Surface Plasmon Resonance Absorption in a Multilayered Thin-Film Grating

Abstract

We numerically analyze surface plasmon resonance absorption of incident light energy by a multilayered grating, which consists of a stack of periodically corrugated metal and dielectric films. We apply Yasuura's modal expansion method for solving the problem of plane-wave diffraction by a multilayered grating. Employing the numerical algorithm, we evaluate the resonance absorption which is observed as dips of diffraction efficiency curves. We investigate field distributions in the vicinity of a multilayered grating when the absorption occurs. We thus show that the surface plasmons are excited on a thin metal film embedded in a multilayered grating. In view of the design of a multilayered thin-film grating, we investigate the influence of the corrugation depth and the refractive index of a substrate on characteristics of plasmon resonance absorption.