基于衍射光学元件的红外弱目标探测系统设计

根据非制冷焦平面阵列（FPA）探测器性能参数以及所需探测红外弱目标的大小与探测距离，计算并设置了系统参数，设计并研制了与之相匹配的长波红外光学系统，实现了对红外弱目标的探测。该红外光学系统基于6°×6°视场角，采用像方远心光路来实现。分析与计算结果表明，采用衍射非球面设计的由两片Ge镜片组成的红外弱目标探测光学系统具有重量轻、系统能量传输效率高和像质优良的优势。与三片球面Ge-AMTIR1-Ge红外光学系统相比，系统质量轻25%，能量传输效率高7%；与常规非球面Ge-Ge透镜系统相比，像质改善50%。比较结果显示，可见衍射非球面光学元件在红外弱目标探测系统中具有较好的应用前景。

Design of optical system based on diffraction optics for infrared weak target detection

A long wave infrared optical system was designed and developed by setting the system parameters based on the performance of a non-refrigeration focal-plane array(FPA) detector and by calculating the sizes and detection distances of an infrared weak target, and then the target detection for weak signals was realized successfully. This infrared optical system based a field of view in 6°×6° is implemented with the image space centrifugal path. Analysis and calculation results show that the optical system with two pieces of Ge-based diffraction optics has advantages of lower weight, higher energy transmission ability and good image quality. As compared with that of the three-piece spherical surface Ge-AMTIR1-Ge system, the weight of the system has lighted by 25% and the efficiency has improved by 7%. Moreover, the image quality has improved 50% than that of the traditional aspheric surface Ge-Ge method. These results show that the optical system has a wider application future in infrared weak target detection fields.