Metasurfaces can overcome the shortcomings of traditional lenses, such as large volume, heavy weight and difficult aberration correction. However, based on the diffraction principle, metasurfaces have serious chromatic aberration and lower efficiency than traditional glass lenses, so they need to be used with monochromatic laser illumination. Therefore, metasurfaces are the best choice for lidar systems to realize miniaturization and lightweight design. The lidar emitting system usually uses a 905nm pulsed laser diode (PLD) as the light source, which requires two cylindrical lenses to collimate the laser beam in the X and Y directions separately. In this paper, two metasurfaces is designed in different areas of the same substrate to collimate the laser beam. By folding the light path through the right-angle prism, the beam passes through two metasurfaces successively, which are responsible for collimating the rays in the X and Y directions respectively. After collimation, the divergence angles of the rays are less than 0.3°×0.1°. By attaching a microelectro-mechanical system (MEMS) mirror behind the metasurfaces to realize scanning, we can obtain the lidar emitting system. By using metasurfaces to replace the traditional cylindrical lenses, the weight and size of the lidar emitting system can be greatly reduced. With further research on metasurface technology, metasurfaces are expected to replace the traditional lenses and even the scanning device in lidar, so as to realize highly integrated chip-level lidar.
元表面能克服传统透镜体积大、重量重、像差校正困难等缺点。然而，基于衍射原理，元表面具有严重的色差，效率低于传统玻璃透镜，因此需要配合单色激光照明使用。因此，元表面是激光雷达系统实现小型化和轻量化设计的最佳选择。激光雷达发射系统通常使用 905nm 脉冲激光二极管（PLD）作为光源，需要两个圆柱透镜分别在 X 和 Y 方向准直激光束。本文在同一基板的不同区域设计了两个元表面来准直激光束。通过直角棱镜折叠光路，光束先后通过两个元表面，分别负责 X 和 Y 方向的准直。准直后，光线的发散角小于 0.3°×0.1°。通过在元表面后面安装微机电系统（MEMS）反射镜来实现扫描，我们就可以得到激光雷达发射系统。用元表面代替传统的圆柱透镜，可以大大减小激光雷达发射系统的重量和体积。随着元表面技术研究的深入，元表面有望取代激光雷达中的传统透镜甚至扫描装置，从而实现高度集成的芯片级激光雷达。
{"title":"A method of metasurface collimating pulsed laser diode for lidar emission system","authors":"Zewu Liu, Lei Yang, Chengxiang Guo, Hongbo Xie","doi":"10.1117/12.2687862","DOIUrl":"https://doi.org/10.1117/12.2687862","url":null,"abstract":"Metasurfaces can overcome the shortcomings of traditional lenses, such as large volume, heavy weight and difficult aberration correction. However, based on the diffraction principle, metasurfaces have serious chromatic aberration and lower efficiency than traditional glass lenses, so they need to be used with monochromatic laser illumination. Therefore, metasurfaces are the best choice for lidar systems to realize miniaturization and lightweight design. The lidar emitting system usually uses a 905nm pulsed laser diode (PLD) as the light source, which requires two cylindrical lenses to collimate the laser beam in the X and Y directions separately. In this paper, two metasurfaces is designed in different areas of the same substrate to collimate the laser beam. By folding the light path through the right-angle prism, the beam passes through two metasurfaces successively, which are responsible for collimating the rays in the X and Y directions respectively. After collimation, the divergence angles of the rays are less than 0.3°×0.1°. By attaching a microelectro-mechanical system (MEMS) mirror behind the metasurfaces to realize scanning, we can obtain the lidar emitting system. By using metasurfaces to replace the traditional cylindrical lenses, the weight and size of the lidar emitting system can be greatly reduced. With further research on metasurface technology, metasurfaces are expected to replace the traditional lenses and even the scanning device in lidar, so as to realize highly integrated chip-level lidar.","PeriodicalId":149506,"journal":{"name":"SPIE/COS Photonics Asia","volume":"1 1","pages":"127650P - 127650P-10"},"PeriodicalIF":0.0,"publicationDate":"2023-11-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139216651","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}
Yong Hu, Shaoliang Yu, Qingyang Du, Xiaoshun Jiang
We experimentally demonstrated a stimulated Brillouin laser with hybrid modes, utilizing two coupled silica microtoroid cavities. The first cavity consists of paired modes with a frequency difference close, but not exactly equal, to its Brillouin frequency shift. The second cavity has a resonant mode that is close to one of the modes of the first cavity. The strong coupling between the two similar frequency modes induces mode splitting, resulting in the generation of a hybrid paired mode. This hybrid mode comprises one eigenmode from the first cavity and the super-modes of the coupled microtoroids. By finely tuning the coupling strength to match the frequency difference between the paired modes and the Brillouin shift, we achieve Brillouin lasing. Furthermore, the offset of the frequency shifting in the hybrid modes configuration is much smaller than the Brillouin frequency shift, significantly reducing coupling loss and enabling the realization of a lowthreshold Brillouin laser. We experimentally observed a lasing threshold as low as 0.45 mW, which is two orders of magnitude lower than that of the direct super-modes frequency matching method. This novel approach relaxes the strict requirement of exact frequency matching conditions for Brillouin lasing, making it an excellent platform for compact and ultra-low threshold Brillouin lasers.
{"title":"Low threshold Brillouin lasing with hybrid modes of coupled silica microtoroids","authors":"Yong Hu, Shaoliang Yu, Qingyang Du, Xiaoshun Jiang","doi":"10.1117/12.2686831","DOIUrl":"https://doi.org/10.1117/12.2686831","url":null,"abstract":"We experimentally demonstrated a stimulated Brillouin laser with hybrid modes, utilizing two coupled silica microtoroid cavities. The first cavity consists of paired modes with a frequency difference close, but not exactly equal, to its Brillouin frequency shift. The second cavity has a resonant mode that is close to one of the modes of the first cavity. The strong coupling between the two similar frequency modes induces mode splitting, resulting in the generation of a hybrid paired mode. This hybrid mode comprises one eigenmode from the first cavity and the super-modes of the coupled microtoroids. By finely tuning the coupling strength to match the frequency difference between the paired modes and the Brillouin shift, we achieve Brillouin lasing. Furthermore, the offset of the frequency shifting in the hybrid modes configuration is much smaller than the Brillouin frequency shift, significantly reducing coupling loss and enabling the realization of a lowthreshold Brillouin laser. We experimentally observed a lasing threshold as low as 0.45 mW, which is two orders of magnitude lower than that of the direct super-modes frequency matching method. This novel approach relaxes the strict requirement of exact frequency matching conditions for Brillouin lasing, making it an excellent platform for compact and ultra-low threshold Brillouin lasers.","PeriodicalId":149506,"journal":{"name":"SPIE/COS Photonics Asia","volume":"26 1","pages":"127730P - 127730P-3"},"PeriodicalIF":0.0,"publicationDate":"2023-11-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139217640","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}
Based on a high power InGAsP distributed feedback (DFB) semiconductor laser coupling with an ultra-high-Q silicon nitride microring, we proposed a hybrid integration semiconductor laser scheme for realizing high power and narrow linewidth. For such a scheme, the high power DFB laser serves as the light source, whose output is efficiently coupled into the input waveguide port of ultra-high-Q silicon nitride microring through a silicon lens. Under the optical feedback provided by the Rayleigh scattering in the inhomogeneity silicon nitride microring, the laser may be driven into the self-injected locking state, under which the lasing linewidth can be obviously narrowed. The experimental results demonstrate that, adopting such a hybrid integration scheme, the lasing linewidth can be narrowed to 10 kHz and meanwhile the output power is maintained at the level of 20 mW. The hybrid integration semiconductor lasers have application prospects in some fields simultaneously requiring high coherence and high power, such as LiDAR and long-distance coherence communication.
{"title":"High-power and narrow-linewidth semiconductor laser with silicon nitride microring","authors":"Xin Zhang, Yilu Wu, Qingsong Bai, Yuqi Hu, Wei Xiong, Zhengmao Wu, Dan Lu, Jiagui Wu, Guangqiong Xia","doi":"10.1117/12.2688993","DOIUrl":"https://doi.org/10.1117/12.2688993","url":null,"abstract":"Based on a high power InGAsP distributed feedback (DFB) semiconductor laser coupling with an ultra-high-Q silicon nitride microring, we proposed a hybrid integration semiconductor laser scheme for realizing high power and narrow linewidth. For such a scheme, the high power DFB laser serves as the light source, whose output is efficiently coupled into the input waveguide port of ultra-high-Q silicon nitride microring through a silicon lens. Under the optical feedback provided by the Rayleigh scattering in the inhomogeneity silicon nitride microring, the laser may be driven into the self-injected locking state, under which the lasing linewidth can be obviously narrowed. The experimental results demonstrate that, adopting such a hybrid integration scheme, the lasing linewidth can be narrowed to 10 kHz and meanwhile the output power is maintained at the level of 20 mW. The hybrid integration semiconductor lasers have application prospects in some fields simultaneously requiring high coherence and high power, such as LiDAR and long-distance coherence communication.","PeriodicalId":149506,"journal":{"name":"SPIE/COS Photonics Asia","volume":"45 1","pages":"1276405 - 1276405-4"},"PeriodicalIF":0.0,"publicationDate":"2023-11-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139220606","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}
As a snapshot 3D imaging technology, light field imaging is able to obtain the 3D information of objects in a single exposure and widely used in numerous fields. The paper analyzed the 3D imaging principles of defocused light field camera and elaborated the relationships between its performance indexes and structural parameters, then a performance index system of defocused light field camera was established. An image-telecentric optical system of defocused light field camera with wavelength range of 0.4-0.9μm, field-of-view of 24.5°, F-number of 5 was designed detailly. Aimed at the lack of a unified image quality evaluation method for defocused light field camera, it was proposed to add pupil aberration as an additional evaluation index on the basis of classical image quality evaluation. The result indicates that the designed defocused light field camera achieved excellent image quality and all indexes met the requirements.
{"title":"Analysis and design of optical system for the defocused light field cameras","authors":"Weiqi Lu, Jiacheng Zhu, Weimin Shen","doi":"10.1117/12.2689079","DOIUrl":"https://doi.org/10.1117/12.2689079","url":null,"abstract":"As a snapshot 3D imaging technology, light field imaging is able to obtain the 3D information of objects in a single exposure and widely used in numerous fields. The paper analyzed the 3D imaging principles of defocused light field camera and elaborated the relationships between its performance indexes and structural parameters, then a performance index system of defocused light field camera was established. An image-telecentric optical system of defocused light field camera with wavelength range of 0.4-0.9μm, field-of-view of 24.5°, F-number of 5 was designed detailly. Aimed at the lack of a unified image quality evaluation method for defocused light field camera, it was proposed to add pupil aberration as an additional evaluation index on the basis of classical image quality evaluation. The result indicates that the designed defocused light field camera achieved excellent image quality and all indexes met the requirements.","PeriodicalId":149506,"journal":{"name":"SPIE/COS Photonics Asia","volume":"2 1","pages":"127650U - 127650U-6"},"PeriodicalIF":0.0,"publicationDate":"2023-11-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139224011","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}
Qichao Wang, Qiang Zhang, Xinyan Ma, Kun Yin, Hui Yu
Silicon nitride photonic integrated circuits with ultra-low loss are widely used in applications such as telecommunications and optical sensing. However, the radiation loss increases rapidly as the radius is reduced, resulting in large-sized silicon nitride photonic integrated circuits. The weak thermo-optical effect limits the high-efficiency, low-power consumption applications. In this paper, a stepped index waveguide structure is studied to reduce the bending loss by enhancing the mode confinement. A bend with a radius of 30μm is designed using Ansys MODE. Polymer with a high thermo-optic coefficient is used as the cladding of the silicon nitride waveguide to improve the tuning performance of the phase shifter. The grooves around the waveguide also acts as an adiabatic trench to increase the efficiency of the thermal electrode. A π phase shift under thermal tuned power of 7.5mW is achieved with a 300μm long silicon nitride waveguide. Finally, a cascaded silicon nitride micro-ring resonator with radius of 50μm is designed to achieve an efficient filter with a wide tuning range of 116nm. This scheme provides a novel approach for high-density, wide-tunable and miniaturized devices in silicon nitride photonic integrated circuits.
{"title":"Design of a high phase-shift efficiency wide-tuning silicon nitride filter","authors":"Qichao Wang, Qiang Zhang, Xinyan Ma, Kun Yin, Hui Yu","doi":"10.1117/12.2685992","DOIUrl":"https://doi.org/10.1117/12.2685992","url":null,"abstract":"Silicon nitride photonic integrated circuits with ultra-low loss are widely used in applications such as telecommunications and optical sensing. However, the radiation loss increases rapidly as the radius is reduced, resulting in large-sized silicon nitride photonic integrated circuits. The weak thermo-optical effect limits the high-efficiency, low-power consumption applications. In this paper, a stepped index waveguide structure is studied to reduce the bending loss by enhancing the mode confinement. A bend with a radius of 30μm is designed using Ansys MODE. Polymer with a high thermo-optic coefficient is used as the cladding of the silicon nitride waveguide to improve the tuning performance of the phase shifter. The grooves around the waveguide also acts as an adiabatic trench to increase the efficiency of the thermal electrode. A π phase shift under thermal tuned power of 7.5mW is achieved with a 300μm long silicon nitride waveguide. Finally, a cascaded silicon nitride micro-ring resonator with radius of 50μm is designed to achieve an efficient filter with a wide tuning range of 116nm. This scheme provides a novel approach for high-density, wide-tunable and miniaturized devices in silicon nitride photonic integrated circuits.","PeriodicalId":149506,"journal":{"name":"SPIE/COS Photonics Asia","volume":"8 1","pages":"1276406 - 1276406-5"},"PeriodicalIF":0.0,"publicationDate":"2023-11-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139224240","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}
Jiaqi Li, Lin Li, Lihui Wang, Leijin Li, Shaoyong Li
The traditional method of monitoring cameras is employed in robot vision, surveillance cameras, and so on. However, it cannot track as fast as expected due to the large inertia of the camera and mechanical pan-tilt. It also decreases the optical resolution because of the digital zoom on the interest area. Therefore, we proposed high-speed zooming and tracking optics that consists of an optical zooming unit and an active tracking unit. The two units are designed with coaxial optical paths by a beam splitter. The zooming unit is built with three liquid lenses, one glass lens, and a high-speed camera. It can continuously change the magnification from 1x to 2x. By controlling the optical powers of three liquid lenses, the focal length of the zooming unit can be changed from 40 to 80 mm within milliseconds. The tracking unit composed of a high-speed mirror-based gaze controller, a high-speed camera, and pupil shift optics, can track the object and keep it in the center of both views. In addition, the zooming unit provides a compensation algorithm for the zooming unit to achieve adaptive zoom accurately. The experiment shows that the zooming unit performs adaptive optical zoom, and the tracking unit recognizes the object by adaptive tracking algorithm within 6 milliseconds.
{"title":"Active milliseconds zooming and tracking optics based on liquid lenses and a high-speed gaze controller","authors":"Jiaqi Li, Lin Li, Lihui Wang, Leijin Li, Shaoyong Li","doi":"10.1117/12.2686749","DOIUrl":"https://doi.org/10.1117/12.2686749","url":null,"abstract":"The traditional method of monitoring cameras is employed in robot vision, surveillance cameras, and so on. However, it cannot track as fast as expected due to the large inertia of the camera and mechanical pan-tilt. It also decreases the optical resolution because of the digital zoom on the interest area. Therefore, we proposed high-speed zooming and tracking optics that consists of an optical zooming unit and an active tracking unit. The two units are designed with coaxial optical paths by a beam splitter. The zooming unit is built with three liquid lenses, one glass lens, and a high-speed camera. It can continuously change the magnification from 1x to 2x. By controlling the optical powers of three liquid lenses, the focal length of the zooming unit can be changed from 40 to 80 mm within milliseconds. The tracking unit composed of a high-speed mirror-based gaze controller, a high-speed camera, and pupil shift optics, can track the object and keep it in the center of both views. In addition, the zooming unit provides a compensation algorithm for the zooming unit to achieve adaptive zoom accurately. The experiment shows that the zooming unit performs adaptive optical zoom, and the tracking unit recognizes the object by adaptive tracking algorithm within 6 milliseconds.","PeriodicalId":149506,"journal":{"name":"SPIE/COS Photonics Asia","volume":"23 1","pages":"1276505 - 1276505-9"},"PeriodicalIF":0.0,"publicationDate":"2023-11-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139224731","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}
Ruixi Tang, Xinyu Zheng, Qianqian Zhang, Jiang Wang, Ning Wang, Jie Zhang, Jianjun Chen, Yong Zhu
Fiber optic acoustic sensing system based on Sagnac interference is widely used in the field of perimeter security. However, the sensitivity of acoustic response varies drastically with frequency, which has become a bottleneck limiting the development of Sagnac photoacoustic sensing technology. An elastic structure is proposed to improve the sensitivity consistency of the photoacoustic sensing system based on Sagnac interference at different frequencies. The elastic structure of optical fiber pickup was optimized by finite element analysis, Solidworks and Comsol. Simulation results show that the designed titanium alloy-based elastomeric structure with a diameter of 110 mm, a height of 100 mm, and an elastomer wall thickness of 3 mm has significantly improved the consistency of the sensitivity of the acoustic response at different frequencies. This work provides a possibility for the application scenario expansion of photoacoustic sensing system based on Sagnac interference.
{"title":"A study on the improvement of sensitivity consistency in Sagnac photoacoustic sensing system","authors":"Ruixi Tang, Xinyu Zheng, Qianqian Zhang, Jiang Wang, Ning Wang, Jie Zhang, Jianjun Chen, Yong Zhu","doi":"10.1117/12.2687229","DOIUrl":"https://doi.org/10.1117/12.2687229","url":null,"abstract":"Fiber optic acoustic sensing system based on Sagnac interference is widely used in the field of perimeter security. However, the sensitivity of acoustic response varies drastically with frequency, which has become a bottleneck limiting the development of Sagnac photoacoustic sensing technology. An elastic structure is proposed to improve the sensitivity consistency of the photoacoustic sensing system based on Sagnac interference at different frequencies. The elastic structure of optical fiber pickup was optimized by finite element analysis, Solidworks and Comsol. Simulation results show that the designed titanium alloy-based elastomeric structure with a diameter of 110 mm, a height of 100 mm, and an elastomer wall thickness of 3 mm has significantly improved the consistency of the sensitivity of the acoustic response at different frequencies. This work provides a possibility for the application scenario expansion of photoacoustic sensing system based on Sagnac interference.","PeriodicalId":149506,"journal":{"name":"SPIE/COS Photonics Asia","volume":"10 1","pages":"1277208 - 1277208-8"},"PeriodicalIF":0.0,"publicationDate":"2023-11-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139225259","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}
Huajian Jin, Zijian Lin, Weijie Hao, Y. Ye, Sheng Xu, Qun Yan, Tailiang Guo, Enguo Chen
Micro light-emitting diode (Micro-LED) has the advantages of high brightness, low power consumption, and long life. It has great potential and broad application prospects. Using micro-LED as the light source and image source of the projection system can greatly reduce the size and power consumption of the system. However, the electrical module and the optical module of the micro-LED pico-projection system cannot be separated. This paper uses image fiber to effectively separate the electrical module and optical module in the optical engine, and designs a micro-LED pico-projection optical engine based on an image fiber. This optical engine is composed of a projection lens group, an image fiber and a micro-LED. The projection lens group is composed of 5 spherical lenses, with the total length of 6.752mm and the focal length of 2.8mm. The modulation transfer function (MTF) is higher than 0.8@32lp/mm, and the distortion is below 2%. The image fiber adopts a multi-core fiber with a diameter of 2mm and a resolution of 32lp/mm. Finally, the overall simulation model of the optical engine is built to prove its feasibility.
微型发光二极管（Micro-LED）具有亮度高、功耗低、寿命长等优点。它具有巨大的潜力和广阔的应用前景。使用微型发光二极管作为投影系统的光源和图像源，可以大大减小系统的体积和功耗。然而，微型 LED 微型投影系统的电气模块和光学模块无法分离。本文利用图像光纤将光学引擎中的电气模块和光学模块有效分离，并设计了一种基于图像光纤的微型 LED 微投影光学引擎。该光学引擎由投影透镜组、图像光纤和微型 LED 组成。投影透镜组由 5 个球面透镜组成，总长度为 6.752 毫米，焦距为 2.8 毫米。调制传递函数（MTF）高于 0.8@32lp/mm，失真低于 2%。图像光纤采用多芯光纤，直径为 2mm，分辨率为 32lp/mm。最后，建立了光学引擎的整体仿真模型，以证明其可行性。
{"title":"Design of micro-LED pico-projection optical engine based on an image fiber","authors":"Huajian Jin, Zijian Lin, Weijie Hao, Y. Ye, Sheng Xu, Qun Yan, Tailiang Guo, Enguo Chen","doi":"10.1117/12.2687360","DOIUrl":"https://doi.org/10.1117/12.2687360","url":null,"abstract":"Micro light-emitting diode (Micro-LED) has the advantages of high brightness, low power consumption, and long life. It has great potential and broad application prospects. Using micro-LED as the light source and image source of the projection system can greatly reduce the size and power consumption of the system. However, the electrical module and the optical module of the micro-LED pico-projection system cannot be separated. This paper uses image fiber to effectively separate the electrical module and optical module in the optical engine, and designs a micro-LED pico-projection optical engine based on an image fiber. This optical engine is composed of a projection lens group, an image fiber and a micro-LED. The projection lens group is composed of 5 spherical lenses, with the total length of 6.752mm and the focal length of 2.8mm. The modulation transfer function (MTF) is higher than 0.8@32lp/mm, and the distortion is below 2%. The image fiber adopts a multi-core fiber with a diameter of 2mm and a resolution of 32lp/mm. Finally, the overall simulation model of the optical engine is built to prove its feasibility.","PeriodicalId":149506,"journal":{"name":"SPIE/COS Photonics Asia","volume":"16 1","pages":"127650A - 127650A-6"},"PeriodicalIF":0.0,"publicationDate":"2023-11-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139225456","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}
Sergey N. Mantsevich, E. Kostyleva, Vladimir Khorkin
Generation of dual-combs in frequency shifted feedback laser seeded only with optical amplifier spontaneous emission and containing single frequency shifting loop with single acousto-optic tunable filter as the frequency shifter is demonstrated. It is also shown that it is possible to obtain a pair of dual-combs simultaneously and to implement further down-conversion achieving the frequency spacing between the spectral components of the resulting optical comb equal to the frequency difference of these dual-combs and amounting to several tens of kHz. The OFC with 40 kHz frequency spacing containing more than 5000 spectral lines was observed. It is demonstrated that the generated dual-combs may be applied for optical materials refraction coefficient measurements.
{"title":"Dual optical frequency combs generation with frequency-shifted feedback laser, method, and applications","authors":"Sergey N. Mantsevich, E. Kostyleva, Vladimir Khorkin","doi":"10.1117/12.2687195","DOIUrl":"https://doi.org/10.1117/12.2687195","url":null,"abstract":"Generation of dual-combs in frequency shifted feedback laser seeded only with optical amplifier spontaneous emission and containing single frequency shifting loop with single acousto-optic tunable filter as the frequency shifter is demonstrated. It is also shown that it is possible to obtain a pair of dual-combs simultaneously and to implement further down-conversion achieving the frequency spacing between the spectral components of the resulting optical comb equal to the frequency difference of these dual-combs and amounting to several tens of kHz. The OFC with 40 kHz frequency spacing containing more than 5000 spectral lines was observed. It is demonstrated that the generated dual-combs may be applied for optical materials refraction coefficient measurements.","PeriodicalId":149506,"journal":{"name":"SPIE/COS Photonics Asia","volume":"69 1","pages":"127680R - 127680R-10"},"PeriodicalIF":0.0,"publicationDate":"2023-11-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139232173","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}
A. A. Sovetsky, A. Matveyev, A. A. Zykov, V. Zaitsev, L. Matveev
Computer vision approaches have grown exponentially in recent years. Training AI models often requires annotated data. To increase effectiveness of this procedure one can use semi-automatic semantic annotation tools where some simplified approaches (based either on some pretrained models or visible features parameters) are implemented and manually tuned to isolate specific objects. OCT-signals contain information-bearing specific speckle structure and signal attenuation patterns. The parameters of these patterns corresponds to tangible tissue properties (such as scatterers spatial distributions), therefore can be used to construct semi-automatic semantic annotation tools. Using OCT-signal simulation approaches we evaluate the parameters of speckle patterns and attenuation coefficients and propose novel semantic annotation tools for OCT scans. We demonstrate the performance of semi-automatic 3D segmentation and annotation. This tool can be used as a supportive tool for AI applications as well as independent tool for semi-automatic scans segmentations and further characterization.
近年来，计算机视觉方法呈指数级增长。训练人工智能模型通常需要标注数据。为了提高这一过程的效率，人们可以使用半自动语义注释工具，在这些工具中，一些简化的方法（基于一些预训练模型或可见特征参数）得以实现，并通过手动调整来隔离特定对象。OCT 信号包含特定斑点结构和信号衰减模式的信息。这些模式的参数与有形的组织属性（如散射体空间分布）相对应，因此可用于构建半自动语义注释工具。利用 OCT 信号模拟方法，我们评估了斑点模式和衰减系数的参数，并为 OCT 扫描提出了新的语义注释工具。我们展示了半自动三维分割和注释的性能。该工具既可作为人工智能应用的辅助工具，也可作为半自动扫描分割和进一步表征的独立工具。
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