Numerical simulation studies of nano-scale Surface plasmon components: waveguides, splitters and filters

TL;DR

This study uses numerical simulations to demonstrate innovative nano-scale surface plasmon components, including waveguides, splitters, and filters, for high-density integrated photonic applications.

Contribution

The paper introduces a novel MDM waveguide design with a Y-branch for high integration and a compact periodic tooth structure for efficient wavelength filtering.

Findings

Y-branch waveguide achieves large branching angle (~180°)

Filter transmittance exceeds 92% in a compact size

Structures enable ultra-compact photonic filtering devices

Abstract

In this paper, we theoretically and numerically demonstrate a two-dimensional Metal-Dielectric-Metal (MDM) waveguide based on finite-difference time-domain simulation of the propagation characteristics of surface plasmon polaritons (SPPs). For practical applications, we propose a plasmonic Y-branch waveguide based on MDM structure for high integration. The simulation results show that the Y-branch waveguide proposed here makes optical splitter with large branching angle (~180 degree) come true. We also introduce a finite array of periodic tooth structure on one surface of the MDM waveguide which is in a similar way as FBGs or Bragg reflectors, potentially as filters for WDM applications. Our results show that the novel structure not only can realize filtering function of wavelength with a high transmittance over 92%, but also with an ultra-compact size in the length of a few hundred nanometers, in comparison with other grating-like SPPs filters. The MDM waveguide splitters and filters could be utilized to achieve ultra-compact photonic filtering devices for high integration in SPPs-based flat metallic surfaces.