本文采用了光机热集成分析的方法对透射式红外光学系统在温度变化条件下进行分析。首先，利用 Zemax建立了 F.为 1和 F.为 2的两个光学系统，利用有限元软件 Patran & Nastran对两个光学系统加载温度场进行热弹性分析，得到镜面节点变形前和变形后的位移。其次，使用 Sigfit将分析得到数据进行 Zernike多项式拟合，得到镜面的 Zernike系数和刚体位移。最后，再将其导入到光学软件 Zemax中，分别考虑镜片面型变化、刚体位移变化和镜片折射率变化 3种因素对其 MTF值的影响。以 F.为 1的光学系统作为主要分析对象，其结果表明在设计要求 65℃（－45℃～20℃）温差下，面型变化使 MTF（17 lp/mm）值下降了 9.72%；刚体位移变化使 MTF值下降了 29.16%；折射率变化使 MTF值下降到 0点，已不再满足光学系统的成像质量要求。其结果表明，折射率变化才是影响红外光学系统成像质量的最主要因素。通过减少温度范围并进行光机热集成分析，得到 F.为 1的光学系统下温差范围为 8℃～32℃，F.为 2的光学系统下温差范围为 6℃～34℃。在两个光学系统的温差范围下 MTF值均大于 0.2，综合考虑建模精度及软件计算精度，其温度最适范围为 13℃～27℃。

In this paper, the optomechanical thermal integration analysis method is used to analyze the transmissive infrared optical system under temperature variation conditions. First, two optical systems—F#1 and F#2—were established by Zemax. The finite element software Patran & Nastran was used to perform thermoelastic analysis on the loading temperature fields of the two optical systems to obtain the displacement of the mirror nodes before and after deformation. Secondly, using Sigfit, the data obtained from the analysis is fitted to the Zernike polynomial to obtain the Zernike coefficient and the rigid body displacement of the mirror. Finally, it is introduced into the optical software Zemax, which considers the influence of lens surface change, rigid body displacement change, and lens refractive index change on its MTF value. The optical system with F# is the main analysis object. The results demonstrate that the surface shape changes the MTF (17 lp/mm) value by 9.72% when the design requires a 65℃ (.45℃–20℃) temperature difference; the displacement of the rigid body reduces the MTF value by 29.16%; the change in refractive index causes the MTF value to drop to zero, which no longer meets the imaging requirements of the optical system. The results show that refractive index change is the most important factor affecting the imaging quality of infrared optical systems. By reducing the temperature difference range and performing optomechanical thermal integration analysis, the temperature difference for the optical system with F# 1 is 8℃ to 32℃, and the temperature difference for the optical system with F# 2 is 6℃ to 34℃. The MTF values are greater than 0.2 in the temperature range of the two opticalsystems. Considering the modeling accuracy and software calculation accuracy, the optimum temperature range is 13℃–27℃.