Output coupling and distributed feedback utilizing substrate corrugations in double-heterostructure GaAs lasers

Conventional double-heterostructure lasers with a thin n-Ga1/sub -//suby/Al/suby/As layer grown on a periodically corrugated n-GaAs substrate have been operated at room temperature. The evanescent tail of the guided mode interacts with the substrate corrugation to produce both distributed feedback and output coupling perpendicular to the waveguide. A single polarized low-divergence (0.65degreetimes10degree) output beam at 8825 A radiated normal to the waveguide was obtained from such a diode with cleaved end facets at a threshold current of 4.1 kA/cm2. (auth)