惯性约束聚变驱动器终端束匀滑器件前置时频率转换系统优化研究  

Optimization of frequency conversion system in inertial confinement fusion driver for frontally located beam smoothing elements

作　　者：姚欣[1] 高福华[1] 高博[1] 张怡霄[1] 黄利新[1] 郭永康[1] 林祥棣[1] 

机构地区：[1]四川大学物理科学与技术学院,成都610064

出　　处：《物理学报》2009年第7期4598-4604,共7页Acta Physica Sinica

基　　金：国家高技术研究发展计划(863)项目(批准号:804)资助的课题~~

摘　　要：在惯性约束聚变驱动器终端光学系统中,束匀滑器件前置有许多优点,但它同时也将对频率转换系统的工作状态产生影响.从系统集成优化的观点研究了这种影响,并基于高强度激光非线性传输理论,采用耦合波方程组及微扰理论,模拟计算了连续相位板前置时基频光束通过频率转换系统的三倍频转换效率及出射光束的近远场分布和焦斑形态,提出了优化倍频晶体失谐角和晶体厚度以减小CPP前置对系统性能的影响.模拟计算了频率转换系统优化前后的三倍频转换效率、光束通量对比度和能量集中度,并进行了对比分析.分析结果表明,频率转换系统的优化对减小CPP前置对光束质量和三倍频转换效率的影响是十分有效的.There are many advantages for frontally located beam smoothing elements in terminal optical system of the inertial confinement fusion （ICF） driver, but it will also exert an influence on the working state of the frequency conversion system at the same time. This paper studies the influence from the viewpoints of system integration and optimization. Based on the non-linear transmission theory of high power laser and adopting coupled-wave differential equations and perturbation theory, we calculate the third harmonic conversion efficiency, optical characteristics in near and far field as well as the shape of focal spot when CPP is laid before the frequency conversion system. Then we put forward the method for the optimization of detuning angle and thickness of the frequency conversion crystal, in order to reduce influence on ICF system when CPP is laid before the frequency conversion system. The third harmonic conversion efficiency, contrast ratio and encircled energy before and after optimization are compared and analyzed. The results show that the optimization of frequency conversion system is very effective in reducing the impact on the beam quality and the third harmonic conversion efficiency when CPP is laid before the frequency conversion system.

关 键 词：惯性约束聚变 频率转换系统 连续相位板 系统集成优化 

分 类 号：TL632[核科学技术—核技术及应用]