MULTISPECTRAL INTERFERENCE FILTERS AND THEIR APPLICATION TO THE DESIGN OF COMPACT NONDISPERSIVE INFRARED GAS ANALYZERS FOR POLLUTION-CONTROL

The integration process of different thin-film interference filters on a unique substrate to give multispectral filter arrays has been studi ed. Filter arrays properly combined with detector arrays would permit the obtention of multispectral integrated sensors or retinas with spat ial and spectral resolution, possibly in the focal plane of a staring sensor. In this work experimental results related to the planar integr ation of different multilayers onto the same substrate are described. Special attention is devoted to the study of the stability of multilay er properties and their relation to the development and photolithograp hic process parameters. The application of infrared filter arrays to t he development of compact non-dispersive infrared sensors with no movi ng parts for gas analysers is also discussed.