Strained-layer InGaAs-GaAs-AlGaAs buried-heterostructure quantum-well lasers by three-step selective-area metalorganic chemical vapor deposition

Strained-layer In_xGa_1-xAs-GaAs-Al_yGa_1-yAs buried-heterostructure (BH) quantum-well lasers have been fabricated using three-step selective area atmospheric pressure metal-organic chemical vapor deposition. Selective-area epitaxy is used to produce BH lasers involving only GaAs on GaAs regrowth, eliminating the detrimental effects associated with exposed Al_yGa_1-yAs found in other fabrication methods. Additionally, selective-area epitaxy provides inplane bandgap energy control to fabricate BH devices with different wavelengths on the same wafer. Threshold currents as low as 11 mA are obtained for a 540-μm-long, 4-μm-wide device with uncoated cleaved facets. The devices operate at room temperature to more than 200 mW/uncoated facet with 40% external differential quantum efficiency. In-plane bandgap energy control results in a wide range of possible laser emission wavelengths for BH lasers grown on the same substrate