Abstract
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.