Threshold current of single quantum well lasers: The role of the confining layers

Abstract

The threshold current density of single quantum well (SQW) GaAs/GaAlAs lasers is calculated, taking into account the carrier populations of the confining layer. We find that these populations are significant when compared to those of the quantum well. This effect explains the better performance of the graded-index separate confinement SQW laser when compared to the separate confinement heterostructure laser, as well as the T0 performance of such lasers.