Effects of high space-charge fields on the response of microwave photodetectors

Abstract

We present simulation results, based on a one-dimensional p-i-n photodetector model, to explain the reductions in photodetector response observed at high optical powers. The nonlinear effects are attributed to the redistribution of the internal electric field due to space-charge effects created by the photocarriers. The corresponding modification of the position-dependent charge velocities results in high-frequency response reduction, roll-off reduction, and pulse narrowing. Electric field redistribution leads to two dimensional effects, which must be included for accurate modeling of milliampere photocurrents.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>