Dielectric based resonant guided wave networks

Eyal Feigenbaum,Harry A Atwater

doi:10.1364/oe.20.010674

Abstract

Resonant guided wave networks (RGWNs) are demonstrated to operate based on dielectric waveguides, broadening the scope of this optical design approach beyond plasmonics. The intersection of two dielectric waveguides that is modified by a tuned scattering particle is shown to function as an equal power splitting element, a key enabler of resonant guided wave networks. We describe structures composed of two types of waveguides, Si slabs and SOI ribs, at the telecom frequencies using both, Au and etch, based scatterers.

Highlights

A new class of optical artificial materials [1,2,3,4], known as resonant guided wave networks (RGWNs), was reported [5]
In resonant guided wave networks, localized waves resonate in closed paths throughout a network of isolated waveguides connected by wave splitting elements
We report here designs for resonant guided wave networks that do not rely on plasmonic structures but rather on standard dielectric waveguides

Summary

Introduction

A new class of optical artificial materials [1,2,3,4], known as resonant guided wave networks (RGWNs), was reported [5]. By controlling the properties of each splitting element and every waveguide, the network intereference and resonances can be determined and the optical function of the network This allows for a compact design of complex interferometric devices, such as color routers [6] or possibly of mode converters. It was found that at the intersection of two metal-insulator-metal (MIM) waveguides [7,8], (see Fig. 1(c)) with subwavelength inter-metal gap spacing, the power splits between the outputs This distinctive behavior stems from the slow wave nature of the plasmonic mode propagating in metal-insulator-metal waveguides, which has a mode profile comprised of many higher wave vector components [9]. Since plasmonic structures inherently support design of power splitting elements, it is straightforward to show that a network of intersecting metal-insulator-metal waveguides can give rise to a resonant guided wave network. Such dielectric resonant guided wave networks could mitigate the inherent losses of plasmonic structures and enable integration with more commonly used components of photonic circuitry

Power splitting at the intersection of two waveguides without scatterers

Two dimensional analysis of dielectric-based resonant guided wave networks

Analysis of three dimensional dielectric based scatterers

Findings

Conclusion