Common-aperture infrared dual-waveband dual-field-of-view optical system

The invention provides a common-aperture infrared dual-waveband dual-field-of-view optical system, and solves the problems of complex structure and large size of an overall imaging system due to the fact that a plurality of independent infrared waveband imaging systems are adopted in existing multi-waveband infrared detection. The system comprises a front fixed group, a zooming group, a rear fixedgroup and a projection lens group, wherein the projection lens group comprises a long-wave projection lens group and a medium-wave projection lens group which can be switched with each other; the front fixed group comprises a meniscus lens with positive focal power bent to the image space and a meniscus lens with negative focal power bent to the image space; the zooming group is a biconcave thirdlens with negative focal power; the rear fixed group comprises a positive-focal-power biconvex lens, a negative-focal-power meniscus lens bent to the object side, a positive-focal-power meniscus lensbent to the image space an