根据连续变焦理论模型, 编制连续变焦计算程序, 求得变焦系统初始解, 建立理想光学模型, 通过选材选型及迭代优化, 实现仅由 4片红外透镜及两片平面反射镜组成的中波红外连续变焦光学系统。该系统 F#为 4、工作波段为 3.7～4.8 .m、视场变化范围为 20°×16°～2.0°×1.6°、光学零件最大口径为 71 mm、零件总重 64 g, 系统包络为 172 mm×108 mm, 系统采用两个二元衍射面用于消色差, 通过材料合理配置及主动补偿实现系统消热差设计。该中波红外连续变焦光学系统重量轻、总长短、包络小, 在－40℃～＋60℃温度范围全视场成像质量良好。

According to the theoretical model of continuous zoom optics, the continuous zoom calculation program is compiled, the initial solution of the zoom system is obtained, and the paraxial optical model is established. Through material selection and iterative optimization, a midwave-infrared continuous-zoom optical system consisting of only four infrared lenses and two planar mirrors was realized. The F number of the system is 4, the spectral range is 3.7.to 4.8 .m, the field of view (FOV) is 20°×16°.to.2.0°×1.6°, and the maximum aperture of lenses is 71.0 mm, the total weight of the lenses is 64 g, and the system envelope is 172 mm×108 mm. The system uses two binary surfaces for the achromatic. The athermalization design of the system was realized through the rational allocation of materials and active compensation. The medium wave infrared continuous zoom optical system has the advantages of light weight, short total length, small envelope, and good image quality in the temperature range of -40℃.to 60℃.