Single-Longitudinal-Mode Selfaligned (AlGa)As Double-Heterostructure Lasers Fabricated by Molecular Beam Epitaxy

Single-longitudinal-mode selfaligned (AlGa)As double-heterostructure (DH) lasers were fabricated by two-step molecular beam epitaxial technique. The AlGaAs surface was protected by a GaAs thin layer during the photolithographic process. The GaAs was thermally etched selectively just prior to regrowth in the MBE system. There was no problem associated with the regrowth of AlGaAs using this GaAs passivation technique. The room temperature CW threshold current for a device with a 200 µm-long and 3 µm-wide stripe was 40 mA. The emission wavelength was 780 nm and a fundamental transverse mode was achieved.