Surface-emitting GaInAsP/InP laser with low threshold current and high efficiency

Abstract

A buried-heterostructure laser has been developed whose output is deflected to a direction perpendicular to the substrate surface by a monolithically integrated 45° (parabolic) mirror. The latter is fabricated by smoothing a chemically etched multistep structure using a mass-transport phenomenon. The present devices show threshold current as low as 12 mA, differential quantum efficiency as high as 47% and a surface-emitting far-field pattern with a main lobe as narrow as 12°.