Spectral characteristics of laser-plasma instabilities with a broadband laser  

作　　者：许国潇 康宁 雷安乐 刘会亚 赵耀 周申蕾 安红海 熊俊 王瑞荣 谢志勇 周熙晨 方智恒 王伟 Guo-Xiao Xu;Ning Kang;An-Le Lei;Hui-Ya Liu;Yao Zhao;Shen-Lei Zhou;Hong-Hai An;Jun Xiong;Rui-Rong Wang;Zhi-Yong Xie;Xi-Chen Zhou;Zhi-Heng Fang;Wei Wang(Key Laboratory of High Power Laser and Physics,Shanghai Institute of Optics and Fine Mechanics,Chinese Academy of Sciences,Shanghai 201800,China;Shanghai Institute of Laser Plasma,China Academy of Engineering Physics,Shanghai 201800,China;School of Science,Shenzhen Campus of Sun Yat-sen University,Shenzhen 518107,China;University of Chinese Academy of Sciences,Beijing 100049,China)

机构地区：[1]Key Laboratory of High Power Laser and Physics,Shanghai Institute of Optics and Fine Mechanics,Chinese Academy of Sciences,Shanghai 201800,China [2]Shanghai Institute of Laser Plasma,China Academy of Engineering Physics,Shanghai 201800,China [3]School of Science,Shenzhen Campus of Sun Yat-sen University,Shenzhen 518107,China [4]University of Chinese Academy of Sciences,Beijing 100049,China

出　　处：《Chinese Physics B》2024年第8期362-368,共7页中国物理B（英文版）

基　　金：Project supported by the National Natural Science Foundation of China (Grant No.11905280)。

摘　　要：Recent experimental progresses regarding broadband laser-plasma instabilities(LPIs)show that a 0.6%laser bandwidth can reduce backscatters of the stimulated Brillouin scattering(SBS)and the stimulated Raman scattering(SRS)at normal incidence[Phys.Rev.Lett.132035102(2024)].In this paper,we present a further discussion of the spectral distributions of the scatters developed by broadband LPIs,in addition to a brief validation of the effectiveness of bandwidth on LPIs mitigation at oblique incidence.SBS backscatter has a small redshift in the broadband case contrary to the blueshift with narrowband laser,which may be explained by the self-cross beam energy transfer between the various frequency components within the bandwidth.SRS backscatter spectrum presents a peak at a longer wavelength in the broadband case compared to the short one in the narrowband case,which is possibly attributed to the mitigation effect of bandwidth on filaments at underdense plasmas.The three-halves harmonic emission(3ω/2)has a one-peak spectral distribution under the broadband condition,which is different from the two-peak distribution under the narrowband condition,and may be related to the spectral mixing of different frequency components within the bandwidth if the main sources of the two are both two-plasmon decays.

关 键 词：laser-plasma instability laser bandwidth light spectrum 

分 类 号：TN24[电子电信—物理电子学] O53[理学—等离子体物理]