高功率激光驱动器光束匀滑技术研究（特邀）

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。

Research of beam smoothing technology in high power laser driver (Invited)

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.