大型激光装置光学元件的稳定性分析

大型高功率固体激光装置对打靶精度有很高的要求，总的打靶精度通常在几十微米。而分配到单个光学元件的稳定性指标只有几微米或者几个微弧度，某些光学元件的稳定性指标甚至小于一微弧。这就对结构的稳定性提出了很高的要求。以一大型激光装置为背景，以关键光机系统为例进行稳定性设计。应用有限元理论对关键光学元件及其支撑结构的稳定性进行分析，以验证光机结构设计的合理性。分析结果表明关键光学元件均满足稳定性设计指标和裕度系数。

Stability of optical elements in large laser facilities

Large high-power solid-state laser facilities have a very high requirement for the total positioning error budget(＜50 μm in general), so it is a very important to improve the stability of structure design.In this paper,the stability design is illustrated for several key optical and mechanical systems in the large laser facility. Then,several kinds of methods,such as reinforced concrete supports,truss structures,vibration isolation,integrated design and inhencing structure rigidness are used to reduce the effect of optical and mechanical structures on the ambient vibration and to improve the structure stablility,and finite element models are established to analyse the stablility of the key optical elements and support structures and to verify that the structure design is reasonable or not.The results show that the maximum rotation angles of key optical elements, i.e. cavity mirrors, Injection Mirror (IM), and the mirror in beam switch module are 0.14, 0.423, and 0.394 μrad, respectively,and their design margins are greater than 1.5.These results indicate that the optical elements and support structures can satisfy the design indices for stability.