SURFACE EMITTING LASER ARRAY FOR UAV AUTOMATIC LANDING

WE PROPOSE TO DEVELOP A LOW-COST TECHNIQUE FOR UAV AUTOMATIC LANDING, USING A HIGH-DENSITY ARRAY OF SURFACE EMITTING LASERS (SEL) FOR ACTIVE IMAGING OF RUNWAY AND ACTIVE COMPUTING OF RANGE. WE WILL DEVELOP THE SEL ARRAY USING INGAAS/GAAS MULTIPLE QUANTUM WELLS (MQWS) SANDWICHED BETWEEN TWO DISTRIBUTED BRAGG REFLECTORS (DBR) OF GAAS/ALAS. THE MQWS AND DBR WILL BE FABRICATED ON GAAS SUBSTRATE IN TANDEM BY MOLECULAR BEAM EPITAXY (MBE). THE TWO-DIMENSIONAL ARRAY OF THE MQW LASERS WILL LASE PERPENDICULAR TO THE SURFACE OF THE SUBSTRATE AND THE EMITTED POWER FROM EACH LASER CAN BE CONTROLLED INDEPENDENTLY AND COHERENTLY. IN ADDITION, WE WILL DEVELOP A PHOTODETECTOR PLACED NEXT TO EACH LASER PIXEL, RESULTING IN A 2-DIMENSIONAL ARRAY OF RADAR ELEMENTS, WHICH WILL TAKE IMAGES OF THE RUNWAY AHEAD TOGETHER WITH RANGE MEASUREMENTS. THE MAJOR PHASE I TASK IS TO CONCEIVE AND DESIGN THE ARRAY LAYOUT, THE ON-CHIP BIAS/ADDRESS CIRCUIT AND THE CONTROL PROCESSOR NEEDED FOR THE ARRAY OPERATION AND IMAGE GENERATION AND RANGE COMPUTATION. THIS IS FOLLOWED BY A DELINEATION OF AN MBE PROCESS TO FABRICATE THE MULTIPLE LAYERS FOR THE SEL AND DETECTORS ALL ON A SINGLE GAAS WAFER. THE RESULTANT SEL RADAR ARRAY WILL BE USED FOR GENERATING MODULATED IMAGES WITH HIGH RESOLUTION AND HIGH DYNAMIC RANGE, WITH CORRESPONDING RANGE VALUES, THUS MAKING IT IDEAL FOR AUTOMATIC LANDING SYSTEMS FOR UAVS AND LANDING AID SYSTEMS FOR MANNED AIRCRAFT. AUTOMATIC LANDING SYSTEMS FOR ALL AIRCRAFT, AUTONOMOUS NAVIGATION SYSTEMS, OPTICAL COMPUTING, OPTICAL SIGNAL PROCESSING, NEURAL NETWORKING AND INFRARED SCENE GENERATION.