LINEWIDTH ENHANCEMENT FACTOR AND NONLINEAR GAIN IN ZNSE SEMICONDUCTOR-LASERS

We have investigated the effects of the Coulomb interaction on the opt ical gain and the refractive index of ZnSe semiconductor lasers. The C oulomb interaction increases the differential gain, leading to a decre ase of the threshold carrier density. Its influence on the linewidth e nhancement factor and the nonlinear gain coefficient is relatively sma ll because it increases both the gain and the refractive index simulta neously. We have compared the linewidth enhancement factor alpha and t he nonlinear gain coefficient epsilon for ZnSe and GaAs lasers with th e effects of the Coulomb interaction taken into account. For typical v alues of total cavity losses, the values of alpha and epsilon are high er for ZnSe lasers compared with GaAs lasers.