A regularized adaptive spatial resolution technique for fast and accurate analysis of metal–dielectric crossed gratings

Abstract

The application of regularized jump points has been proposed [Khavasi and Mehrany in Opt Commun 284(13):3211–3215, 6] as an adaptive spatial resolution (ASR) technique to improve the convergence of the Fourier modal method (FMM) in the analysis of one-dimensional periodic structures. We extend this approach to obtain the optical response of metal–dielectric crossed gratings, two-dimensional periodic structures with a high-contrast permittivity distribution. A metallic grid and a slab of split-ring resonators are analyzed using the proposed ASR technique, and the results compared with those obtained using the conventional ASR technique and FMM. The results show that, by adequately choosing the discontinuity points of the dielectric function in the new coordinates, the convergence speed and accuracy of the proposed ASR technique are further increased compared with the conventional ASR technique.