2.1 MICROMETER LIDAR DETECTOR

THIS PROPOSAL ADDRESSES THE NEED FOR A HIGH DETECTIVITY PHOTOVOLTAIC LIDAR DETECTOR WITH A SPECTRAL RESPONSE PEAK IN THE 2.1 UM SPECTRAL REGION TO MATCH THE EMISSION FROM THEHIGH PERFORMANCE HO:YAG SOLID STATE LASER PRESENTLY UNDER DEVELOPMENT. DUE TO THE FACT THAT THERE ARE FEW APPLICATIONS WHICH REQUIRE GOOD DETECTORS IN THIS WAVELENGTHREGION, NO HIGH PERFORMANCE DETECTORS ARE AVAILABLE. TWO SEMICONDUCTOR MATERIALS ARE PROMISING FOR YIELDING HIGH PERFORMANCE 2.1 M PHOTOVOLTAIC DETECTORS: HGCDTE AND INGAAS. THE FORMER MATERIAL IS UNDER INTENSE INVESTIGATION FOR USE IN THE 8-12 AND, TO A LESSER EXTENT, THE 3-5 M SPECTRAL REGION, BUT IS EXTREMELY DIFFICULT TO WORK WITH ANDVERY EXPENSIVE. THE LATTER, IS METALLURGICALLY BETTER BEHAVED, AND IS IN WIDE USE IN THE 1.3 AND 1.55 M SPECTRAL REGIONS FOR FIBER-OPTIC APPLICATIONS. THIS MATERIAL CAN BE MADE TO HAVE A SPECTRAL RESPONSE PEAK AT 2.1 M. WE PROPOSE TO INVESTIGATE THE GROWTH OF INGAAS BY THE MOCVD TECHNOLOGY FOR USE AS A 2.1 M PHOTODETECTOR. THE MOCVD GROWTH PROCESS MAKES POSSIBLE 1-STEP SYNTHESIS OF THE PHOTODIODE STRUCTURE, AND THEREFORE HOLDS THE PROMISE OF LEADING TO LOW-COST, HIGH PERFORMANCE PHOTODIODES WITH A 2.1 M SPECTRAL PEAK. THE PROPOSED WORK IS COMPATIBLE WITH PRESENT, IN-HOUSE PROGRAMS FOR GROWING INP BASED MATERIALS.