Reception of radiation by bent dielectric waveguides

Abstract

It is demonstrated that bent dielectric waveguides can convert incident radiation into guided-mode power. A beam-propagation method simulation of the effect in a slab single-moded weakly guiding waveguide is shown to be in accordance with a theoretical formulation of the process. I establish a simple analytical approximation for power captured by a curved slab guide from an incident Gaussian-shaped beam. The results demonstrate general agreement with the reciprocity principle: the most efficient radiator is the best receiver, and radiation incident from outside the bend couples most efficiently into the guide.