为了研究强激光输出窗口热行为对光束质量的影响，从Strehl比的普遍公式出发，推导出热变形情况下考虑材料折射率温度效应的Strehl比计算公式和远场强度分布公式。计算并分析了蓝宝石、石英、单晶硅组成的窗口镜的热变形对光束质量的影响。激光功率越高，引起的窗口的热变形越显著，使得Strehl比和远场归一化强度越低，因而光束质量越差；在考虑到材料折射率的温度效应时，在相同的激光辐射条件下，蓝宝石的Strehl比随激光功率的变化较平缓。结果表明，高功率激光器的窗口热变形及其基片材料折射率的温度效应对远场光束质量具有较大的影响。

To investigate the influence of thermal deformation of high-power laser output windows on the beam quality,the Strehl ratio formula and the far-field normalized intensity under thermal aberration were induced with the thermal effect of the refractive index of the materials considered. The influence of the thermal aberration of the output windows on the Strehl ratio and the far-field normalized intensity were analyzed and discussed. The results show that under the same laser radiation,in the presence of temperature effect of refractive index,the far-field Strehl ratio of Al₂O₃ changes the slowest with the laser radiation power among the three materials.