为解决CO₂激光器高反膜耦合窗在腔内高功率激光作用下产生的热效应问题，对耦合窗的温度场和热形变场进行了理论分析研究。通过谐振腔工作状态分析，首次提出了腔内振荡激光具有混合模式分布的表达式，并利用半解析热分析方法得出了在混合模式下耦合窗产生的温度场和热形变场的一般表达式，同时与将腔内激光分布作均匀分布、高斯分布假设下耦合窗的情况作了对比分析。研究结果，当腔内谐振功率为3800W、腔内激光混合模式分布时，耦合窗内表面中心最大热形变量约为0．91 μm，作均匀分布、高斯分布假设分别造成最大热形变量偏小20．88%，偏大78．02%。

To solve thermal effect problem of the coupler window with HR coating of CO₂ laser caused by higher power oscillating laser in resonator,the temperature field and thermal deformation field of the coupler window were researched. Through analyzing the work state of resonant cavity,the mathematical expression of the oscillating laser in cavity with a blending mode was first given. The general solutions of temperature field and thermal deformation field of coupler window with the blending oscillating laser were obtained by the semi-analytic thermal analysis method. And the results were compared with the thermal solutions of the coupler window by the oscillating laser with the homogeneous distribution and the Gauss distribution. The results show that when the power of the oscillating laser in cavity is 3800W,the maximum thermal deformation of coupler window with the blending oscillating laser is 0.91 μm,while the maximum thermal deformation by the assumptions of the homogeneous distribution and the Gauss distribution are smaller by 20.88% and larger by 78.02%.