Highly efficient laterally oxidized λ=950 nm InGaAs-AlGaAs single-mode lasers

Results on laser diodes operating in single lateral and longitudinal mode around an emission wavelength of 950 nm are reported. Index guiding and current confinement in these devices are provided by a laterally oxidized aperture. The effective refractive index step of the lateral waveguide can be adjusted by the position and the thickness of the aperture. Structures with different effective refractive index steps and various aperture widths (3-7 μm) have been characterized in CW operation at room temperature. Maximum output powers of 170 mW have been achieved. Due to the lower refractive index step compared to ridge-waveguide lasers, a larger lateral width of the optical waveguide can be chosen, preserving single-mode operation. Because of the low series resistance, wall-plug efficiencies up to 638 have been realized with these devices