, the location probability distribution of the infrared UAV is predicted in the entire image, and the prior anchor box is guided to focus on the candidate regions, realizing a soft adaptive search region selection mechanism. By focusing the search area, the anti-background interference capability of the local search strategy and the recapture capability of global search strategy are fused, which effectively mitigates the negative sample interference brought by global search and further enhances the discriminability of target features. Finally, the proposed algorithm is evaluated on the Anti-UAV dataset, achieving precision, success rate, and average precision of 89.5%, 64.9%, and 65.6%, respectively, with a tracking speed of 18.5 FPS. Compared with other advanced tracking algorithms, the proposed algorithm obtains better tracking performance and superior tracking performance in complex scenarios such as fast motion, thermal crossover and distractors interference.","PeriodicalId":298662,"journal":{"name":"Applied Optics and Photonics China","volume":"169 3","pages":"129600A - 129600A-13"},"PeriodicalIF":0.0,"publicationDate":"2023-12-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138995055","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}
Right-angle conical mirror is widely used for wavefront conversion, which can construct a null interferometric optical path to achieve interferometric measurement of the cylindrical full-surface topography. However, the effect of the misalignment error on measurements is very significant, due to the difficulty in adjusting the position and attitude of the right-angle conical mirror and the measured cylindrical surface to the ideal state. The pure tilt misalignment errors will lead to parallel interference fringes. Based on this important finding, we propose a fast separation method of translation and tilt misalignment errors. First, adjust the relative translation of the right-angle conical mirror and the cylinder to be measured until all interference fringes are parallel. Then, perform measurement and remove the regular primary tilt from the result to separate the misalignment error effectively, so that the cylindrical full-surface topography is obtained. Under various misalignment errors, the extreme difference of all the PV values of the cylindrical surfaces measured by our method is less than 0.07λ. Experiments indicate that the proposed method can obtain essentially consistent measurements under different misalignment errors. Furthermore, the method is simple to operate and requires no data processing, laying the foundation for the practical application of cylindrical full-surface interferometry measurement.
{"title":"Fast separation method of misalignment errors for cylindrical full-surface interferometry","authors":"Hui Zhang, Fang Ji, Qian Liu","doi":"10.1117/12.3008115","DOIUrl":"https://doi.org/10.1117/12.3008115","url":null,"abstract":"Right-angle conical mirror is widely used for wavefront conversion, which can construct a null interferometric optical path to achieve interferometric measurement of the cylindrical full-surface topography. However, the effect of the misalignment error on measurements is very significant, due to the difficulty in adjusting the position and attitude of the right-angle conical mirror and the measured cylindrical surface to the ideal state. The pure tilt misalignment errors will lead to parallel interference fringes. Based on this important finding, we propose a fast separation method of translation and tilt misalignment errors. First, adjust the relative translation of the right-angle conical mirror and the cylinder to be measured until all interference fringes are parallel. Then, perform measurement and remove the regular primary tilt from the result to separate the misalignment error effectively, so that the cylindrical full-surface topography is obtained. Under various misalignment errors, the extreme difference of all the PV values of the cylindrical surfaces measured by our method is less than 0.07λ. Experiments indicate that the proposed method can obtain essentially consistent measurements under different misalignment errors. Furthermore, the method is simple to operate and requires no data processing, laying the foundation for the practical application of cylindrical full-surface interferometry measurement.","PeriodicalId":298662,"journal":{"name":"Applied Optics and Photonics China","volume":" 35","pages":"129640P - 129640P-7"},"PeriodicalIF":0.0,"publicationDate":"2023-12-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138963509","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}
Zhuoyun Li, Yang Chen, Qing Wang, Mingbin Yu, Shuxiao Wang, Yan Cai
Applying various functional materials to silicon to enhance the functionality of silicon photonics is a potential solution for silicon photonics platform under the requirement of CMOS compatibility. In this paper, two LN heterogeneous integration platforms have been proposed. One is the integration of LN film with a 220 nm top silicon SOI platform, in which the simulated results demonstrate that the designed modulator has a low half wave-voltage length product of 2.27 V·cm. And the other is the integration of LN film with a 400 nm top silicon nitride on insulator platform, in which the the proposed device achieves a VpiL of 2.58 V·cm and a 3-dB bandwidth of ~130 GHz with 7-mm long modulation region is verified by simulation.
{"title":"Design of MZI electro-optic modulator on lithium niobate heterogeneous integration platforms","authors":"Zhuoyun Li, Yang Chen, Qing Wang, Mingbin Yu, Shuxiao Wang, Yan Cai","doi":"10.1117/12.3007772","DOIUrl":"https://doi.org/10.1117/12.3007772","url":null,"abstract":"Applying various functional materials to silicon to enhance the functionality of silicon photonics is a potential solution for silicon photonics platform under the requirement of CMOS compatibility. In this paper, two LN heterogeneous integration platforms have been proposed. One is the integration of LN film with a 220 nm top silicon SOI platform, in which the simulated results demonstrate that the designed modulator has a low half wave-voltage length product of 2.27 V·cm. And the other is the integration of LN film with a 400 nm top silicon nitride on insulator platform, in which the the proposed device achieves a VpiL of 2.58 V·cm and a 3-dB bandwidth of ~130 GHz with 7-mm long modulation region is verified by simulation.","PeriodicalId":298662,"journal":{"name":"Applied Optics and Photonics China","volume":"96 1","pages":"129661U - 129661U-7"},"PeriodicalIF":0.0,"publicationDate":"2023-12-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138965017","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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