High-speed junction-depleted Ga0.47In0.53As photoconductive detectors

A high-speed junction-depleted Ga0.47In0.53As photoconductive detector without making use of radiation damage to the sample is reported. The detector has a light absorbing region in the n−layer of an unbiased p-n junction. As a result of the built-in field associated with the p-n junction, the carriers generated far from the surface were removed, leading to a picosecond response time. When tested by 100-ps, 1.55-μm light pulses, the detector showed a fall time of 90 ps with an external gain >1.3 (no antireflection coating). Receiver sensitivity at 1 Gb/s was −25.3 dBm at 1.55 μm and an error rate of 10−9.