Efficient perturbative framework for coupling of radiative and guided modes in nearly periodic surfaces

Abstract

Brute-force simulations are typically used to investigate coupling between radiative and guided waves in slowly varying photonic structures, but when these structures are large, such simulations become too cumbersome. Here, a semianalytical formalism is introduced that computes this coupling accurately and inexpensively, motivating its use in the design of large-area optical metasurfaces.