考虑红外多波段双视场共光路系统多谱段色差严重且能量透过率低, 本文设计了结构简单的红外中波/长波双波段双视场折射系统, 实现了成像系统的功能多样性。该系统采用了320 pixel×240 pixel红外中波和长波双色焦平面阵列探测器, 通过引入非球面元件提高了系统校正像差的能力, 实现了镜片组的结构性调整。系统包括变焦和二次成像两个子系统, 其中变焦系统短焦距为50 mm, 长焦距为200 mm, 满足100%冷阑匹配。像质评价结果表明: 在17 lp/mm处, 调制传递函数(MTF)在中波处大于0.5, 在长波处两个视场下都接近衍射极限; 另外80%左右的能量都能被集中在一个像元上, 光谱透过率均匀, 且无严重的冷反射现象。优化后的光学系统具有适用范围广, 结构紧凑以及成像效果好等优点, 在机载光电侦察跟踪设备上有较好的应用前景。

In consideration of the serious chromatic aberration and lower energy transmittance of a multi-band infrared MWIR/LWIR(Medium Wave Infrared/Long Wave Infrared) dual-FOV(Field of View) common-path optical system, a dual-FOV and dual-band common-path refraction optical system is designed to implement the multi functions of the imaging system. The system is based on a cold 320 pixel×240 pixel MWIR/LWIR dual-band staring focal plane array detector and introduces aspherical optical components to improve its aberration correction ability to adjust the align structure of lenses. The optical system is made up of a zoom subsystem and a secondary imaging subsystem with a 50 mm focal length and a 200 mm focal length and satisfies 100% cold shield efficiency. The image evolution shows that the Modulation Transfer Function(MTF)of LWIR and MWIR is almost reaching the limit of diffraction and greater than 0.5 respectively at the spatial frequency of 17 lp/mm, and almost 80% of the energy is concentrated at one pixel. In addition, there is no obvious cold reflect phenomena observed, and the optical system has a preferable application foreground in military and civilian opto-electronic detective fields for its wide scopes of application, compact structure, small volume and good imaging.