On the use of the Fourier modal method for calculation of localized eigenmodes of integrated optical resonators

摘要

We propose the generalization of the Fourier modal method aimed atcalculating localized eigenmodes of integrated optical resonators. The methodis based on constructing the analytic continuation of the structure'sscattering matrix and calculating its poles. The method allows one to calculatethe complex frequency of the localized mode and the corresponding fielddistribution. We use the proposed method to calculate the eigenmodes ofrectangular dielectric block located on metal surface. We show that excitationof these modes by surface plasmon-polariton (SPP) results in resonant featuresin the SPP transmission spectrum. The proposed method can be used to design andinvestigate optical properties of integrated and plasmonic optical devices.