设计了适用于制冷型640×512 中波红外凝视焦平面阵列探测器和1920×1080 的CCD 的可见光/中波红外共口径光学系统。该系统在中波3.6～4.8 μm，可见光0.45～0.9 μm，环境温度－40℃～60℃工作，可见光系统焦距500mm，视场角为0.38°×0.43°，F/#为4；中波红外系统焦距600mm，视场角为0.38°×0.43°，F/#为4.8，满足100%冷光阑效率。本设计利用共用卡塞格林系统，利用分光镜实现可见光与中波红外光谱分光，之后接各自校正像差的镜组。该系统满足工程光学的要求，能够良好成像，双波段系统在－40℃～60℃环境温度下的也能够正常工作，并能够实现可见/中波红外远距离识别。

A set of common aperture optical system with dual bands is presented for 640×512 MWIR and 1920×1080 CCD. The system works in the wavelength ranges of 3.6-4.8 μm and 0.45-0.9 μm and in the environment temperature range of －40℃-60℃. The TV system has an effective focal length of 500 mm, field of view of 0.38°×0.43°, and an F/#of 4; the IR system has a focal length of 600 mm, the field of view of 0.38°×0.43°, an F/#of 4.8, and a cold shield efficiency of 100%. The system takes advantage of Cassegrain system. The beam splitting of the IR/VR is achieved by using a spectroscope and the aberrations are reduced by using respective correcting lenses. The system obtains good image quality for temperatures lying between －40℃-60℃, and can recognize the long-distance targets.