项目名称： 基于多光束参量调控的组束匀滑技术研究

项目编号： No.61475145

项目类型： 面上项目

立项/批准年度： 2015

项目学科： 无线电电子学、电信技术

项目作者： 张锐

作者单位： 中国工程物理研究院激光聚变研究中心

项目金额： 80万元

中文摘要： 惯性约束聚变物理实验要求高功率激光装置精确控制靶面光强分布，因而广泛采用了相位板技术以进行焦斑空域整形。由于光束内部子束间的相干性，相位板会在靶面产生散斑结构，从而在打靶时产生各种不利的非线性过程和成丝，影响靶丸对称压缩，因而还需要采用时域匀滑和偏振匀滑等措施。目前已对单束光的时域、空域和偏振匀滑特性进行了研究，但对多束光的组束匀滑特性国内外尚未开展系统研究。而在多达数百束的兆焦耳级激光驱动器中，为满足靶场光束排布需采用组束聚焦，因此亟需对组束匀滑特性进行研究以支撑驱动器设计。本项目将对组束打靶过程中的时域、空域和偏振等多个参量开展创新性调控技术研究，从而掌握组束匀滑的参量优化设计和实现方法。重点要突破的难点包括：多光束组束打靶时子束偏振态、光谱角色散方向等参量对靶面辐照均匀性的影响；新型偏振调控方法的优化设计和实现方法。本项目将为高功率激光装置组束匀滑技术的发展提供理论和技术支撑。

中文关键词： 激光技术；固体激光；高功率激光装置；激光等离子体

英文摘要： In the high-power laser facilities used for inertial confinement fusion (ICF), the physical experiments require well defined laser focal spots. To precisely control the distribution of laser focal spots in spatial domain, various phase plates are developed and widely used. While, phase plates break the beam into a series of beamlets, and the interference between these beamlets will lead to speckles, causing instabilites and filamentation in the laser fusion experiments. Therefore, beam smoothing technologies in time and polarization domain are required to be adopted to suppress the laser-plasma instabilities, and attain symmetry compression of the target capsules. For the moment, several laser beam smoothing technologies have been studied for the single beam circumstance,in time, spatial and polarization domain, such as smoothing by spectral dispersion (SSD), continuous phase plates (CPP) and polarization smoothing (PS). While, for the overlapping focusing properties of multiple beams, systematic research is still scarce. Considering megajoule laser drivers with hundreds of beams, combined beam focusing will be needed to adapt to beam orientation in the target area. Therefore, characteristics of combined beam smoothing are required to be analyzed to support the design of laser drivers. Here, combined beam smoothing using novel parameter manipulation methods in time, spatial and polarization domain will be studied to improve the target illumination uniformity. The research will be focused mainly on the followings: influences of the direction of polarization and angular spectral dispersion on target illumination uniformity of combined laser beams; optimization and realization ways of new polarization smoothing methods. The subject will provide theoretical and experimental support for the development of combined laser beam technology of high-power laser facilities.

英文关键词： laser technology;solid-state laser;high power laser facility;laser-plasma interactions