Sensitivity of optimization of mid-infrared InAs/InGaSb laser active regions to temperature and composition variations

Abstract

We calculate the temperature dependence of the threshold current density Jth in optimized (minimal Jth) and unoptimized InAs/InGaSb superlattices. We find that the threshold current density of the unoptimized superlattice is well described by Jth∝eT/T0, with T0∼32 K from 25 to 275 K. This is the first microscopic calculation for these superlattices which indicates that Jth is well described by an empirical exponential form. In contrast, the threshold current density of the optimized superlattice is not well parametrized by a characteristic temperature T0. This superlattice is only optimized between 250 and 350 K, due to the sharp structure of the intersubband absorption spectrum. We also consider the effect on Jth of uncertainties in layer thicknesses.