Design and fabrication of an integrated multi-channel optical filter working in visible and near-infrared bands

Multi-channel optical filter can separate the target light so that it can be integrated in the multi-spectral imaging system for collecting the images in different spectrum. However, conventional multi-channel optical filter cannot work in visible band and near-infrared band simultaneously. This paper will present a novel method for fabricating the multi-channel filter which can work for the two bands. The method combines pigment-based colorant photoresist microlithography with traditional multi-film vacuum deposition technologies so that the filter has a high integrated level. The results of test show that the filter can be used for the wavelength range from 400 to 1200 urn. Because of its wide working wavelength range, this optical filter has a great prospect of being applied in the fields of day and night surveillance, medical imaging, and so on.