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

Three 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 similar to 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 similar to 5.5 A/cm(2) per QD layer and 1.5 cm(-1) were deduced respectively. For an infinite cavity length a minimum threshold current density of similar to 9 A/cm(2) per QD layer was inferred