Coupled mode approach to square gradient Bragg reflection resonances in corrugated dielectric waveguides

摘要

We demonstrate the appearance of unexpected reflection resonances incorrugated dielectric waveguides. These are due to the curvature of theboundary. The effect is as strong as the ordinary Bragg resonances, and reducesthe transmission through our waveguide by 20%. It is thus of high relevance forthe design of optimized waveguiding structures. We validate our analyticalpredictions based on coupled mode theory by a comparison to numericalsimulations.