Role of strain on threshold current, modal purity and Auger processes in strained quantum well lasers

Abstract

We present numerical calculations of material gain and threshold current density in compressively strained quantum well lasers grown on GaAs and InP. The valence bandstructure is obtained from a 4 x 4 k [middle dot] p Hamiltonian that includes the effects of strain. Calculation of the spontaneous emission rate and optical material gain proceeds directly from the bandstructure and we extract the threshold current density from the emission rate. We find that incorporating ~2% misfit strain reduces the threshold current density by 50% in the GaAs system and by 30% in the InP system. We calculate the hole masses in the presence of strain with a 6 x 6 k [middle dot] p Hamiltonian and use them to determine the effect of strain on Auger processes.