GaAs-AlxGa1−xAs buried-heterostructure lasers grown by molecular beam epitaxy with Al0.65Ga0.35As (Ge-doped) liquid phase epitaxy overgrown layer for current injection confinement

GaAs-AlxGa1−xAs buried-heterostructure (BH) lasers were fabricated by a molecular beam epitaxy/liquid phase epitaxy (MBE/LPE) hybrid technique. The BH lasers with 5 μm stripe width have cw current thresholds as low as 15 and 26 mA for diode lengths of 250 and 380 μm, respectively. We also introduced a new, simple, and convenient method for achieving efficient lateral current injection confinement in BH lasers by using the highly resistive LPE-grown Al0.65Ga0.35As (lightly Ge-doped) layer. This technique also automatically self-aligns the current injection stripes to the active stripes.