Gain noise reduction in InGaAs photoconductive detectors by hole sweep-out effect

This paper describes results of an investigation on current gain and noise mechanisms in InGaAs photoconductive detectors. Current gain and frequency response time are shown to be determined by hole sweep-out time. Excess gain noise is revealed to be dependent on the illuminating light spot size due to the hole sweep-out effect. It is expected that excess gain-noise-free detection can be achieved by minimizing the illuminating spot size.