Gain nonlinearities in semiconductor lasers and amplifiers

A concise and fundamentally straightforward physical model that accounts for the nonlinear gain in both semiconductor amplifiers and lasers is presented. Calculations based on this model yield results that agree very well with observed transient gain recovery dynamics in semiconductor laser amplifiers. The value of the symmetric steady-state gain suppression factor is found to be β=1.67×10−23 m3 in good agreement with experiment. The model accounts for a wavelength dependence of the asymmetric part of the nonlinear gain observed in direct mixing experiments observed in semiconductor lasers.