GRATING-COUPLED SURFACE-EMITTING LASERS WITH INTEGRATED CORNER REFLECTORS

Grating-coupled surface-emitting InGaAs/AlGaAs lasers with a single la rge area output coupler were fabricated by integrating a second order surface grating with corner reflectors. The grating as well as the cor ner reflectors were fabricated using electron beam lithography and che mically assisted ion beam etching, producing a uniform rectangular gra ting and high quality corner facets. A thin etch-stop layer incorporat ed in the epitaxial structure made it possible to combine precise cont rol of the grating position with a strained layer SQW-GRINSCH structur e. Well behaved lateral modes were observed in 70-mum-wide lasers, emi tting narrow beams in both the lateral and the longitudinal direction. Threshold current densities as low as 99 A/cm2 were measured for 1200 -mum-long lasers.