Analysis of Rib, Slot, and V-Shaped Surface Plasmonic Waveguides Using a Full-Vectorial Imaginary-Distance Finite-Element Beam Propagation Method

This research studies the surface plasmon polariton (SPP) waveguides using the finite element imaginary-distance beam propagation method (FE-ID-BPM). The rib waveguide, slot waveguides, channel plasmon, and V-shaped waveguides are investigated. The effective indices, propagation lengths, modal field profiles, and dispersion relations are calculated for various structure papramters. In the rib waveguide with a layer of low-index material located between the metal cap and the high-index material layer, various layer thicknesses are examined to understand different guided- mode characteristics. In the slot waveguide, a high-index material is introduced in the slot and mode field confinement and propagation length analyzed for different widths and heights of the high-index material for possible loss reduction. In the V-shaped waveguide with a metal layer of finite thickness, the characteristics of the channel plasmon polariton (CPP) and wedge plasmon polariton (WPP) modes for different metal-layer thicknesses are studied.