Low-threshold laterally oxidized GaInP-AlGaInP quantum-well laser diodes

Low-threshold, high-efficiency edge-emitting visible AIGaInP-GaInP laser diodes using a buried AlAs native oxides for carrier and optical confinement are described. The lasers incorporate a thin AlAs layer in the upper cladding region, which when laterally wet oxidized, forms a narrow aperture. The lasers operate with room temperature, continuous-wave (CW) threshold currents of 11 mA with external differential quantum efficiency of 34% per facet for an uncoated 300-μm-long 3.5-μm-wide device. As-fabricated lasers exhibited modest performance under CW operation. Post-fabrication annealing was shown to dramatically improve the device characteristics.