针对双波段成像系统可以有效提升红外相机的目标探测与识别能力, 选择了折反射式双波段系统结构形成, 提出共孔径分光路中波红外和长波红外双波段成像光学系统。2个谱段共用卡塞格林主光学系统, 采用分色片实现双谱段分光。分光后2个谱段采用相互独立的中继透镜组, 通过二次成像, 实现双波段冷光阑100%匹配。2个谱段焦距均为800 mm, 工作谱段为3.7 μm～4.8 μm和7.7 μm～10.3 μm, 中波和长波的F数分别为2.3和2.8, 视场角为1.2°, 该光学系统各谱段在各自乃奎斯特频率处调制传递函数接近衍射极限, 可满足实际使用需求。

Dual-band/dual-channel imaging system can effectively improve the detection and identification capability for infrared camera. A dual-band catadioptric optical system was designed, in which the mid-wave band and long-wave band could image at the same time. The Cassegrain optics system is shared by two channels, the dichroic lens and independent relay lens are adopted, and by combining with the secondary imaging technology, 100% cold stop efficiency could be realized. The focal length for two channels is 800mm and the wavelengths are 3.7 μm～4.8 μm and 7.7 μm～10.3 μm, respectively,the relative aperture is 1/2.3 for mid-wave band and 1/2.8 for long-wave band with the field of view of 1.2°. The modulation transfer functions of each band at respective fields are all near the diffractive limit, which satisfies the needs of practical applications.