MULTICOLOR SENSORS FOR IMPROVED AIRBORNE INFRARED SEARCH AND TRACKING

A NEED EXISTS FOR AN INFRARED (IR) IMAGING SPECTROMETER THAT MEASURES SIMULTANEOUSLY SPATIAL AS WELL AS SPECTRAL DISTRIBUTIONS OF IR TARGETS, FOR TARGET RECOGNITION AND DISCRIMINATION AGAINST CLUTTER OR DECOYS. RECENT ADVANCES IN SEMICONDUCTOR BANDGAP ENGINEERING BY MOLECULAR BEAM EPITAXY (MBE) HAVE PRODUCED QUANTUMWELL DETECTORS IN THE FORM OF SUPERLATTICES (SLS) WITH VERY NARROW SPECTRAL BANDS IN THE INFRARED. THE SL DETECTORS CAN BE USED TO CONSTRUCT AN IMAGING SPECTROMETER WITH HIGH SPATIAL AND SPECTRAL RESOLUTION THAT CAN MEET THIS NEED. THIS PROPOSAL IS TO DEVELOP A VERTICAL STACK OF THESE SLS, EACH RESPONDING TO AN UNIQUE NARROW BAND, USING THE MBE GROWTH OF SLS OF ALGAAS/GAAS. BY ALTERING THE PERIODICITY OF THE SLS THE INFRARED BANDS WILL BE CHANGED SO THAT THE QUANTUM-WELL DETECTORS FORMING AN IR SPECTROMETER WILL RESPOND TO THE BANDS SIMULTANEOUSLY. AN ARRAY OF THESE SL STACKS WILL BE USED TO FORM THE FINAL IMAGING SPECTROMETER EITHER IN THE STARING OR SCANNING MODE. SPECIAL EFFUSION SOURCES, MBE EPITAXIAL GROWTH PROCESSES AND FEW TRAIL EPITAXY GROWTH RUNS WILL BE DESIGNED, DELINEATED AND MADE, RESPECTIVELY, IN PHASE I FOR THE SPECTROMETER DEVELOPMENT. PHASE II WILL BE DEVOTED TO THE FABRICATION OF THE SL SPECTROMETER, WHILE PHASE III WILL BE DEDICATED TO CONSTRUCTING THE IMAGING SPECTROMETER, SPECIFICALLY FOR AIRBORNE SEARCH AND TRACK APPLICATION.