摘要
激光驱动惯性约束聚变的打靶过程中,光场不同空间频率的不均匀性会引起内爆的流体力学不稳定性、印痕效应和激光等离子体不稳定性。这些不稳定过程将最终影响内爆压缩倍率,从而影响到点火。为了控制焦斑不均匀性进而抑制不稳定过程,人们提出了束匀滑技术:通过光场调控控制焦斑分布特性,进而控制束靶耦合过程。束匀滑可分为空间域匀滑和时间域匀滑。空间域匀滑通过控制波前形态获得平整的焦斑包络,降低低频不均匀性。时间域匀滑通过控制光束的相干性减弱激光焦斑中的散斑,进而减弱中高频不均匀性。随着抑制更高激光功率密度条件下激光等离子体相互作用的需求愈发紧迫,涌现出一些新型的束匀滑方法。文中介绍了束匀滑技术在大型激光装置上的使用情况,并对目前提出的各种束匀滑技术进行了总结和分析。
In the process of laser driven inertial confinement fusion,the inhomogeneity of light field with different spatial frequencies will cause the hydrodynamic instability,imprinting and laser plasma instability in implosion.These instabilities will eventually affect the compression ratio of implosion,thus affecting the ignition.In order to control the focal spot nonuniformity and suppress instabilities,beam smoothing technology was proposed to control the beam target coupling process through light field control.Beam smoothing can be divided into spatial smoothing and temporal smoothing.Spatial smoothing can reduce the low-frequency inhomogeneity by controlling the wavefront shape.Temporal smoothing reduces the speckle in the focal spot by controlling the coherence of the laser beam,and then reduces the medium and high frequency inhomogeneity.With the increasing demand for laser-plasmas instability suppression at higher laser power density,some new beam smoothing methods have emerged.The application of beam smoothing technology in large laser facilities was introduced,and the currently proposed beam smoothing technologies were summarized and analyzed.
作者
高妍琦
李福建
季来林
赵晓晖
夏兰
冯伟
刘栋
史海涛
刘佳妮
饶大幸
崔勇
马伟新
隋展
Gao Yanqi;Li Fujian;Ji Lailin;Zhao Xiaohui;Xia Lan;Feng Wei;Liu Dong;Shi Haitao;Liu Jiani;Rao Daxing;Cui Yong;Ma Weixin;Sui Zhan(Shanghai Institute of Laser Plasms,China Academy of Engineering Physics,Shanghai 201800)
出处
《红外与激光工程》
EI
CSCD
北大核心
2020年第12期74-87,共14页
Infrared and Laser Engineering
基金
科学挑战计划(TZ2016005)
国家自然科学基金(11604317,11604318,11804321)。
关键词
高功率激光驱动器
光束匀滑
诱导空间非相干
谱色散匀滑
偏振匀滑
连续相位板
透镜阵列
high power laser driver
beam smoothing
induced spatial incoherence
smoothing by spectrum dispersion
polarization smoothing
continuous phase plate
lens array
