屏蔽罩的优化设计与杂散光分析

Optimized Design and Strayed Light Analysis of Shield

为了解决激光惯性约束聚变系统中屏蔽罩引起的杂散光问题,建立了屏蔽罩的三维蜂窝结构模型,提出了屏蔽罩的杂散光分析方法,分析了屏蔽罩的蜂窝曲率与两蜂窝中心间距对杂散光的影响。结果表明:激光通过屏蔽罩反射,始终存在反射光光强最强区域;不同角度的反射光强度峰谷值和光反射回原光束的总能量随着屏蔽罩蜂窝直径和蜂窝间距的增大而增大。基于此,在设计屏蔽罩时,应严格控制蜂窝直径与蜂窝间距,使终端光学系统避开反射光最强区域,使得散射光相对均匀地分布到立体空间中。

To solve the problem of strayed light introduced by the shield in an inertial confinement fusion system, we establish a three-dimentional honeycomb structural model and propose a strayed light analysis method of shield. We also analyze the influences of the honeycomb curvature and central distance of two honeycombs on the strayed light. The results show that the laser is reflected through the shield, and there is always an area with the highest light intensity of the reflected light. The peak-to-valley of the reflected light intensity and total power of the light back to system increase with the increasing honeycomb diameter and honeycomb spacing of the shield. Based on this, the diameter and spacing of honeycomb should be controlled strictly when we design shield, so that to make the terminal optical system keep away from the area of highest reflected light intensity and let the strayed light distribute evenly in solid space.