Control and ultra-short pulse generation in stimulated Raman backscattering

8th International Conference on Inertial Fusion Sciences and Applications

Škori, Milo M.^1,2,3 ; Nikoli, Ljubomir^4 ; Hadievski, Ljupo^1 ; Batani, Dimitri^3 ; Ishiguro, Seiji^2 ; Mima, Kunioki^5

Vina Institute of Nuclear Sciences, University of Belgrade, Belgrade

11001, Serbia^1

National Institute for Fusion Science, Graduate University for Advanced Studies, Japan^2

Université Bordeaux, CEA, CNRS, CELIA, Talence

F-33405, France^3

Geomagnetic Laboratory, NRCan, Ottawa

ON

K1A OY3, Canada^4

Institute of Laser Engineering, Osaka University, Japan^5

关键词: Intermittent pulsations;    Nonlinear frequency;    Nonlinear saturation;    Particle simulations;    Pulse generation;    Raman amplification;    Stimulated raman scatterings (SRS);    Ultrashort pulse generation;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/688/1/012112/pdf
DOI  :  10.1088/1742-6596/688/1/012112

来源: IOP

【 摘 要 】

A stimulated Raman scattering (SRS) is a great concern for laser fusion, causing an energy and symmetry loss and target preheating. In particular, for dominating backward- SRS (BRS), a complexity of nonlinear saturation was revealed. Recently, to develop lasers at multi-exawatts and beyond, relevant to high-energy physics, a proposed Raman amplification based on BRS met a restrictive operation window. Here, we stress BRS generics that due to a nonlinear frequency shift (relativistic/trapping effect), it nonlinearly saturates with intermittent pulsations. A "break up" of Manley-Rowe invariants explains a non-steady saturation. Further, a coherent pulsation BRS regime is proposed for femto-sec pulse generation in a thin exploding foil plasma, with parameter scalings investigated by analytics and particle simulations.