All Dielectric Metamaterial Loaded Tunable Plasmonic Waveguide

TL;DR

This paper proposes a tunable plasmonic waveguide loaded with all dielectric anisotropic metamaterials, analyzing its propagation characteristics through theoretical and numerical methods, highlighting its potential for deep sub-wavelength optical applications.

Contribution

It introduces a novel all dielectric metamaterial loaded plasmonic waveguide with tunable properties, analyzed both analytically and numerically, which has not been previously explored in plasmonic waveguides.

Findings

Propagation characteristics vary significantly with fill factor.

Effective Medium Theory accurately models the anisotropic ridge.

The structure offers tunability for sub-wavelength optical devices.

Abstract

In this article, a 2D plasmonic waveguide loaded with all dielectric anisotropic metamaterial, consisting of alternative layers of Si-SiO2, has been theoretically proposed and numerically analyzed. Main characteristics of waveguide i.e. propagation constant, propagation length and normalized mode area have been calculated for different values of ridge width and height at telecommunication wavelength. The respective 1D structure of the waveguide has been analytically solved for the anisotropic ridge as a single uniaxial medium with dielectric tensor defined by Effective Medium Theory (EMT). The 2D structure has been analyzed numerically through FEM simulation using Mode analysis module in Comsol Multiphysics. Both the EMT and real multilayer structure have been considered in numerical simulations. Such structure with all dielectric metamaterial provides an extra degree of freedom namely fill factor, fraction of Si layer in a Si-SiO2 unit cell, to tune the propagation characteristics compared to the conventional DLSSP waveguide. A wide range of variations in all the characteristics have been observed for different fill factor values. Besides, the effect of the first interface layer has also been considered. Though all dielectric metamaterial has already been utilized in photonic waveguide as cladding, the implementation in plasmonic waveguide has not been investigated yet to our best knowledge. The proposed device might be a potential in deep sub-wavelength optics, PIC and optoelectronics.