为了减小激光辐照下反射镜镜面的热变形问题，建立了反射镜热变形的有限元分析模型。对不同制冷功率时的镜面热变形进行分析，然后针对吸收功率为50 W、光斑半径为镜体半径1/3时的TEM00模高斯光束对镜体结构进行优化，对优化后的反射镜在不同参数的TEM00模高斯光束和TEM10、TEM11模厄米特-高斯光束辐照下的热变形进行了分析。仿真结果表明，当施加滞后于激光辐照且与吸收功率近似大小的制冷时，有利于减小镜面热变形，且镜体最终会趋于相对稳定的热平衡状态。此外，当镜体背部切去一厚度为1.4 mm、内径为25 mm 的环状区域时，热变形峰谷（PV）值仅为0.005 μm；同时，优化后的镜体也可在一定程度上减小其他参数激光辐照下的镜面热变形的PV 值。对于TEM00模高斯光束和TEM10、TEM11模厄米特-高斯光束，均满足光学系统对热变形的要求。

In order to reduce the thermal-deformation of the silicon mirror, a finite element method analysis system about the thermal-deformation of the mirror is established. The thermal-deformation of the mirror with different semiconductor refrigeration powers are compared, then, for the TEM00 mode Gaussian beam whose radius is 1/3 of the mirror, the structure of the mirror is optimized when the absorbed power is 50 W. The optimized mirror in the TEM00 mode Gaussian beam of different parameters and TEM10, TEM11 mode Hermite-Gaussian beam under the irradiation of the thermal deformation are analyzed. The simulation results show that when the semiconductor refrigeration power equals the power of the laser absorbed and lags behind the laser works, the deformation is largely improved and is relatively stable at last. In addition, when a circular area with thickness of 1.4 mm and inner radius of 25 mm is removed at the backside of the mirror, the peak valley (PV) value is 0.005 mm. The PV value of the thermal distortion of the optimized mirror is reduced in a certain extent under other laser radiations. For TEM00 mode Gaussian beam and TEM10, TEM11 mode Hermite-Gaussian beam, the mirror satisfies the requirement of the optic system.