UV-Enhanced APD Receiver for Free Space Optical Communications

Free space optical communication (FSOC) systems offer rapid data transfer rates, allowing practical wireless relay of complex data sets. To further promote the use of this technology for medium-range optical communication links operating with eye-safe ultra-violet (UV) sources, compact and robust receiver modules with high responsivity that operate in a range of environmental conditions are required. To meet this challenge, scientists at Radiation Monitoring Devices, Inc. (RMD) will further advance our state-of-the-art silicon avalanche photodiode (APD) technology. Our goal is to realize a manufacturing process that reliably produces APDs with quantum efficiencies of greater than 80% in the 350 to 380 nm wavelength range, operation at temperature ranging from -40 to 70 degrees C, bandwidths of at least 100 MHz and less than 90 V operation bias. This effort will build upon our established planar processing methods, without sacrificing its advantages; namely, large area APD detectors with high quantum efficiencies and signal gains greater than 1000. When coupled to high-speed amplification electronics, a receiver module will be realized that meets required performance specifications as defined by the US Army.