提出一种超紧凑型折反式红外光学系统设计方法，即系统的主、次镜均采用金属镜，后组采用红外透射材料，实现了总长/焦距比为0.55。在设计中重点分析系统的温度效应，并采取针对性设计，以达到准无热化设计的目的。同时对系统进行杂光分析，给出杂光抑制方案，并使用杂光分析软件对系统进行分析。结果表明：系统像面杂散辐射在0.5%以内，光学材料与结构材料的热胀系数配合得当，系统的热效应很好。

The design method of a compact infrared catadioptric system is proposed. In the design, the metal mirrors are adopted for the primary and secondary mirrors in the system, and the IR transmission material is used for the rear set of lenses. The ratio of total length and focus length is 0.55. The temperature effects of the system were analyzed during the design process and an effective measure was taken for the purpose of making the system quasi-athermalized. The parasitic light in the system was also analyzed. A scheme to suppress the parasitic light is given. The analysis result shows that the stray light on the image plane of the system is less than 0.5%, the expansion coefficients of optical material and structural material are proper for their match, and the thermal effect of the system is verified.