Symmetric metal slot waveguides with nonlinear dielectric core: bifurcations, size effects, and higher order modes

TL;DR

This paper investigates nonlinear wave propagation in symmetric metal slot waveguides with a Kerr dielectric core, revealing mode bifurcations, size effects, and invariance properties of certain modes through semi-analytical models.

Contribution

It introduces two independent semi-analytical models for analyzing nonlinear slot waveguides and characterizes mode behaviors, including bifurcations and size effects, with analytical approximations.

Findings

Identification of symmetric, antisymmetric, and asymmetric modes

Mode bifurcation and size effect analysis

Invariance of the first asymmetric mode's dispersion curve at high propagation constants

Abstract

We study the nonlinear waves propagating in metal slot waveguides with a Kerr-type dielectric core. We develop two independent semi-analytical models to describe the properties of such waveguides. Using those models we compute the dispersion curves for the first ten modes of a nonlinear slot waveguide. For symmetric waveguides we find symmetric, antisymmetric, and asymmetric modes which are grouped in two families. In addition, we study the influence of the slot width on the first symmetric and asymmetric modes, and we show that the dispersion curve of the first asymmetric mode is invariant with respect to the slot width for high propagation constant values and we provide analytical approximations of this curve.