Native-oxide defined In0.5(Al<i>x</i>Ga1−<i>x</i>)0.5P quantum well heterostructure window lasers (660 nm)

Abstract

Data are presented demonstrating In0.5(AlxGa1−x)0.5P quantum well heterostructure lasers with extended current-blocking windows (∼75 μm/window) that exhibit significant improvements in output power (∼2×) compared to lasers with no windows. The windows and active stripes are defined by the formation of a thin (∼1000 Å, patterned) native oxide via H2O vapor oxidation (550 °C) of the high-gap In0.5(AlxGa1−x)0.5P upper confining layer. Devices operating at ∼660 nm with a 40 μm wide emitting aperture (∼500 μm cavity) and ∼75 μm windows (total window length ∼150 μm) exhibit 300 K continuous output powers ≳130 mW/facet (uncoated) and pulsed output powers ≳575 mW/facet (uncoated). Improvements in output power result from decreased heating at the facets and defocusing of the optical wave in the unpumped window regions.