Abstract

Conventional III-V semiconductor lasers make use of an optical cavity defined by two cleaved, parallel crystal-facets that act as end mirrors for the resonator. It is in the nature of this resonator that the beam emitted by the laser is non-circular in cross-section and relatively broadly diverging. One interesting alternative approach to constructing an optical cavity for a semiconductor laser makes use of a second-order, one-dimensional grating that provides both distributed feedback and surface emission. This basic concept can be extended to two dimensions by incorporating a circularly symmetric grating into the waveguide structure of the semiconductor laser. A properly constructed circular grating would be expected to couple inward- and outward-going circular waves generated within the laser, and, at the same time, radiate a beam that is circular in cross-section and narrowly diverging.

© 1993 Optical Society of America