A far-infrared (FIR) image contains important invisible information for various applications such as night vision and fire detection, while a visible image includes colors and textures in a scene. We present a coaxial visible and FIR camera system accompanied to obtain the complementary information of both images simultaneously. The proposed camera system is composed of three parts: a visible camera, a FIR camera, and a beam-splitter made from silicon. The FIR radiation from the scene is reflect