Multi-Spectral Low-Light Imaging

"Night-vision systems have significantly enhanced military operations in low-light conditions. These systems have improved greatly since their introduction; their resolution, light sensitivity, and signal-to-noise ratio have increased. However, currentcommercial night-vision systems produce a monochrome image on the intensifier tube screen. While these systems are extremely useful, their performance could be greatly enhanced if the color of objects could be discriminated. We propose a solution toachieve color night vision using existing intensifier technology and monolithic filters to provide color. Multistate color filters are placed in line with an image intensifier tube. The filters have a single aperture that can be switched to pass red,green, blue (RGB) wavelengths. When the wavelength passed by the filters is cycled rapidly through RGB, the human visual system perceives the images as a single, full-color image. The design has several advantages over alternative designs and is a leadingcandidate for a manufacturable, low-cost, color, night-vision system. Our design is solid state, i.e. has no moving parts. The filters are low-power devices that are ideal for portable, battery-operated systems. Also, our design has reduced complexity andsize over multi-tube systems, making it easy to incorporate into existing night vision systems. Relevant applications are present in both military and commercial markets. The proposed device is a