Radiation from concentric-circle grating, surface-emitting planar waveguides: The volume current method

Abstract

This letter describes the volume current boundary perturbation method and uses this method to find the field radiated by a set of concentric rings located at the film-cover interface of a three-layer, planar optical waveguide. Waveguides with annular and full (extending from the origin) sets of circular gratings, and with both traveling and standing guided waves, are analyzed. The resulting analytical expression for the radiation field and far-field intensity patterns are compared with results of the field-expansion boundary perturbation method.