Multi-Channel Near-Infrared Bandpass Mosaic Filter for Spectral Fundus Imaging

Abstract

We previously reported a near-infrared (NIR) color fundus camera that can image the fundus without the use of mydriatic agents. Using this technology, pseudo-color images can be reconstructed from images in the three NIR wavelength bands. In this study, we designed and manufactured a five-wavelength bandpass mosaic filter for CMOS image sensors (CIS) by modifying the thickness of the middle layer of a multilayer thin-film structure based on the interference bandpass filter principle. It is possible to acquire information about all bands at all locations on the fundus by using the fixational movement of the human eye. Adapting a fabricated 5-channel CIS, we report the validity of high-spatial-resolution imaging by demosaicing and spectral resolution enhancement by deconvolution processing.