SELF-CONSISTENT APPROACH TO THERMAL EFFECTS IN VERTICAL-CAVITY SURFACE-EMITTING LASERS

A self-consistent theory for semiconductor lasers, in which plasma and lattice temperatures are treated as two independent variables, is pre sented. This theory consists of a set of coupled equations for the tot al carrier density, field amplitude, and plasma and lattice temperatur es with the coupling that is due to phonon-carrier scattering and to t he band gap's dependence on lattice temperature. The self-consistent t heory is then employed to study thermal effects in vertical-cavity sur face-emitting lasers. We first investigate the plasma heating by solvi ng the stationary (cw) solution of the set of equations with a fixed l attice temperature. The solution is studied systematically with respec t to different parameters for both hulk and quantum-well media. Signif icant plasma-heating effects are found. These include the carrier-dens ity dependence on pumping, decrease of input-output efficiency, depend ence of the cw frequency shift on pumping, and a pronounced Pauli-bloc king effect that is due to plasma heating. Furthermore, we solve the w hole set of equations, including that for lattice temperature. We show that the output power is strongly saturated or switched off with an i ncrease of pumping. Details of the saturation depend on the position o f the cavity frequency in the gain spectrum and on the heat transfer r ate from the lattice to the ambient. (C) 1995 Optical Society of Ameri ca