中国物理B ›› 2024, Vol. 33 ›› Issue (8): 85204-085204.doi: 10.1088/1674-1056/ad426d

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Spectral characteristics of laser-plasma instabilities with a broadband laser

Guo-Xiao Xu(许国潇)1,4, Ning Kang(康宁)1,†, An-Le Lei(雷安乐)2,‡, Hui-Ya Liu(刘会亚)1, Yao Zhao(赵耀)3, Shen-Lei Zhou(周申蕾)1, Hong-Hai An(安红海)2, Jun Xiong(熊俊)2, Rui-Rong Wang(王瑞荣)2, Zhi-Yong Xie(谢志勇)2, Xi-Chen Zhou(周熙晨)2, Zhi-Heng Fang(方智恒)2, and Wei Wang(王伟)2   

  1. 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
  • 收稿日期:2024-03-05 修回日期:2024-04-10 出版日期:2024-08-15 发布日期:2024-07-15
  • 通讯作者: Ning Kang, An-Le Lei E-mail:kangning@siom.ac.cn;lal@siom.ac.cn
  • 基金资助:
    Project supported by the National Natural Science Foundation of China (Grant No. 11905280).

Spectral characteristics of laser-plasma instabilities with a broadband laser

Guo-Xiao Xu(许国潇)1,4, Ning Kang(康宁)1,†, An-Le Lei(雷安乐)2,‡, Hui-Ya Liu(刘会亚)1, Yao Zhao(赵耀)3, Shen-Lei Zhou(周申蕾)1, Hong-Hai An(安红海)2, Jun Xiong(熊俊)2, Rui-Rong Wang(王瑞荣)2, Zhi-Yong Xie(谢志勇)2, Xi-Chen Zhou(周熙晨)2, Zhi-Heng Fang(方智恒)2, and Wei Wang(王伟)2   

  1. 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
  • Received:2024-03-05 Revised:2024-04-10 Online:2024-08-15 Published:2024-07-15
  • Contact: Ning Kang, An-Le Lei E-mail:kangning@siom.ac.cn;lal@siom.ac.cn
  • Supported by:
    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. 132 035102 (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 (3$\omega /2$) 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

Abstract: 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. 132 035102 (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 (3$\omega /2$) 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.

Key words: laser-plasma instability, laser bandwidth, light spectrum

中图分类号:  (Laser-plasma interactions)

  • 52.38.-r
52.57.-z (Laser inertial confinement) 52.38.Bv (Rayleigh scattering; stimulated Brillouin and Raman scattering)