Pub Date : 2021-11-15DOI: 10.11884/HPLPB202133.210246
Yang Xuemei, T. Kan, He Linzhen, Wang Weizhe, Liang Houkun
Mid-infrared (MIR) lasers have various advantages and can be widely used in either fundamental research fields or practical applications such as strong-field physics, molecular sensing and minimally-invasive tissue ablation. Generally, there are two categories of methods to generate MIR laser emission: one is direct lasing and the other is nonlinear frequency down-conversion. However, for the ultra-broadband few-cycle MIR generation, nonlinear down-conversion is the only available method. Intra-pulse Difference Frequency Generation (IP-DFG) is a simple method of nonlinear frequency conversion. In this article, the IP-DFG technology for the ultra-broadband MIR few-cycle pulses generation is reviewed. Different MIR nonlinear crystals, various driving laser sources, the spectral coverage of the MIR-IPDF output, and the conversion efficiency are compared and discussed. Last but not least, the prospects and challenges of MIR IP-DFG are presented.
{"title":"Progress on intra-pulse difference frequency generation in femtosecond laser","authors":"Yang Xuemei, T. Kan, He Linzhen, Wang Weizhe, Liang Houkun","doi":"10.11884/HPLPB202133.210246","DOIUrl":"https://doi.org/10.11884/HPLPB202133.210246","url":null,"abstract":"Mid-infrared (MIR) lasers have various advantages and can be widely used in either fundamental research fields or practical applications such as strong-field physics, molecular sensing and minimally-invasive tissue ablation. Generally, there are two categories of methods to generate MIR laser emission: one is direct lasing and the other is nonlinear frequency down-conversion. However, for the ultra-broadband few-cycle MIR generation, nonlinear down-conversion is the only available method. Intra-pulse Difference Frequency Generation (IP-DFG) is a simple method of nonlinear frequency conversion. In this article, the IP-DFG technology for the ultra-broadband MIR few-cycle pulses generation is reviewed. Different MIR nonlinear crystals, various driving laser sources, the spectral coverage of the MIR-IPDF output, and the conversion efficiency are compared and discussed. Last but not least, the prospects and challenges of MIR IP-DFG are presented.","PeriodicalId":39871,"journal":{"name":"强激光与粒子束","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2021-11-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42173915","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-11-15DOI: 10.11884/HPLPB202133.210308
He Yang, Chen Fei, Wang Haohua, Jia Yanhui
To achieve high-power mid-infrared laser output with high efficiency, the optical parametric oscillator (OPO) based on MgO:PPLN crystal is researched. The pump source is linearly polarized Yb-doped fiber laser (YDFL) with master oscillator power amplifier (MOPA) structure. Experimental results indicate that the YDFL can realize the pulse linearly polarized laser with the highest power of 79.1 W at 1064.1 nm. With the pump laser, the OPO obtains the maximum MIR power of 9.15 W at 3.754 µm by optimizing the curvature radius of output coupler and the pump waist diameter. The corresponding optical-to-optical conversion efficiency is 11.57%. The repetition rate and the pulse width of mid-infrared laser are 300 kHz and ～110 ns, respectively.
{"title":"Fiber-laser-pumped high-power mid-infrared optical parametric oscillator based on MgO:PPLN crystal","authors":"He Yang, Chen Fei, Wang Haohua, Jia Yanhui","doi":"10.11884/HPLPB202133.210308","DOIUrl":"https://doi.org/10.11884/HPLPB202133.210308","url":null,"abstract":"To achieve high-power mid-infrared laser output with high efficiency, the optical parametric oscillator (OPO) based on MgO:PPLN crystal is researched. The pump source is linearly polarized Yb-doped fiber laser (YDFL) with master oscillator power amplifier (MOPA) structure. Experimental results indicate that the YDFL can realize the pulse linearly polarized laser with the highest power of 79.1 W at 1064.1 nm. With the pump laser, the OPO obtains the maximum MIR power of 9.15 W at 3.754 µm by optimizing the curvature radius of output coupler and the pump waist diameter. The corresponding optical-to-optical conversion efficiency is 11.57%. The repetition rate and the pulse width of mid-infrared laser are 300 kHz and ～110 ns, respectively.","PeriodicalId":39871,"journal":{"name":"强激光与粒子束","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2021-11-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47123444","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-09-15DOI: 10.11884/HPLPB202133.210186
Cao Xiangchun, Hao Jian-hong, Zhao Qiang, Zhang Fang, Fan Jieqing, Dong Zhi-wei
The large path loss limits the transmission distance of terahertz wireless communication in the atmosphere. To realize long-range transmission of terahertz waves between the ground and the satellite, the first and key step is to find low attenuation atmospheric transparent windows. In this paper, based on the characteristics of atmospheric distribution in China, atmospheric model (am) is used to compute and compare atmospheric absorption attenuation of terahertz waves in two representative cities, and obtain the most ideal ground-based site suitable for terahertz communication between the ground and the satellite in China. Subsequently, by means of real atmospheric data and layered transmission theory, the total path loss of terahertz communication between the ground and the satellite is calculated. Combined with the signal transmit power, antenna gain, Signal-to-Noise Ratio (SNR), noise power and the corresponding path loss threshold, the total usable bandwidth and atmospheric windows in the 10−15 THz frequency band are given. Moreover, by taking the High Altitude Platform as the terahertz communication relay link between the ground and the satellite, the usable atmospheric windows in the 1−15 THz frequency band with antenna gain of 0−100 dBi are given, which provide theoretical and numerical reference for the establishment of ground-satellite communication links and the selection of ground-based sites and communication frequency bands in China.
{"title":"Analysis of high-frequency atmospheric windows for terahertz communication between the ground and the satellite","authors":"Cao Xiangchun, Hao Jian-hong, Zhao Qiang, Zhang Fang, Fan Jieqing, Dong Zhi-wei","doi":"10.11884/HPLPB202133.210186","DOIUrl":"https://doi.org/10.11884/HPLPB202133.210186","url":null,"abstract":"The large path loss limits the transmission distance of terahertz wireless communication in the atmosphere. To realize long-range transmission of terahertz waves between the ground and the satellite, the first and key step is to find low attenuation atmospheric transparent windows. In this paper, based on the characteristics of atmospheric distribution in China, atmospheric model (am) is used to compute and compare atmospheric absorption attenuation of terahertz waves in two representative cities, and obtain the most ideal ground-based site suitable for terahertz communication between the ground and the satellite in China. Subsequently, by means of real atmospheric data and layered transmission theory, the total path loss of terahertz communication between the ground and the satellite is calculated. Combined with the signal transmit power, antenna gain, Signal-to-Noise Ratio (SNR), noise power and the corresponding path loss threshold, the total usable bandwidth and atmospheric windows in the 10−15 THz frequency band are given. Moreover, by taking the High Altitude Platform as the terahertz communication relay link between the ground and the satellite, the usable atmospheric windows in the 1−15 THz frequency band with antenna gain of 0−100 dBi are given, which provide theoretical and numerical reference for the establishment of ground-satellite communication links and the selection of ground-based sites and communication frequency bands in China.","PeriodicalId":39871,"journal":{"name":"强激光与粒子束","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2021-09-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47046089","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-09-15DOI: 10.11884/HPLPB202133.210330
Cui Bo, Zhang Zhi-meng, Dai Zenghai, Qiyong Wei, Deng Zhi-gang, H. Hua, He Shu-kai, Wang Wei-Wu, Teng Jian, Z. Bo, Liu Hong-jie, Chen Jiabin, Xia Yunqing, Wu Di, M. Wenjun, Hong Wei, Su Jingqin, Zhou Wei-min, Gu Yu-Qiu
The short-pulse neutron source based on ultra-short and ultra-intense laser is an ideal neutron source for ultra-fast neutron detection. For many applications of the novel laser neutron source, the neutron yield now becomes a major limitation. It is proposed here that, based on the Target Normal Sheath Acceleration mechanism (TNSA) and the beam-target reaction scheme, the adoption of composite component target LiD as the neutron converter can be an effective path to enhance the neutron yield. Compared with the traditional LiF converter, which has two typical reaction channels p-Li and d-Li, the use of LiD converter has the advantages on introducing two more reactions channels, i.e., p-D and d-D. Therefore, more reaction channels are expected to be beneficial for increasing the neutron yield. It is experimentally demonstrated that by using LiD converter, an enhancement of 2−3 folds of neutron yield is achieved compared with the LiF converter. As a result, a neutron beam with the highest yield of 5.2×108 sr−1 with a forward beamed distribution is well obtained. The contribution of multi reaction channels is also identified, indicating the enhancement of neutron yield mainly comes from the p-D reaction.
{"title":"Experimental study of high yield neutron source based on multi reaction channels","authors":"Cui Bo, Zhang Zhi-meng, Dai Zenghai, Qiyong Wei, Deng Zhi-gang, H. Hua, He Shu-kai, Wang Wei-Wu, Teng Jian, Z. Bo, Liu Hong-jie, Chen Jiabin, Xia Yunqing, Wu Di, M. Wenjun, Hong Wei, Su Jingqin, Zhou Wei-min, Gu Yu-Qiu","doi":"10.11884/HPLPB202133.210330","DOIUrl":"https://doi.org/10.11884/HPLPB202133.210330","url":null,"abstract":"The short-pulse neutron source based on ultra-short and ultra-intense laser is an ideal neutron source for ultra-fast neutron detection. For many applications of the novel laser neutron source, the neutron yield now becomes a major limitation. It is proposed here that, based on the Target Normal Sheath Acceleration mechanism (TNSA) and the beam-target reaction scheme, the adoption of composite component target LiD as the neutron converter can be an effective path to enhance the neutron yield. Compared with the traditional LiF converter, which has two typical reaction channels p-Li and d-Li, the use of LiD converter has the advantages on introducing two more reactions channels, i.e., p-D and d-D. Therefore, more reaction channels are expected to be beneficial for increasing the neutron yield. It is experimentally demonstrated that by using LiD converter, an enhancement of 2−3 folds of neutron yield is achieved compared with the LiF converter. As a result, a neutron beam with the highest yield of 5.2×108 sr−1 with a forward beamed distribution is well obtained. The contribution of multi reaction channels is also identified, indicating the enhancement of neutron yield mainly comes from the p-D reaction.","PeriodicalId":39871,"journal":{"name":"强激光与粒子束","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2021-09-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45281121","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-09-15DOI: 10.11884/HPLPB202133.210199
Wan Jinyu, Sun Zheng, Zhang Xiang, Bai Yu, Tsai Chengying, Chu Paul, Huang Sen-Lin, Jiao Yi, Leng Yongbin, Li Biaobin, Li Jing-Yi, Li Nan, Lu Xiaohan, Meng Cai, Peng Yuemei, Wang Sheng, Z. Chengyi
Rapid growth of machine learning techniques has arisen over last decades, which results in wide applications of machine learning for solving various complex problems in science and engineering. In the last decade, machine learning and big data techniques have been widely applied to the domain of particle accelerators and a growing number of results have been reported. Several particle accelerator laboratories around the world have been starting to explore the potential of machine learning the processing the massive data of accelerators and to tried to solve complex practical problems in accelerators with the aids of machine learning. Nevertheless, current exploration of machine learning application in accelerators is still in a preliminary stage. The effectiveness and limitations of different machine learning algorithms in solving different accelerator problems have not been thoroughly investigated, which limits the further applications of machine learning in actual accelerators. Therefore, it is necessary to review and summarize the developments of machine learning so far in the accelerator field. This paper mainly reviews the successful applications of machine learning in large accelerator facilities, covering the research areas of accelerator technology, beam physics, and accelerator performance optimization, and discusses the future developments and possible applications of machine learning in the accelerator field.
{"title":"Machine learning applications in large particle accelerator facilities: review and prospects","authors":"Wan Jinyu, Sun Zheng, Zhang Xiang, Bai Yu, Tsai Chengying, Chu Paul, Huang Sen-Lin, Jiao Yi, Leng Yongbin, Li Biaobin, Li Jing-Yi, Li Nan, Lu Xiaohan, Meng Cai, Peng Yuemei, Wang Sheng, Z. Chengyi","doi":"10.11884/HPLPB202133.210199","DOIUrl":"https://doi.org/10.11884/HPLPB202133.210199","url":null,"abstract":"Rapid growth of machine learning techniques has arisen over last decades, which results in wide applications of machine learning for solving various complex problems in science and engineering. In the last decade, machine learning and big data techniques have been widely applied to the domain of particle accelerators and a growing number of results have been reported. Several particle accelerator laboratories around the world have been starting to explore the potential of machine learning the processing the massive data of accelerators and to tried to solve complex practical problems in accelerators with the aids of machine learning. Nevertheless, current exploration of machine learning application in accelerators is still in a preliminary stage. The effectiveness and limitations of different machine learning algorithms in solving different accelerator problems have not been thoroughly investigated, which limits the further applications of machine learning in actual accelerators. Therefore, it is necessary to review and summarize the developments of machine learning so far in the accelerator field. This paper mainly reviews the successful applications of machine learning in large accelerator facilities, covering the research areas of accelerator technology, beam physics, and accelerator performance optimization, and discusses the future developments and possible applications of machine learning in the accelerator field.","PeriodicalId":39871,"journal":{"name":"强激光与粒子束","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2021-09-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42136219","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-08-20DOI: 10.11884/HPLPB202133.210075
Yang Xu, Geng Chao, Liang Xiaoyang, Li Feng, Jiang Jiali, Li Bincheng, Li Xinyang
Beam scanning technology based on optical phased arrays has great potential for applications in the fields of LIDAR, space optical communication, and optical switching. Among them, the microlens array optical phased array can modulate the tilted phase of multiple beams simultaneously through the relative displacement of micrometer scale between microlens arrays, so as to achieve large angle beam scanning, with the advantages of large emitting aperture, simple structure, small size, micro-inertia, etc. Several well-known institutions at home and abroad have conducted research on the microlens array optical phased array. This paper first introduces the scanning principle of microlens array optical phased array, then elaborates on its development status and application, and finally gives an outlook on the trend of its development.
{"title":"Review of microlens array optical phased array beam scanning technique","authors":"Yang Xu, Geng Chao, Liang Xiaoyang, Li Feng, Jiang Jiali, Li Bincheng, Li Xinyang","doi":"10.11884/HPLPB202133.210075","DOIUrl":"https://doi.org/10.11884/HPLPB202133.210075","url":null,"abstract":"Beam scanning technology based on optical phased arrays has great potential for applications in the fields of LIDAR, space optical communication, and optical switching. Among them, the microlens array optical phased array can modulate the tilted phase of multiple beams simultaneously through the relative displacement of micrometer scale between microlens arrays, so as to achieve large angle beam scanning, with the advantages of large emitting aperture, simple structure, small size, micro-inertia, etc. Several well-known institutions at home and abroad have conducted research on the microlens array optical phased array. This paper first introduces the scanning principle of microlens array optical phased array, then elaborates on its development status and application, and finally gives an outlook on the trend of its development.","PeriodicalId":39871,"journal":{"name":"强激光与粒子束","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2021-08-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46522648","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-08-15DOI: 10.11884/HPLPB202133.210236
Sun Liangwei, Luo Qing
The interferometric measurement of the transverse beam size based on synchrotron radiation is a non-intercepting high precision measurement method. Compared with the imaging method, the interferometric method can measure smaller beam size and get better resolution. It is expected to obtain submicron resolution at shorter measurement wavelength, so it is widely used in synchrotron radiation sources. The upgraded scheme of current interference device in Hefei Light Source HLS-II is presented in this paper. It is proposed to replace the first focusing lens in the original interference light path with an RC structure focusing mirror, and the second single lens with a doublet lens. The design goal of this paper is to reduce dispersion and geometric aberration without changing the optical axis of the optical path, so as to improve the imaging quality of the optical path. The geometrical optical path design is used to evaluate the imaging quality of the optical path, and physical optical simulation is performed to obtain the interference fringes of the measurement system. The simulation results show that the radius of Airy spot is reduced by about 35%, the root mean square radius of dot array is reduced by about 99%, the wavefront difference is reduced by about 75%, and the cutoff frequency of MTF function is increased by about 65%, using a focusing mirror to replace the original focusing lens can greatly improve the image quality of the optical path.
{"title":"Design and simulation of interferometer for synchrotron radiation beam size measurement","authors":"Sun Liangwei, Luo Qing","doi":"10.11884/HPLPB202133.210236","DOIUrl":"https://doi.org/10.11884/HPLPB202133.210236","url":null,"abstract":"The interferometric measurement of the transverse beam size based on synchrotron radiation is a non-intercepting high precision measurement method. Compared with the imaging method, the interferometric method can measure smaller beam size and get better resolution. It is expected to obtain submicron resolution at shorter measurement wavelength, so it is widely used in synchrotron radiation sources. The upgraded scheme of current interference device in Hefei Light Source HLS-II is presented in this paper. It is proposed to replace the first focusing lens in the original interference light path with an RC structure focusing mirror, and the second single lens with a doublet lens. The design goal of this paper is to reduce dispersion and geometric aberration without changing the optical axis of the optical path, so as to improve the imaging quality of the optical path. The geometrical optical path design is used to evaluate the imaging quality of the optical path, and physical optical simulation is performed to obtain the interference fringes of the measurement system. The simulation results show that the radius of Airy spot is reduced by about 35%, the root mean square radius of dot array is reduced by about 99%, the wavefront difference is reduced by about 75%, and the cutoff frequency of MTF function is increased by about 65%, using a focusing mirror to replace the original focusing lens can greatly improve the image quality of the optical path.","PeriodicalId":39871,"journal":{"name":"强激光与粒子束","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2021-08-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45016022","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-08-15DOI: 10.11884/HPLPB202133.210158
Liang Ziqiang, Li Xinyang, Gao Zeyu, Jia Qiwang
Wavefront sensing is an important part of adaptive optics system, which plays a key role in the fields of ground-based telescopes, laser transmission in atmosphere, wireless optical communication, laser nuclear fusion, and freeform surface optical measurement etc. Meanwhile, as a general advanced technology, deep learning has made revolutionary progress in many fields such as computer vision, natural language processing and so on. Using deep learning method to improve the wavefront sensor in adaptive optics system to achieve more accurate wavefront detection and adapt to more complex application scenarios is the development trend of adaptive optics, and also a new topic in the field of deep learning. This paper, introduces the application status of deep learning in adaptive optics wavefront sensing in detail. It also analyzes the research characteristics of different types of wavefront sensors, such as phase retrieval wavefront sensor and Shack-Hartmann wavefront sensor, and makes a summary at the end.
{"title":"Review of wavefront sensing technology in adaptive optics based on deep learning","authors":"Liang Ziqiang, Li Xinyang, Gao Zeyu, Jia Qiwang","doi":"10.11884/HPLPB202133.210158","DOIUrl":"https://doi.org/10.11884/HPLPB202133.210158","url":null,"abstract":"Wavefront sensing is an important part of adaptive optics system, which plays a key role in the fields of ground-based telescopes, laser transmission in atmosphere, wireless optical communication, laser nuclear fusion, and freeform surface optical measurement etc. Meanwhile, as a general advanced technology, deep learning has made revolutionary progress in many fields such as computer vision, natural language processing and so on. Using deep learning method to improve the wavefront sensor in adaptive optics system to achieve more accurate wavefront detection and adapt to more complex application scenarios is the development trend of adaptive optics, and also a new topic in the field of deep learning. This paper, introduces the application status of deep learning in adaptive optics wavefront sensing in detail. It also analyzes the research characteristics of different types of wavefront sensors, such as phase retrieval wavefront sensor and Shack-Hartmann wavefront sensor, and makes a summary at the end.","PeriodicalId":39871,"journal":{"name":"强激光与粒子束","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2021-08-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47715666","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-08-15DOI: 10.11884/HPLPB202133.210040
Shi Zongjia, Xiang Zhenjiao, Du Yinglei, Wan Min, gu jing-liang, Li Guohui, Xiang Rujian, You Jiang, Wu Jing, Xu Honglai
Detecting wavefront phase information is the key to realize adaptive optics wavefront compensation. Using convolutional neural network (CNN) instead of wavefront sensor for wavefront reconstruction, the system can be simple and easy to implement, and the reconstruction process is fast and real-time without iteration. To extract the wavefront features from the far field accurately, CNN needs to use a large number of samples for training in advance. In the study, according to the corresponding relationship between Zernike aberration coefficient of orders 4 to 30 and its far-field intensity, the sample data set was simulated, CNN was trained to predict the Zernike aberration coefficient of the distorted wavefront from an input far-field image, then reconstruct the original wavefront. The experimental results show that this method can restore the phase information of wavefront quickly and in real time. Compared with the original wavefront, the reconstructed wavefront has higher wavefront coincidence and smaller residual. It is expected to realize the closed-loop correction in practical adaptive optics systems.
{"title":"Wavefront reconstruction method based on far-field information and convolutional neural network","authors":"Shi Zongjia, Xiang Zhenjiao, Du Yinglei, Wan Min, gu jing-liang, Li Guohui, Xiang Rujian, You Jiang, Wu Jing, Xu Honglai","doi":"10.11884/HPLPB202133.210040","DOIUrl":"https://doi.org/10.11884/HPLPB202133.210040","url":null,"abstract":"Detecting wavefront phase information is the key to realize adaptive optics wavefront compensation. Using convolutional neural network (CNN) instead of wavefront sensor for wavefront reconstruction, the system can be simple and easy to implement, and the reconstruction process is fast and real-time without iteration. To extract the wavefront features from the far field accurately, CNN needs to use a large number of samples for training in advance. In the study, according to the corresponding relationship between Zernike aberration coefficient of orders 4 to 30 and its far-field intensity, the sample data set was simulated, CNN was trained to predict the Zernike aberration coefficient of the distorted wavefront from an input far-field image, then reconstruct the original wavefront. The experimental results show that this method can restore the phase information of wavefront quickly and in real time. Compared with the original wavefront, the reconstructed wavefront has higher wavefront coincidence and smaller residual. It is expected to realize the closed-loop correction in practical adaptive optics systems.","PeriodicalId":39871,"journal":{"name":"强激光与粒子束","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2021-08-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41845275","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-08-15DOI: 10.11884/HPLPB202133.210295
Zhang Zhiguang, Yang Huizhen, Liu Jinlong, Li Songheng, S. Hang, Luo Yuxiang, Wei Xiewen
In recent years, Adaptive Optics (AO) system is developing towards miniaturization and low cost. Because of its simple structure and wide application range, wavefront sensorless (WFSless) AO system has become a research hotspot in related fields. Under the condition that the hardware environment is determined, the system control algorithm determines the correction effect and convergence speed of WFSless AO system. The emerging deep learning and artificial neural network have injected new vitality into the control algorithms of WFSless AO system, and further promoted the theoretical and practical development of WFSless AO. On the basis of summarizing the previous control algorithms of WFSless AO system, the applications of convolution neural network (CNN), long-term memory neural network (LSTM) and deep reinforcement learning in WFSless AO system control in recent years are comprehensively introduced, and characteristics of various deep learning models in WFSless AO system are summarized. Applications of WFSless AO system in astronomical observation, microscopy, ophthalmoscopy, laser telecommunication and other fields are outlined.
{"title":"Research progress in deep learning based WFSless adaptive optics system","authors":"Zhang Zhiguang, Yang Huizhen, Liu Jinlong, Li Songheng, S. Hang, Luo Yuxiang, Wei Xiewen","doi":"10.11884/HPLPB202133.210295","DOIUrl":"https://doi.org/10.11884/HPLPB202133.210295","url":null,"abstract":"In recent years, Adaptive Optics (AO) system is developing towards miniaturization and low cost. Because of its simple structure and wide application range, wavefront sensorless (WFSless) AO system has become a research hotspot in related fields. Under the condition that the hardware environment is determined, the system control algorithm determines the correction effect and convergence speed of WFSless AO system. The emerging deep learning and artificial neural network have injected new vitality into the control algorithms of WFSless AO system, and further promoted the theoretical and practical development of WFSless AO. On the basis of summarizing the previous control algorithms of WFSless AO system, the applications of convolution neural network (CNN), long-term memory neural network (LSTM) and deep reinforcement learning in WFSless AO system control in recent years are comprehensively introduced, and characteristics of various deep learning models in WFSless AO system are summarized. Applications of WFSless AO system in astronomical observation, microscopy, ophthalmoscopy, laser telecommunication and other fields are outlined.","PeriodicalId":39871,"journal":{"name":"强激光与粒子束","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2021-08-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46304800","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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