Spatial mode discrimination and control in high-power single-mode constricted double-heterojunction large-optical-cavity diode lasers

Mode discrimination and control in high-power constricted double-heterojunction large-optical-cavity (CDH-LOC) lasers are determined by three factors: a sharp lateral variation in radiation confinement factor, a ‘‘built-in’’ dielectric W guide in the plane of the junction, and the influence of gain-induced index depressions on the W guide. Excellent far-field pattern fits are achieved by using the actual geometries and compositions of two high-power CDH-LOC structures, and gain-induced (bulk) index depressions in the −0.02 to −0.03 range. The dependence of mode discrimination on the gain-induced index depression allows tailoring CDH-LOC devices for specific spatial mode operation.