Model for surface plasmon polariton mediated interaction between two dielectric-filled nanowaveguides

Abstract

We propose an analytical model that describes the interaction between two apertures based on the excitation and propagation of surface plasmon polaritons. The model assumes no fitting parameters, and only requires coefficients that describe elementary processes occurring with a single aperture. We then use the model to predict both the far-field transmission and the near field intensity of two dielectric-filled cylindrical nanowaveguides separated by a varying distance. The choice of material and geometry for the nanowaveguides is based on a previous study where it was demonstrated that transmission of more than 40% can be achieved through isolated waveguides of diameter less than one tenth of the incident wavelength. In this current study, we found that both the transmission and the near field intensity of a nanowaveguide pair display an oscillatory behavior, however the oscillations in the near field intensity curve decay more rapidly. We compared the model predictions with results from three dimensional finite element simulations and the two are in excellent agreement. In addition, we analyzed the dependence of transmission on the polarization of the incident light and found that the interaction is negligible when the axis connecting the two waveguides is perpendicular to the polarization of the incident light.