DESIGN, SIMULATION AND FABRICATION OF OPTICAL FILTERS FOR NARROW BAND IMAGING IN ENDOSCOPIC CAPSULES

Abstract — This paper presents the design, simu-lation and fabrication of two optical filters that could be integrated in endoscopic capsules (EC) to perform narrow band imaging (NBI) analysis. The thin-film optical filters were designed for two specific spectral regions (blue, centered at 415 nm, and green, cen-tered at 540 nm) and will be placed on top of current EC white light emitting diodes (LEDs). The filters are composed by 7 thin-film layers of titanium dioxide (TiO2) and silicon dioxide (SiO2) and will be deposited using RF-sputtering technique. The inte-gration of NBI functions in EC represents an im-portant clinical and technological advance, since it will improve the EC diagnostic functions, e.g. en-hanced visibility of capillaries and veins for the diagnosis of dysplasia, as a complement to the cur-rent capsule vision based in white light