中波和长波红外双波段消热差光学系统设计

为了有效提高目标的红外探测与识别能力,设计了能同时对高温和常温目标成像的中波和长波红外双波段消热差光学系统。所设计的光学系统采用柯克型结构,视场、有效焦距和相对孔径分别为5.5°×4.4°、100 mm和F/2,工作波段覆盖中波红外(波长3～5μm)和长波红外(8～12μm)。通过采用光学被动消热差方法,优化设计的镜头可工作于-60～80℃的环境温度,奈奎斯特频率处的调制传递函数(MTF)值变化小于0.05。该镜头使用Ge、ZnSe和ZnS 3种红外材料,具有后工作距大、100%冷光阑效率等特点。

Design of an athermalized MWIR and LWIR dual-band optical system

In order to effectively improve the target detection and recognition ability of IR imagers,an athermalized MWIR and LWIR dual-band optical system was designed,which can image high temperature and normal temperature objects at the same time.The designed optical system used Cooke structure.Its full field of view,effective focal length,and F number were respectively 5.5°×4.4°,100 mm,and 2.Its work wavelength ranged both middle and long wavelength infrared(MWIR and LWIR,i.e.3-5 μm and 8-12 μm).Through the method of optical passive athermalization,the optimization design of the lens can be suitable for the environmental temperature of-60-80℃,and its MTF value at Nyquist frequency changed less than 0.05.The objective consisted of four lenses made from Ge,ZnSe and ZnS.It has the advantages of large back focal length and 100% cold shield efficiency.