Singular perturbation theory of a thin film surface-polariton polarizer for a planar optical waveguide

Abstract

An on-line polarizer of the order of a millimeter in length is designed by locating a thin metal film suitably close and parallel to a dielectric film waveguide. The polarizer transmits the transverse electric guided mode of the dielectric film with negligible insertion loss. As a consequence of the phase-matched wave interaction between the surface polariton supported by the metal film and the transverse magnetic guided mode of the dielectric film, the transverse magnetic guided mode is severely attenuated resulting in a high extinction coefficient. A singular perturbation theory using multiple space scales is developed for the analysis of this thin film surface polariton polarizer for a planar dielectric film optical waveguide and illustrative numerical results are presented. The sensitivity of the performance of the polarizer to small changes in the various physical parameters is examined.