Spectral Red-Shift and Pulse Splitting in Nonlinear Dielectric-Loaded Plasmonic Waveguide

Abstract

A long-range dielectric-loaded SPP waveguide (LR-DLSPPW) featuring tight mode confinement, long propagation length, and highly nonlinear response is proposed. Finite element method (FEM) simulation of linear analysis is followed by numerical solution of the generalized nonlinear Schrodinger equation (GNLSE). Nonlinear propagation of the plasmonic-guided mode along the LR-DLSPPW is supposed to be originated from the thermo-modulational nonlinearity of the metal strip and the third-order nonlinear susceptibility of the dielectric ridge section. The results manifest the appearance of an intense spectral red-shift and self phase modulation (SPM) caused by the delayed thermo-modulational nonlinearity of metal. Increment of the input power highlights the third-order nonlinearity effect of the ridge section which is associated with the pulse splitting of the input. Low-input threshold power for the observation of nonlinear effects, due to low propagation loss of the structure and local field enhancement nature of plasmonic waves, is a distinguished feature of the proposed LR-DLSPPW configuration which is valuable for applications involving nonlinear phenomenon.