随着激光功率的不断提升，等离子体光学成为研究热点。而其中基于强耦合布里渊散射激光驱动生成的等离子体光栅作为一种新型的等离子体光学元件受到广泛关注。然而相关的研究却面临着两个关键问题：一是驱动激光之间的能量交换过程，该过程使激光的包络受到调制、局部区域有质动力势非均匀分布，从而严重影响等离子体光栅的性质；二是驱动激光在等离子体中传播时的不稳定性过程，如噪声拉曼散射不稳定性，会消耗驱动激光的能量并对电子进行随机加热，影响光栅的生成。本项目会针对这两个关键问题进行理论研究，获取光栅生成过程中驱动激光之间的能量交换和不稳定性增长的物理规律，提出新的物理方案调控激光能量交换过程以改善光栅空间分布情况、抑制不稳定性的增长保障驱动激光的稳定传输。此外，入射激光在等离子体光栅中的传播特性的研究有利于光栅应用的开发，本项目将针对该问题进行研究，重点分析超短超强脉冲激光在动态光栅中的频率下转换现象。

As the laser power increases continuously, plasma optics becomes a research hotspot. The laser-driven plasma grating based on strongly coupled stimulated Brillouin scattering attracts much attention as a new type of plasma optical element. But the associated research faces two key problems: (1) the energy exchange process between the driving lasers, which modulates the lasers’ envelopes and makes local ponderomotive potential distribute inhomogeneously. It affects the properties of the plasma grating severely. (2) the instabilities during the propagation of driving lasers in plasma. For example, the instability of noise Raman scattering, it consumes the energy of the driving lasers and heat the electrons randomly, which affects the generation of the grating. This project will study these two problems theoretically, to obtain the physical laws of energy exchange between the driving lasers and the instability growth. This project will also propose new physical schemes to control the energy exchange for improving the spatial distribution of the grating, to suppress the growth of the instabilities for the stable propagation of the driving lasers. Moreover, the study on the propagating characteristics of the injected laser in the plasma grating facilitates the development of the grating’s applications. This project will also study this problem, especially the frequency downshift of the ultrashort and ultraintense laser in a dynamic plasma grating.