C. Xiang, Zhaoyang Ttang, Yuanshen Xiao, Yingchun Ding, Jiaqi He
The research of light focusing and imaging through scattering media is currently a popular topic. Many focusing technologies have been developed, such as transmission matrix method, phase conjugation method, iterative optimization method, etc. However, these methods have some limitations. At present, deep learning methods have been widely used in the field of image restoration, and have strong inverse restoration capabilities. Yet, the application of this method in the field of optical focusing is still relatively limited, and the performance is not ideal. In this letter, a method based on complex neural network is proposed, and the multi-point focusing of light passing through the scattering medium is numerically simulated. Since the complex information of the network is not reduced, compared with the real number neural network method, this method more accurately simulates the recovery process of light scattering, and can obtain multiple light focal points with high enhancement at the same time.
{"title":"Research on multi-point light focusing based on complex neural network","authors":"C. Xiang, Zhaoyang Ttang, Yuanshen Xiao, Yingchun Ding, Jiaqi He","doi":"10.1117/12.2603136","DOIUrl":"https://doi.org/10.1117/12.2603136","url":null,"abstract":"The research of light focusing and imaging through scattering media is currently a popular topic. Many focusing technologies have been developed, such as transmission matrix method, phase conjugation method, iterative optimization method, etc. However, these methods have some limitations. At present, deep learning methods have been widely used in the field of image restoration, and have strong inverse restoration capabilities. Yet, the application of this method in the field of optical focusing is still relatively limited, and the performance is not ideal. In this letter, a method based on complex neural network is proposed, and the multi-point focusing of light passing through the scattering medium is numerically simulated. Since the complex information of the network is not reduced, compared with the real number neural network method, this method more accurately simulates the recovery process of light scattering, and can obtain multiple light focal points with high enhancement at the same time.","PeriodicalId":330466,"journal":{"name":"Sixteenth National Conference on Laser Technology and Optoelectronics","volume":"94 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":"121865881","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}
Li Wang, B. Dong, Jin Yang, Shikun He, Yunli Bai, Gang Wang
5μm thickness silicon coatings were deposited on RB-SiC、S-SiC、Si and Bk7 substrates using ion-assisted e-beam evaporation method, respectively. Renishaw inVia confocal laser Raman spectrometer was used to study the microstructure of all the samples. The measurement results show that the substrate’s thermal expansion coefficient has great influence on the microstructure of nano-silicon coatings. Owing to 300 degree deposition temperature, there will be thermal stress when the samples are cooled down, which leading to medium-range and short-range order of silicon molecular structure change. Accordingly, TA and TO2 mode will appear or disappear in Raman scattering spectra. Amorphous silicon coating can crystalize after laser irradiation with different Raman scattering TO peak offset for different substrates. Especially for nanosilicon coatings grown on reaction bonded SiC (RB-SiC) and Sintered SiC (S-SiC) under the same deposition conditions, they have different Raman scattering spectra and their thermal stress is different, which will give guidance to deposition and polishing process of nano-silicon layers.
{"title":"Raman analysis of the microstructures of nano-silicon coatings grown on different substrates","authors":"Li Wang, B. Dong, Jin Yang, Shikun He, Yunli Bai, Gang Wang","doi":"10.1117/12.2602897","DOIUrl":"https://doi.org/10.1117/12.2602897","url":null,"abstract":"5μm thickness silicon coatings were deposited on RB-SiC、S-SiC、Si and Bk7 substrates using ion-assisted e-beam evaporation method, respectively. Renishaw inVia confocal laser Raman spectrometer was used to study the microstructure of all the samples. The measurement results show that the substrate’s thermal expansion coefficient has great influence on the microstructure of nano-silicon coatings. Owing to 300 degree deposition temperature, there will be thermal stress when the samples are cooled down, which leading to medium-range and short-range order of silicon molecular structure change. Accordingly, TA and TO2 mode will appear or disappear in Raman scattering spectra. Amorphous silicon coating can crystalize after laser irradiation with different Raman scattering TO peak offset for different substrates. Especially for nanosilicon coatings grown on reaction bonded SiC (RB-SiC) and Sintered SiC (S-SiC) under the same deposition conditions, they have different Raman scattering spectra and their thermal stress is different, which will give guidance to deposition and polishing process of nano-silicon layers.","PeriodicalId":330466,"journal":{"name":"Sixteenth National Conference on Laser Technology and Optoelectronics","volume":"41 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":"125099616","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}
Small angle light scattering measurement is more relevant for determining the size of solid aerosols, but small scattering angle measurement results will be interfered by larger stray light. The key technology is to suppress the background noise caused by the Fraunhofer diffraction of the laser light source and the Rayleigh scattering of atmospheric molecules, so as to improve the resolution of weak scattered light signal of strong light absorption small particle aerosol. An adaptive filtering method of forward small angle aerosol scattering signal is proposed based on recursive least-square (RLS) algorithm. By analyzing the characteristics of small-angle aerosol detection signals, the forgetting factor in traditional RLS is optimized, so that it can not only distinguish aerosol scattered light signals from stray light signals, but also dynamically adjust according to the amplitude change under different particle size and absorbance. In order to verify the filtering effect, small angle scattering light pulse extraction experiments of aerosols with different absorbance and different particle sizes were conducted in a simulated smoke box. Experiments show that the proposed variable forgetting factor RLS algorithm can effectively suppress stray light signals caused by laser light sources and atmospheric molecules. When the aerosol detection signal appears, the algorithm has fast convergence speed and tracking speed, which highlights the aerosol pulse signal well. Compared with the traditional method, the resolution of the processed aerosol scattering pulse signal increases dramatically and has a great advantage in the extraction of weak scattering pulse signal.
{"title":"Extraction of forward small angle particle scattering light pulse signal based on variable forgetting factor RLS algorithm","authors":"Rongrui Zhang, Heng Zhao","doi":"10.1117/12.2603148","DOIUrl":"https://doi.org/10.1117/12.2603148","url":null,"abstract":"Small angle light scattering measurement is more relevant for determining the size of solid aerosols, but small scattering angle measurement results will be interfered by larger stray light. The key technology is to suppress the background noise caused by the Fraunhofer diffraction of the laser light source and the Rayleigh scattering of atmospheric molecules, so as to improve the resolution of weak scattered light signal of strong light absorption small particle aerosol. An adaptive filtering method of forward small angle aerosol scattering signal is proposed based on recursive least-square (RLS) algorithm. By analyzing the characteristics of small-angle aerosol detection signals, the forgetting factor in traditional RLS is optimized, so that it can not only distinguish aerosol scattered light signals from stray light signals, but also dynamically adjust according to the amplitude change under different particle size and absorbance. In order to verify the filtering effect, small angle scattering light pulse extraction experiments of aerosols with different absorbance and different particle sizes were conducted in a simulated smoke box. Experiments show that the proposed variable forgetting factor RLS algorithm can effectively suppress stray light signals caused by laser light sources and atmospheric molecules. When the aerosol detection signal appears, the algorithm has fast convergence speed and tracking speed, which highlights the aerosol pulse signal well. Compared with the traditional method, the resolution of the processed aerosol scattering pulse signal increases dramatically and has a great advantage in the extraction of weak scattering pulse signal.","PeriodicalId":330466,"journal":{"name":"Sixteenth National Conference on Laser Technology and Optoelectronics","volume":"8 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":"124982725","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}
Xinyi Li, Zexin Zhang, P. Duan, J. Tian, Yanrong Song
Dark soliton is a promising tool in communication systems for its ability to preserve its good shape. This paper demonstrates the generation of dark soliton in an Yb-doped fiber laser with a compact figure-9 resonator based on the principle of nonlinear amplifying loop mirror. In this laser, when the polarization controller is located in the gain fiber or single-mode fiber, the generation of dark soliton, bright soliton and bright-dark soliton pair, as well as the transformation between them, can be realized. This experiment provides the evidence on the generation of dark soliton at 1 μm, and the results show that the figure-9 fiber laser may obtain dark soliton, bright soliton or bright-dark soliton pair by simply adjusting the PC, which is helpful to obtain dark-soliton pulses in fiber lasers.
{"title":"Experimental investigation on dark solitons formation in Figure-9 Yb doped fiber laser","authors":"Xinyi Li, Zexin Zhang, P. Duan, J. Tian, Yanrong Song","doi":"10.1117/12.2603121","DOIUrl":"https://doi.org/10.1117/12.2603121","url":null,"abstract":"Dark soliton is a promising tool in communication systems for its ability to preserve its good shape. This paper demonstrates the generation of dark soliton in an Yb-doped fiber laser with a compact figure-9 resonator based on the principle of nonlinear amplifying loop mirror. In this laser, when the polarization controller is located in the gain fiber or single-mode fiber, the generation of dark soliton, bright soliton and bright-dark soliton pair, as well as the transformation between them, can be realized. This experiment provides the evidence on the generation of dark soliton at 1 μm, and the results show that the figure-9 fiber laser may obtain dark soliton, bright soliton or bright-dark soliton pair by simply adjusting the PC, which is helpful to obtain dark-soliton pulses in fiber lasers.","PeriodicalId":330466,"journal":{"name":"Sixteenth National Conference on Laser Technology and Optoelectronics","volume":"7 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":"125319880","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}
Ti-6Al-4V (TC4) titanium alloys have been extensively used in aviation due to their good comprehensive mechanical properties. However, TC4 has low hardness and poor wear resistance, which cannot meet the increasingly stringent working environment requirements of aerospace. Thus, it is necessary to enhance their performance by posttreatment. Laser shock peening (LSP) is an advanced surface treatment technology that improve the hardness and fatigue life of the metal material by ultra-high plastic strain. However, laser shock peening has limits to improve the surface hardness of workpiece. And heat treatment can effectively improve the performance of titanium alloys. Therefore, the combination of heat treatment and laser shock peening is used to improve the surface hardness of TC4. In this study, the Ti-6Al-4V (TC4) samples were subjected to one and two LSP impacts, respectively. Heat treatment was performed on the sample that has been subjected to one impact, and one of the heat-treated samples was subjected to one impact again. The surface hardness was measured by a Vickers hardness tester meter. The fracture morphologies were observed by scanning electron microscope (SEM) and phase characterization was measured by X-ray diffractometer (XRD). The effect of laser shock peening and heat treatment on the surface hardness of TC4 samples was experimentally investigated. The results showed that the maximum surface hardness of the treated sample was increased by 56.8% compared with original sample. Therefore, the combination of laser shock peening and heat treatment can greatly increase the surface hardness of the TC4.
{"title":"Effect of laser shock peening and heat‑treated on surface hardness of Ti–6Al–4V","authors":"Liming Yuan, Wentai Ouyang, X. Qin, Wenwu Zhang, Pengkai Liu, Hongyu Quan, Tianrun Zhang","doi":"10.1117/12.2603187","DOIUrl":"https://doi.org/10.1117/12.2603187","url":null,"abstract":"Ti-6Al-4V (TC4) titanium alloys have been extensively used in aviation due to their good comprehensive mechanical properties. However, TC4 has low hardness and poor wear resistance, which cannot meet the increasingly stringent working environment requirements of aerospace. Thus, it is necessary to enhance their performance by posttreatment. Laser shock peening (LSP) is an advanced surface treatment technology that improve the hardness and fatigue life of the metal material by ultra-high plastic strain. However, laser shock peening has limits to improve the surface hardness of workpiece. And heat treatment can effectively improve the performance of titanium alloys. Therefore, the combination of heat treatment and laser shock peening is used to improve the surface hardness of TC4. In this study, the Ti-6Al-4V (TC4) samples were subjected to one and two LSP impacts, respectively. Heat treatment was performed on the sample that has been subjected to one impact, and one of the heat-treated samples was subjected to one impact again. The surface hardness was measured by a Vickers hardness tester meter. The fracture morphologies were observed by scanning electron microscope (SEM) and phase characterization was measured by X-ray diffractometer (XRD). The effect of laser shock peening and heat treatment on the surface hardness of TC4 samples was experimentally investigated. The results showed that the maximum surface hardness of the treated sample was increased by 56.8% compared with original sample. Therefore, the combination of laser shock peening and heat treatment can greatly increase the surface hardness of the TC4.","PeriodicalId":330466,"journal":{"name":"Sixteenth National Conference on Laser Technology and Optoelectronics","volume":"15 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":"116793314","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}
Xiaoyan Yu, Jin Zhang, Yuqing Chen, Mian Huang, X. Dai
{"title":"Imbert-Fedorov shifts in anisotropic two-dimensional atomic crystals","authors":"Xiaoyan Yu, Jin Zhang, Yuqing Chen, Mian Huang, X. Dai","doi":"10.1117/12.2603132","DOIUrl":"https://doi.org/10.1117/12.2603132","url":null,"abstract":"","PeriodicalId":330466,"journal":{"name":"Sixteenth National Conference on Laser Technology and Optoelectronics","volume":"152 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":"114307367","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 laser polishing process of metal materials has been extensively studied. This paper proposes a new type of beam-coupled laser polishing method to study the surface quality of polished stainless steel when the power and frequency change, and the changes of the surface roughness and topography with the laser power and frequency were analyzed. Under the condition of power 0.5W and frequency 10Khz, as the feed speed changes from 200mm/min to 1200mm/min, the surface roughness first decreases, then slightly increases. The single pulse energy decreases, and the surface roughness first increases and then decreases with increasing of the frequency from 10kHz to 20kHz. With low repetition frequency and single pulse energy, the surface roughness is significantly reduced to 0.19μm at the process parameters of 2.0W, 10Khz, and 600mm/min. Under the specific process parameters, the processed surface has a color change similar to that caused by surface quenching treatment. The surface material absorbs more laser light, and the processed surface microstructure changes. By adjusting the process parameters, the polishing quality can be improved. It is proved that the beam-coupled laser polishing of stainless steel is an effective polishing method.
{"title":"Changes in surface characteristics of stainless steel polished by nanosecond laser based on beam coupling","authors":"Xiaoxiao Chen, Yuan Li, Huihui Zhang, Wenwu Zhang","doi":"10.1117/12.2603292","DOIUrl":"https://doi.org/10.1117/12.2603292","url":null,"abstract":"The laser polishing process of metal materials has been extensively studied. This paper proposes a new type of beam-coupled laser polishing method to study the surface quality of polished stainless steel when the power and frequency change, and the changes of the surface roughness and topography with the laser power and frequency were analyzed. Under the condition of power 0.5W and frequency 10Khz, as the feed speed changes from 200mm/min to 1200mm/min, the surface roughness first decreases, then slightly increases. The single pulse energy decreases, and the surface roughness first increases and then decreases with increasing of the frequency from 10kHz to 20kHz. With low repetition frequency and single pulse energy, the surface roughness is significantly reduced to 0.19μm at the process parameters of 2.0W, 10Khz, and 600mm/min. Under the specific process parameters, the processed surface has a color change similar to that caused by surface quenching treatment. The surface material absorbs more laser light, and the processed surface microstructure changes. By adjusting the process parameters, the polishing quality can be improved. It is proved that the beam-coupled laser polishing of stainless steel is an effective polishing method.","PeriodicalId":330466,"journal":{"name":"Sixteenth National Conference on Laser Technology and Optoelectronics","volume":"19 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":"134538252","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}
Terahertz time-domain spectroscopy has been widely applied in performing dielectric analysis for various materials. However, air voids trapped in samples will significantly affect the characterization. In this study, the refractive index of mixture samples consisting of iron trioxide and polytetrafluoroethylene in five different mass ratios were measured with terahertz time-domain spectroscopy. In order to extract the intrinsic refractive index of iron trioxide, the effective medium model of CRI was then applied to remove refractive index of PTFE in the sample. The extracted refractive indices were presented as a variable parameter decrease with the increase of iron trioxide content, which also corresponds to the increase of air voids in the tablets. The correlation between trapped air voids and analyte composition roots from the coarse rust particles used in pellets compression. This study shows that the influence of air porosity should be considered when terahertz waves are utilized to characterize dielectric property of coarse material.
{"title":"The influence of sample porosity on refractive index in THz non-destructive testing","authors":"Ying Li, Zhaohui Zhang, Xiaoyan Zhao, Tian-yao Zhang","doi":"10.1117/12.2602928","DOIUrl":"https://doi.org/10.1117/12.2602928","url":null,"abstract":"Terahertz time-domain spectroscopy has been widely applied in performing dielectric analysis for various materials. However, air voids trapped in samples will significantly affect the characterization. In this study, the refractive index of mixture samples consisting of iron trioxide and polytetrafluoroethylene in five different mass ratios were measured with terahertz time-domain spectroscopy. In order to extract the intrinsic refractive index of iron trioxide, the effective medium model of CRI was then applied to remove refractive index of PTFE in the sample. The extracted refractive indices were presented as a variable parameter decrease with the increase of iron trioxide content, which also corresponds to the increase of air voids in the tablets. The correlation between trapped air voids and analyte composition roots from the coarse rust particles used in pellets compression. This study shows that the influence of air porosity should be considered when terahertz waves are utilized to characterize dielectric property of coarse material.","PeriodicalId":330466,"journal":{"name":"Sixteenth National Conference on Laser Technology and Optoelectronics","volume":"45 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":"127807684","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}
Qiao Shan, Liwen Sheng, Ping Song, Zhang Aiguo, Guo Honglong, Li Peng, Jinpeng Lang, Jin Hui, Qu Tianyang
We propose and experimentally validate a distributed refractive index (RI) sensor obtained by simply bending a piece of standard single mode fiber (SMF) to a radius of curvature in several millimeters with intact buffer coating. The RI of the external medium surrounding the U-bent optical fibers is measured by the wavelength shifts of the local Rayleigh backscattered spectra when the RI ranges from 1.3330 to 1.3773. To demonstrate the ability of distributed RI sensing based on the proposed method, this presented sensing element is employed to measure multipoint RI variations at the same time. The sensitivities are about 19.61nm/RIU (RI units), 27.59nm/RIU and 39.08nm/RIU in the proposed structure, respectively.
{"title":"Measurement of distributed refractive index through Rayleigh backscattering spectra detection using a U-bent common fiber","authors":"Qiao Shan, Liwen Sheng, Ping Song, Zhang Aiguo, Guo Honglong, Li Peng, Jinpeng Lang, Jin Hui, Qu Tianyang","doi":"10.1117/12.2600768","DOIUrl":"https://doi.org/10.1117/12.2600768","url":null,"abstract":"We propose and experimentally validate a distributed refractive index (RI) sensor obtained by simply bending a piece of standard single mode fiber (SMF) to a radius of curvature in several millimeters with intact buffer coating. The RI of the external medium surrounding the U-bent optical fibers is measured by the wavelength shifts of the local Rayleigh backscattered spectra when the RI ranges from 1.3330 to 1.3773. To demonstrate the ability of distributed RI sensing based on the proposed method, this presented sensing element is employed to measure multipoint RI variations at the same time. The sensitivities are about 19.61nm/RIU (RI units), 27.59nm/RIU and 39.08nm/RIU in the proposed structure, respectively.","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":"129541117","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 influence of pulse width on relativistic motion and full spatial characteristics of radiation generated from electron oscillations driven by circularly polarized intense femtosecond laser pulses have been investigated theoretically and numerically using a single electron model. The electron trajectories show asymmetric spiral patterns for few-cycle laser pulse which do not resemble with twofold symmetric spiral patterns in the multi-cycle laser pulse. It is discovered that the patterns of the full spatial distribution of electron emission are of the shape resembling a flower of calla for few-cycle laser pulse and the radiated power per unit solid angle show a horn like shape directed toward the direction of the laser pulses propagation with a narrower divergence for multi-cycle laser pulse.
{"title":"Influence of different pulse width on electron emission characteristics driven by circularly polarized intense laser","authors":"Lingxiao Li, Mengyuan Tao, P. Yu, Youwei Tian","doi":"10.1117/12.2600833","DOIUrl":"https://doi.org/10.1117/12.2600833","url":null,"abstract":"The influence of pulse width on relativistic motion and full spatial characteristics of radiation generated from electron oscillations driven by circularly polarized intense femtosecond laser pulses have been investigated theoretically and numerically using a single electron model. The electron trajectories show asymmetric spiral patterns for few-cycle laser pulse which do not resemble with twofold symmetric spiral patterns in the multi-cycle laser pulse. It is discovered that the patterns of the full spatial distribution of electron emission are of the shape resembling a flower of calla for few-cycle laser pulse and the radiated power per unit solid angle show a horn like shape directed toward the direction of the laser pulses propagation with a narrower divergence for multi-cycle laser pulse.","PeriodicalId":330466,"journal":{"name":"Sixteenth National Conference on Laser Technology and Optoelectronics","volume":"18 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":"123924921","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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