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

Abstract

We demonstrate the appearance of unexpected reflection resonances in corrugated dielectric waveguides. These are due to the curvature of the boundary. The effect is as strong as the ordinary Bragg resonances, and reduces the transmission through our waveguide by 20%. It is thus of high relevance for the design of optimized waveguiding structures. We validate our analytical predictions based on coupled mode theory by a comparison to numerical simulations.

Propagation of surface plasmons on plasmonic Bragg gratings

“…where the coupling constants K s1,s2 µ,µ vanishes because of the dielectric function (11). Therefore, we have the trivial solution:…”

“…In the context of the theory of lasers, a comparison between the transfer matrix method and coupled-mode theory was given by Makino 10 . Recently, coupled-mode theory was used for studying the scattering of electromagnetic modes in a waveguide with corrugated boundaries 11 .…”

Corrugated non-stationary optical fiber

“…Interesting theoretical and experimental results concerning to the propagation of electromagnetic waves in inhomogeneous or corrugated optical fibers were obtained [6][7][8][9][10]. The problems of such type are intensively studied last decade [11][12][13][14][15]. In some cases, the inhomogeneity can be described as periodic perturbation along the optical fiber axis (analogously to internal waves in the ocean [1]).…”