In this article we present the analysis and simulation of nonlineariti
es in the GaInAs/InP p-i-n photodetector at high illuminations. It is
shown that the nonlinearities are generated principally in the low-fie
ld region of the intrinsic layer. The frequency response, especially f
or the nonlinear characteristics, is illustrated to differ significant
ly between top-illumination and substrate-illumination operations at c
ommon biasing level. (C) 1996 John Wiley & Sons, Inc.