Compact dual band/dual FOV infrared imaging system with freeform prism

For higher detection capability, dual band/dual field of view (FOV) infrared imaging systems are often used to recognize camouflaged targets. In this Letter, we report a dual band/dual FOV infrared imaging system with freeform prism, in which the optical path is folded drastically. Each spectral band will pass through the same entrance pupil and then is split off by a beam splitter so that each spectral band can match a different FOV. Compared to traditional infrared imaging systems, the proposed system has advantages of less volume, higher integration, and optical efficiency.