DEPOSITION OF MULTIPLE INFRARED SPECTRAL FILTERS DIRECTLY ON FOCAL PLANE ARRAY

NASA instruments like the Thermal Infrared Sensor (TIRS) on LANDSAT-8 and -9 feature multiple infrared focal plane arrays (FPAs) integrated with several spectral filters to provide satellite-based push-broom multi-spectral imaging of planet Earth. A key drawback is the use of discrete filters that need special hardware for stabilization (to survive a rocket launch) and precision alignment to within microns of the FPAs, adding weight to an assembly that has to be cooled by a large cryocooler for cryogenic operation. A more elegant solution is to deposit thin-film filters directly on a single large-format FPA, lightening the package, making it more reliable optically, and drastically improving the size, weight, reliability, and mission life of the cryocooler.In Phase I, we propose to develop and demonstrate such a solution, a key challenge being to achieve the demanding passband requirements of such filters. In Phase II, we will develop and deliver a camera featuring a large-format FPA with multiple spectral filters deposited on it that will provide NASA with greater ground resolution in a smaller and lighter package than current multi-spectral sensors in use.