Simulation Research of Nonlinear Behavior Induced by the Charge-Carrier Effect in Resonant-Cavity-Enhanced Photodetectors

In this paper, we have calculated and discussed in detail the nonlinear effect induced by three carrier effects: free-carrier absorption, bandgap filling, and bandgap shrinkage. The central wavelength of response of resonant-cavity-enhanced (RCE) photodetectors shifts according to the change of the refractive index, and the response of a given optical wavelength simultaneously changes. With an increasing As composition of $\hbox{In}_{1 - x}\hbox{Ga}_{x}\hbox{As}_{y}\hbox{P}_{1 - y}$ and the spacer thickness, the nonlinear effect increases, but the $-$ 1-dB input saturation optical power and the $-$1-dB saturation photocurrent decrease. Bistable-state operation occurs when the input optical power is in the proper bistable region.