DEVELOPMENT OF COATINGS FOR IMPROVED IR DETECTOR EFFICIENCY

THE PERFORMANCE OF LONG WAVELENGTH INFRARED DETECTORS COULD BE SIGNIFICANTLY ENHANCED IF IT WAS POSSIBLE TO DEPOSIT ANTI-RELECTIVE (AR) COATINGS DIRECTLY UPON THE SURFACE OF THESE DETECTORS. APPLICATION OF AR COATINGS COULD (1) GREATLY REDUCE REFLECTANCE LOSSES (30-35%) INCURRED AT THE UNCOATED SURFACE OF DETECTORS, (2) REDUCE CROSSTALK IN THE OPTICAL TRAIN, AND (3) INCREASE DETECTIVITY WHICH TRANSLATES INTO REDUCED WEIGHT AND PACKAGING PENALTIES. TO ACHIEVE THIS GOAL, THE DEVELOPMENT OF A DEPOSITION PROCESS FOR COATING IR DETECTORS OF THE PC, PV AND BACKSIDE ILLUMINATOR TYPES WILL BE INVESTIGATED THROUGH THE DESIGN AND DEPOSITION OF AR AND BANDPASS FILTER COATINGS. EVALUATION CRITERIAL WILL INCLUDE: SPECTRAL TRANSPARENCY, DEPOSITION DIFFICULTY, THERMAL AND INSTRINSIC STRESS PROPERTIES AND ENVIRONMENTAL DURABILITY. ANTICIPATED RESULTS AT THE COMPLETION OF PHASE I WILL BE THE DEVELOPMMENT OF SINGLE AND/OR DOUBLE LAYER AR COATING CONFIGURATIONS FOR IR DETECTORS.