CMOS Compatible Hyperspectral Optical Filters

摘要

Commonly, optical filters consist of pigments on glass or of many stapled interference layers. In bothrncases, they are not applied on CMOS devices within the fab line, as they are not CMOS-compatible.rnConsequently, further processing is needed and high additional costs are incurred. It is presented arnmethod for producing tuneable optical filters with tuneable transmission spectra in a CMOS-line.Thernfilters are constituted by a Fabry-Perot resonator formed by two Bragg mirrors separated by arnpatterned cavity. The filter response can be tuned by changing the geometric parameters of thernpatterning, and consequently the cavity effective refractive index. In this way, many different filters canrnbe produced at once on a single chip, allowing multichanneling. The filter has been designed,rnproduced, and characterized. The results for a chip with 24 filters are presented.