Gain nonlinearities due to carrier density dependent dispersion insemiconductor lasers

Semiconductor-field interaction is analyzed by using a semiclassical density-matrix approach. Using an exact elimination procedure for the dipole moments, corrections to the standard rate equation are obtained and shown to result in gain nonlinearities. The gain nonlinearities are due to carrier-density-dependent dispersion at the lasing frequency. Using available measured data of the frequency dependence of the carrier-induced refractive index change, gain compression coefficients in agreement with experimental values are obtained