高功率准分子激光主振荡功率放大系统光学元件的稳定性

为了分析高功率准分子激光主振荡功率放大（MOPA）系统中各光学元件稳定性对靶面光斑定位精度的影响，建立了分析模型，利用分析结果指导高稳定性镜架设计以满足系统实验需求。根据高功率准分子激光MOPA系统特点，有效地简化了系统光路，建立了系统光路模型；按照系统打靶精度要求，利用三维坐标变换和光线追迹法，计算得到了系统单个光学元件稳定性对靶面光斑定位精度的影响规律；最后，对自行设计的镜架进行了稳定性测量。计算结果表明，反射镜的旋转变化和透镜垂直光轴的平移变化是影响靶面光斑定位精度的主要因素，且主放大光路中反射镜在x方向和Y方向上最大的变化范围分别不能超过0．8和1．6μrad。实际测量结果表明，设计的镜架在石方向和Y方向最大的变化范围分别为0．6和0．81μrad，满足系统实验要求。

Optical element stability of high power excimer laser MOPA system

In order to analyze the impacts of stability of optical elements on the target positioning in a high power excimer laser Master Oscillator Power Amplification(MOPA) system, an analyzing model for the system was established and a mirror mount was also designed according to the analyzing results to meet the need for the system experiment. Firstly, in light of the unique feature of high power excimer laser MOPA system, the beam path was effectively simplified, and a three dimensional layout model to analyze the system was established. Then, in terms of the model and the requirements of target positioning precision of the system, the stability request of every optical element in this system was obtained by using the three dimensional coordinate conversion and ray-tracing. Finally, the stability parameters of the mirror mount designed by ourselves were measured. The simulating results indicate that the rotations of mirrors and the drift of lens vertical to the optical axis are the chief factors affecting the target positioning precision. In addition, the rotations of mirrors in the main amplifiers round X and Y axes should be controlled less than 0.8 and 1.6 μrad, respectively. The experimental results for the mirror mount designed point out that the rotations round X and Y axes are not more than 0.6 and 0.81 μrad, respectively, which means that the tolerance of coordinate parameters of each optical element corresponding to the target positioning precision satisfies the requirement of the system.