High-power and long-lifetime InAs/GaAs quantum-dot laser at 1080 nm

High power and long lifetime have been demonstrated for a semiconductor qua ntum-dot (QD) laser with five-stacked InAs/GaAs QDs separated by an InGaAs strain-reducing layer (SRL) and a GaAs spacer layer as an active medium. Th e QD lasers exhibit a peak power of 3.6 W at 1080 nm, a quantum slope effic iency of 84.6%, and an output-power degradation rate of 5.6%/1000 h with co ntinuous-wave constant-current operation at room temperature. A comparative reliability investigation indicates that the lifetime of the InAs/GaAs QD laser with the InGaAs SRL is much longer than that of a QD laser without th e InGaAs SRL. This improved lifetime of the QD laser could be explained by the reduction of strain in and around InAs QDs induced by the InGaAs SRL. ( C) 2001 American Institute of Physics.