基于光场分布特性分析的高功率激光吸收体设计方法研究

高功率激光装置需要利用激光吸收体实现对杂散光的有效管控。然而吸收体受光面交界处极易发生激光损伤，可能导致激光装置内部的洁净环境受到污染。为了解决这一问题，基于有限元分析方法，模拟了高功率激光吸收体受光面交界处在包括无过渡、圆弧过渡和平面过渡等不同过渡条件下介质内部的光场分布，分析了吸收玻璃界面对光场的影响，得到了介质内部光场峰值强度及峰值位置的变化规律。结果显示:吸收体的损伤可能是由于过渡面为曲面导致的。研究工作为吸收玻璃的激光损伤研究和吸收体设计提供参考。

Designing method research of high-power laser absorber based on analysis of light field distribution characteristics

Laser absorbers are necessary for high power laser facilities to achieve effective control of the stray lights. However, the boundaries of the absorber light receiving surfaces are easily to be damaged by the laser, which may cause the pollution of the clean environment inside the facility. To solve this problem, based on methods of finite element analysis, light field distribution in medium of high-power laser absorber with its boundary of light receiving surface under conditions of no-transition, plan transition and curved surface transition were simulated. Effects of absorption glass boundary on light field were analyzed. Transformation regularity of the intensity and position of light field peak inside the medium were obtained. The results indicate that the damage of the absorber may be caused by the curved surface transition of the boundary. This research provides a reference for research of laser damage and absorber designing.