High‐gain low‐threshold InAs/InGaAs/GaAs quantum dot lasers emitting around 1300 nm

Abstract

AbstractThree semiconductor laser structures containing 1, 3 and 5 layers of self organized InAs/InGaAs/GaAs quantum dots (QDs) have been grown by Molecular Beam Epitaxy. Broad area lasers were processed from the grown wafers and tested. These structures show a linear increase of the modal gain with the number of QDs layers with an average modal gain per QDs layer of ∼5 cm–1. A maximum modal gain of 25 cm–1 was obtained at room temperature (RT) from the sample containing 5 layers of QDs. A transparency current density and a low internal loss value of ∼5.5 A/cm2 per QD layer and 1.5 cm–1 were deduced respectively. For an infinite cavity length a minimum threshold current density of ∼9 A/cm2 per QD layer was inferred. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)