<title>High-gain APD array for photon detection</title>

Abstract

Arrays of high speed, high gain avalanche photodiodes (APDs) have been developed for use as high sensitivity optical photon detectors. The 1 mm<SUP>2</SUP> area APD pixels yield a maximum avalanche gain of 40,000 and a high signal-to-noise ratio with only moderate cooling (-22 degrees to -43 degrees C). These devices demonstrate 70% detection efficiency for 6 photon optical pulses and 35% detection efficiency for 3 photon optical pulses. The rise time is less than 2 nsec, and the fall time less than 7 nsec. Pixellating the PAD into a monolithic array will significantly reduce the cost per pixel compared to discrete devices. These devices will have great utility in various applications, ranging from high energy physics to biological instrumentation. The measured performance of these APD arrays as optical detectors will be discussed.