Stabilization of self-focusing instability in wide-aperture semiconductor lasers

Abstract

A mechanism for the stabilization of the output of filamentary broad-area edge-emitting semiconductor lasers is analyzed experimentally and theoretically. This mechanism occurs when the carrier density is profiled in the transverse direction. The laser structure consisted of a wide-aperture edge-emitting laser diode operating in pulsed mode to avoid thermal guiding effects. The injection current profile was modified from the usual step-function case to a Lorentzian-like profile through the inclusion of a 10 mum p-type epitaxial spreading layer. The resulting nonlinear transverse mode is described and the possibility of its observation in two transverse dimensions is discussed.