Dispersion Characteristics of Guided Plasmonic Modes in Metallic Slot Waveguides Using Method of Lines

In this paper we analysed the dispersion characteristics of the mode supported by a plasmonic slot waveguide structure, using Method of Lines (MoL) and Finite Element Method (FEM). Metal slot waveguides, unlike nano-metal strip waveguides, can support bound plasmon mode for wavelengths above optical regime. The propagation properties of the mode is studied as a function of operating wavelength. Metallic slot waveguides provide the confinement of the mode to lateral size many decade times smaller than the free-space wavelength. The dependance of the mode properties on the guiding geometry and structural parameters is also analysed. It is observed that the slot width, thickness, and refractive index of the material filling the slot region strongly influence the dispersion characteristics of the mode.