QUANTUM WELL INFRARED SOURCES

RESEARCH WILL BE CARRIED OUT ON QUANTUM WELL INFRARED SOURCES EMPLOYING RESONANT TUNNELING AND INTRABAND TRANSITIONS IN THE 3-5 MICRON AND 8-12 MICRON WAVELENGTH REGIONS. THE DEVICE STRUCTURES WHICH WE PROPOSE ARE TRIPLE BARRIER DIODES (TBDS). IN CONTRAST WITH CONVENTIONAL SOLID STATE LASERS AND LIGHT EMITTING DIODES, TBDS PROVIDE LONGER WAVELENGTH CAPABILITY DUE TO THE USE OF INTRABAND RATHER THAN INTERBND OPTICAL TRANSITIONS. INTRABAND TRANSITIONS DO NOT IMPOSE A LONG WAVELENGTH CUTOFF AND THEY PERMIT THE USE OF WIDE BANDGAP MATERIALS WITH FEW MATERIALS PROBLEMS. THE PHASE I WORK WILL BE DEVOTED ENTIRELY TO DEVICE DESIGN. THE DESIGN WORK WILL INVOLVE OPTIMI-ZATION OF RDIATIVE RESONANT TUNNELING AND SUPPRESSION OF NONRADIATIVE TUNNELING. THIS WORK WILL BENEFIT FROM THE CONSIDERABLE PROGRESS WHICH HAS BEEN MADE IN THE DEVELOPMENT OF DOUBLE BARRIER DIODES (DBDS). THE MAIN GOAL OF THIS WORK WILL BE TO DETERMINE THE FEASIBILITY OF USING TBDS AS INFRARED COUNTERMEASURES (IRCM) SOURCES. SPONTANEOUS AND STIMULATED EMISSION WILL BE CONSIDERED IN DETAIL FOR DEVICES WHICH OFFER THE POSSIBILITY OF STIMULATED EMISSION (LASER ACTION) AND HIGH POWER OUTPUT WITH EFFICIENT CONVERSION OF ELECTRICAL POWER INTO OPTICAL POWER.