InAs quantum-dot GaAs-based lasers grown on AlGaAsSb metamorphic buffers

Self-assembled InAs quantum-dot lasers grown by molecular-beam epitaxy using an AlGaAsSb metamorphic buffer layer on a GaAs substrate are reported. The resulting quantum-dot ensemble has a density ${\text{>3×10}}^{10}/{\mathrm{cm}}^2$ and a ground-state transition ranging from 1.46 to 1.63 μm. Pulsed, room-temperature operation generates lasing from the first excited state transition at wavelengths ranging from 1.27 to 1.34 μm. The minimum threshold current density (304 A/cm²) is achieved for a 7.7 mm cavity with cleaved, uncoated facets.