Surface-emitting laser

Abstract

A surface-emitting laser contains an optical cavity including a multiple quantum well (MQW) active region providing a source of optical emission in use. Top and bottom mirrors are disposed respectively above and below the MQW active region. The MQW active region is profiled so that it has a greater number of quantum wells in a central portion thereof than in a peripheral portion thereof. In alternative embodiments, a current-guiding region is profiled so that it has a first current-guiding portion with a relatively smaller aperture therethrough extending over a central portion of the MQW active region, and a second current-guiding portion with a relatively larger aperture therethrough; and one of the mirrors has a layer structure which, in a central portion of the cross-sectional area of such mirror, is different to that in a peripheral portion of said cross-sectional area.

Dependencies are inferred from the claim text.