Carrier-induced change in index, gain, and lifetime for (InAs)1/(GaAs)4 superlattice lasers

Abstract
The carrier density dependence of gain, index, and carrier lifetime has been measured for (InAs)1/(GaAs)4 short‐period superlattice lasers. The 500‐μm‐long lasers have a threshold current density of 200 A/cm2 and exhibit a small carrier‐induced change in refractive index (ΔnN∼2×10−22 cm3). The small ΔnN also results in small linewidth enhancement factor (α∼1.1) of these lasers. The measured dependence of carrier lifetime on carrier density can be fitted to a bimolecular recombination model which suggests that radiative recombination is the dominant recombination mechanism in these structures.