Selectivity of dominant surface plasmon polariton modes using thin metal waveguides with grating structures

Abstract

Abstract The conversion of incident light to surface plasmon polaritons (SPPs) was verified for a dielectric-metal-dielectric waveguide with a grating structure. The dominant SPP mode with respect to the propagation distance could be selected by adjusting the thickness of the gold film. To realize highly efficient light-to-SPPs conversion, the grating parameters for a realistic length of plasmonic waveguides were optimized using a recently developed numerical technique, FDCFD-FILT. This novel technique is the combination of finite-difference complex-frequency-domain (FDCFD) with fast inversion of laplace transform (FILT) and a powerful tool for designing plasmonic waveguides and investigating propagation characteristics efficiently.