Gain Characteristics of Self-Assembled InAs/GaAs Quantum Dots

Abstract

The gain characteristics of stacked self-assembled InAs/GaAs quantum dots (QDs) with an inhomogeneous broadening of the order of 100 meV are studied in comparison to an InGaAs quantum well. The QDs exhibit gain already at low current densities of ∼25 Acm—2 per QD layer, but the peak gain rises slowly with increasing current density. The energy of the peak gain is shifted from the low energy tail of the QD emission at low injection towards the wetting-layer at high injection.