{"title":"Hybrid mode-locked wavelength tunable semiconductor laser based on optoelectronic feedback","authors":"Yuxiang Liu, Huan Wang, Zehou Yang, D. Lu, Ruikang Zhang, Lingjuan Zhao","doi":"10.1117/12.2600850","DOIUrl":"https://doi.org/10.1117/12.2600850","url":null,"abstract":"","PeriodicalId":330466,"journal":{"name":"Sixteenth National Conference on Laser Technology and Optoelectronics","volume":"230 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-08-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115899336","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}
Shunhua Wu, Te Li, Dan Wang, Xuecheng Yu, Zhenfu Wang, Guojun Liu
Aiming at the epitaxial structure of the high-power 885nm laser diodes, the factors limiting the further increase of the output power and the power conversion efficiency were investigated. According to the analysis, the epitaxial structure of the laser diodes was optimized, and the influence of the waveguide layer thickness on the carrier absorption loss and the series resistance was theoretically simulated. The results showed that the asymmetric waveguide structure with the thickness ratio of the N-side and the P-side of 6:4 can reduce the carrier absorption loss to the greatest extent. Based on the simulation results, the 885nm laser bars with the optimized epitaxial structure were fabricated and tested under the ambient temperature of 25℃ in a quasi-continuous wave mode of 250μs and 200Hz. The slope efficiency reaches 1.26W/A, while the series resistance is only 1.2mΩ. The power of 277.6W is achieved at 250A injection current and the maximum power conversion efficiency exceeds 64%.
{"title":"Optimization of the epitaxial structure of low-loss 885nm high-power laser diodes","authors":"Shunhua Wu, Te Li, Dan Wang, Xuecheng Yu, Zhenfu Wang, Guojun Liu","doi":"10.1117/12.2602879","DOIUrl":"https://doi.org/10.1117/12.2602879","url":null,"abstract":"Aiming at the epitaxial structure of the high-power 885nm laser diodes, the factors limiting the further increase of the output power and the power conversion efficiency were investigated. According to the analysis, the epitaxial structure of the laser diodes was optimized, and the influence of the waveguide layer thickness on the carrier absorption loss and the series resistance was theoretically simulated. The results showed that the asymmetric waveguide structure with the thickness ratio of the N-side and the P-side of 6:4 can reduce the carrier absorption loss to the greatest extent. Based on the simulation results, the 885nm laser bars with the optimized epitaxial structure were fabricated and tested under the ambient temperature of 25℃ in a quasi-continuous wave mode of 250μs and 200Hz. The slope efficiency reaches 1.26W/A, while the series resistance is only 1.2mΩ. The power of 277.6W is achieved at 250A injection current and the maximum power conversion efficiency exceeds 64%.","PeriodicalId":330466,"journal":{"name":"Sixteenth National Conference on Laser Technology and Optoelectronics","volume":"60 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-08-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121831106","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 key and hot problem in LiDAR is on the development of solid-state LiDAR in intelligent driving field. The disadvantage of solidstate LiDAR technology limits itself in mass production and wider application. A mixed solid-state LiDAR system based on SiPM detecting technology is proposed and realized to be fulfilled as the core guiding, positioning and anti-colliding sensor in intelligent driving vehicle, with wide detecting range, fast refreshing frequency and point density, and wide FOV. Firstly, the background of LiDAR is briefly introduced. Then, A mixed solid-state LiDAR system configured with a 1D MEMS and a motor is designed. After assembly, it has all needed functions and has be tested in indoors and outdoors. The results and data indicated this SiPM technology can be utilized in the mixed-solid state LiDAR to realize wide range, high point density and wide FOV, which can match with the requirement of current intelligent driving system.
{"title":"The development for a mixed static LiDAR system with SiPM detecting technology","authors":"Qiang Gong, Kun Liu, Li Wang","doi":"10.1117/12.2601791","DOIUrl":"https://doi.org/10.1117/12.2601791","url":null,"abstract":"A key and hot problem in LiDAR is on the development of solid-state LiDAR in intelligent driving field. The disadvantage of solidstate LiDAR technology limits itself in mass production and wider application. A mixed solid-state LiDAR system based on SiPM detecting technology is proposed and realized to be fulfilled as the core guiding, positioning and anti-colliding sensor in intelligent driving vehicle, with wide detecting range, fast refreshing frequency and point density, and wide FOV. Firstly, the background of LiDAR is briefly introduced. Then, A mixed solid-state LiDAR system configured with a 1D MEMS and a motor is designed. After assembly, it has all needed functions and has be tested in indoors and outdoors. The results and data indicated this SiPM technology can be utilized in the mixed-solid state LiDAR to realize wide range, high point density and wide FOV, which can match with the requirement of current intelligent driving system.","PeriodicalId":330466,"journal":{"name":"Sixteenth National Conference on Laser Technology and Optoelectronics","volume":"28 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-08-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126400728","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}
Huiyan Jiang, Yuwei Zhu, Zouhua Chen, Xiongjun Cao, Xianlin Song
{"title":"Optimal design of bifocal acoustic lens for large volumetric photoacoustic detection using ZEMAX","authors":"Huiyan Jiang, Yuwei Zhu, Zouhua Chen, Xiongjun Cao, Xianlin Song","doi":"10.1117/12.2603841","DOIUrl":"https://doi.org/10.1117/12.2603841","url":null,"abstract":"","PeriodicalId":330466,"journal":{"name":"Sixteenth National Conference on Laser Technology and Optoelectronics","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-08-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114895936","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 recent years, for the development or application of vortex beams and spatial structured optical fields, the detection of orbital angular momentum (OAM) of vortex beams has become an important topic. In this paper, based on the holographic diffraction grating method of the spatial light modulator (SLM), through a designed diffraction grating whose intensity distribution and diffraction angle are adjustable, the OAM of the single-mode vortex beam is detected. We first started with a self-designed 1D holographic diffraction grating, verified our ideas, and then designed a 2D holographic diffraction grating and successfully detected the OAM of the single-mode vortex beam. The theory and experiment are in great agreement. Our method is useful for the design of SLM-based holographic diffraction gratings and has reference value for OAM detection and data transmission systems based on vortex beams.
{"title":"Orbital angular momentum detection of vortex beam based on diffraction grating","authors":"Yankun Wang, L. Bai, Jinyu Xie, Yazhong Guo","doi":"10.1117/12.2601810","DOIUrl":"https://doi.org/10.1117/12.2601810","url":null,"abstract":"In recent years, for the development or application of vortex beams and spatial structured optical fields, the detection of orbital angular momentum (OAM) of vortex beams has become an important topic. In this paper, based on the holographic diffraction grating method of the spatial light modulator (SLM), through a designed diffraction grating whose intensity distribution and diffraction angle are adjustable, the OAM of the single-mode vortex beam is detected. We first started with a self-designed 1D holographic diffraction grating, verified our ideas, and then designed a 2D holographic diffraction grating and successfully detected the OAM of the single-mode vortex beam. The theory and experiment are in great agreement. Our method is useful for the design of SLM-based holographic diffraction gratings and has reference value for OAM detection and data transmission systems based on vortex beams.","PeriodicalId":330466,"journal":{"name":"Sixteenth National Conference on Laser Technology and Optoelectronics","volume":"5 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-08-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132238476","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}
{"title":"Virtual platform of photoacoustic tomography based on K-Wave","authors":"Qianxiang Wan, Zihao Li, Hongyu Zhang, Shangkun Hou, Hao Zhou, Xianlin Song","doi":"10.1117/12.2603840","DOIUrl":"https://doi.org/10.1117/12.2603840","url":null,"abstract":"","PeriodicalId":330466,"journal":{"name":"Sixteenth National Conference on Laser Technology and Optoelectronics","volume":"46 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-08-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134305188","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 spaceborne LIDAR with laser precision tracking technology was used for a Rendezvous and Docking Mission. In the ground experiment, the laser echo energy attenuation, beam jitter, spot drift, intensity fluctuation, beam expansion and other changes are caused by the effects of atmospheric attenuation and atmospheric turbulence on the light path, and the tracking performance of the lidar has significantly deteriorated compared with the actual application in vacuum environment. In this paper, the atmospheric turbulence effect noise model of laser band of the LIDAR is calculated and simulated. Experiments are carried out in atmospheric turbulence and vacuum environment respectively, and the tracking measurement performance of lidar in non-vacuum with atmospheric turbulence and vacuum environment was verified. The variation of tracking performance of lidar in space and ground is analyzed and some results are also discussed in this paper.
{"title":"Influence of atmospheric turbulence on tracking performance of LIDAR and validation of vacuum experiment","authors":"Shiliang Guo, Wenping Zhang","doi":"10.1117/12.2603075","DOIUrl":"https://doi.org/10.1117/12.2603075","url":null,"abstract":"A spaceborne LIDAR with laser precision tracking technology was used for a Rendezvous and Docking Mission. In the ground experiment, the laser echo energy attenuation, beam jitter, spot drift, intensity fluctuation, beam expansion and other changes are caused by the effects of atmospheric attenuation and atmospheric turbulence on the light path, and the tracking performance of the lidar has significantly deteriorated compared with the actual application in vacuum environment. In this paper, the atmospheric turbulence effect noise model of laser band of the LIDAR is calculated and simulated. Experiments are carried out in atmospheric turbulence and vacuum environment respectively, and the tracking measurement performance of lidar in non-vacuum with atmospheric turbulence and vacuum environment was verified. The variation of tracking performance of lidar in space and ground is analyzed and some results are also discussed in this paper.","PeriodicalId":330466,"journal":{"name":"Sixteenth National Conference on Laser Technology and Optoelectronics","volume":" 3","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-08-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"113948292","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}
Baijie Xu, Jun He, Xizhen Xu, Jia He, Zi-Ping Chen, Yiping Wang
We propose and demonstrate a fiber Bragg grating (FBG) array inscribed with femtosecond laser point-by-point (PbP) method for quasi-distributed high-temperature sensing. Via optimization of grating length, femtosecond laser energy and grating pitch, a wavelength-division-multiplexed (WDM) FBG array including nine FBGs with various Bragg wavelengths ranging from 1510 nm to 1590 nm and an identical ultra-weak FBG array including 60 FBGs with a peak reflectivity of ~0.1‰ were fabricated. After annealing at 700°C for nearly 200 hours, the FBG exhibited a an extremely low Bragg wavelength shift (i.e., -2 pm/h). In addition, the modulation of WDM FBG array was studied. A generalized calibration curve was applied to the FBG array and the maximum fitting error of 27 pm and the temperature measurement accuracy of ± 1.8°C were achieved. And then, the fabricated WDM FBG array was used to realize the quasi-distributed high-temperature sensing up to 700°C in the static and dynamic environment. Such WDM FBG array could be developed for quasi-distributed high-temperature sensing in metallurgical, chemical, and aviation industries.
{"title":"Femtosecond-laser-inscribed Fiber Bragg grating array for quasi-distributed high-temperature sensing","authors":"Baijie Xu, Jun He, Xizhen Xu, Jia He, Zi-Ping Chen, Yiping Wang","doi":"10.1117/12.2603067","DOIUrl":"https://doi.org/10.1117/12.2603067","url":null,"abstract":"We propose and demonstrate a fiber Bragg grating (FBG) array inscribed with femtosecond laser point-by-point (PbP) method for quasi-distributed high-temperature sensing. Via optimization of grating length, femtosecond laser energy and grating pitch, a wavelength-division-multiplexed (WDM) FBG array including nine FBGs with various Bragg wavelengths ranging from 1510 nm to 1590 nm and an identical ultra-weak FBG array including 60 FBGs with a peak reflectivity of ~0.1‰ were fabricated. After annealing at 700°C for nearly 200 hours, the FBG exhibited a an extremely low Bragg wavelength shift (i.e., -2 pm/h). In addition, the modulation of WDM FBG array was studied. A generalized calibration curve was applied to the FBG array and the maximum fitting error of 27 pm and the temperature measurement accuracy of ± 1.8°C were achieved. And then, the fabricated WDM FBG array was used to realize the quasi-distributed high-temperature sensing up to 700°C in the static and dynamic environment. Such WDM FBG array could be developed for quasi-distributed high-temperature sensing in metallurgical, chemical, and aviation industries.","PeriodicalId":330466,"journal":{"name":"Sixteenth National Conference on Laser Technology and Optoelectronics","volume":"194 6","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-08-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114051634","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 machining stability and electrode feeding rate in the shaped tube electrochemical machining (STEM) process was limited by the formation of central residual. Laser-STEM combined the advantages of STEM and water-guided laser machining to enhance the materials removal rate (MRR) and precision, to some extent. In this study, a retracted hybrid tubular electrode was applied to make the MRR between the different machining regions homoplasy. Simulation results showed that the electric current density distribution homogeneity could be improved with the inner low-refractive layer retracted, and got an increase of 38% with a retracted length deg of 2 mm. W-shaped residual in the central machining area could be removed. When the retracted length deg increased from 0 mm to 2 mm, the laser coupling efficiency exceeded 74.5%. Hence, the retracted hybrid tubular electrode could act as both the tool electrode and optical waveguide in the Laser-STEM process. Experiment results confirm the simulation results and showed a significant improvement in machining efficiency and precision by utilizing the retracted hybrid tubular electrode. With the retracted length deg rising from 0 mm to 1.5 mm, the residual height showed a reduction of 72.6% in the STEM process. In the Laser-STEM process, the residual height decreased by 53.8% and 111% with the laser power of 6 W and 10 W, respectively.
{"title":"Influence of hybrid laser and shaped tube electrochemical machining by using retracted electrode","authors":"Y. Yong, Yufeng Wang, Wenwu Zhang","doi":"10.1117/12.2601878","DOIUrl":"https://doi.org/10.1117/12.2601878","url":null,"abstract":"The machining stability and electrode feeding rate in the shaped tube electrochemical machining (STEM) process was limited by the formation of central residual. Laser-STEM combined the advantages of STEM and water-guided laser machining to enhance the materials removal rate (MRR) and precision, to some extent. In this study, a retracted hybrid tubular electrode was applied to make the MRR between the different machining regions homoplasy. Simulation results showed that the electric current density distribution homogeneity could be improved with the inner low-refractive layer retracted, and got an increase of 38% with a retracted length deg of 2 mm. W-shaped residual in the central machining area could be removed. When the retracted length deg increased from 0 mm to 2 mm, the laser coupling efficiency exceeded 74.5%. Hence, the retracted hybrid tubular electrode could act as both the tool electrode and optical waveguide in the Laser-STEM process. Experiment results confirm the simulation results and showed a significant improvement in machining efficiency and precision by utilizing the retracted hybrid tubular electrode. With the retracted length deg rising from 0 mm to 1.5 mm, the residual height showed a reduction of 72.6% in the STEM process. In the Laser-STEM process, the residual height decreased by 53.8% and 111% with the laser power of 6 W and 10 W, respectively.","PeriodicalId":330466,"journal":{"name":"Sixteenth National Conference on Laser Technology and Optoelectronics","volume":"86 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-08-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123843084","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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