SUBMILLIAMPERE THRESHOLD CURRENT INGAAS-GAAS-ALGAAS LASERS AND LASER ARRAYS GROWN ON NONPLANAR SUBSTRATES

High performance buried heterostructure InGaAs-GaAs-AlGaAs quantum-wel l lasers and laser arrays with tight spatial confinement of the electr ical current and the optical fields have been fabricated by metalorgan ic chemical vapor deposition, The lasers are fabricated in a single gr owth step, using nonplanar substrates as a template for the active reg ion definition, CW room temperature threshold currents, as low as 0.5 mA and 0.6 mA, are obtained for as-cleaved double and single quantum-w ell lasers, respectively, External quantum efficiencies exceeding 80% are obtained in the same devices, High-reflectivity facet-coated laser s have room temperature CW threshold currents as low as 0.145 mA with 10% external quantum efficiency. Lasers made by this technique have hi gh yield and uniformity, and are suitable for low threshold array appl ications.