Interdigitated Al0.48In0.52As/Ga0.47In0.53As photoconductive detectors

Abstract
We report a high performance interdigitated Al0.48In0.52As/Ga0.47In0.53As heterostructure photoconductive detector for high bit‐rate, single‐mode telecommunication applications. The detector shows a rise time of 80 ps, a fall time of 1.2 ns, and a peak responsivity seven times better than that of a pin photodiode. Our study shows that the long fall time is due to a slow minority‐carrier (hole) drift velocity coupled with a two‐dimensional effect. We have also tested the demodulation characteristics of the detector at frequencies as high as 2.7 GHz. Furthermore, we have investigated the noise properties of the detector in the frequency band of 100 MHz–1.1 GHz.