A plasmonic ellipse resonator possessing hybrid modes for ultracompact chipscale application

TL;DR

This paper introduces a novel plasmonic ellipse resonator with hybrid modes that supports multiple resonances, enabling ultracompact, multi-functional on-chip optical components such as filters and sensors.

Contribution

The work presents a new hybrid plasmonic ellipse resonator supporting independently tunable FPMs and WGMs, enabling dual-band slow light and multi-band filtering in a compact footprint.

Findings

Supports dual resonant modes (FPMs and WGMs)

Achieves dual-band slow light

Functions as multi-band color filter and sensor

Abstract

We propose a plasmonic ellipse resonator possessing hybrid modes based on metal-insulator-metal (MIM) waveguide system. Specially, this nanocavity has hybrid characteristic of rectangle and disk resonator, therefore supporting both Fabry-Perot modes (FPMs) and whispering-gallery modes (WGMs). Besides, by changing the length of major and minor radius of the ellipse, the resonant wavelengths of FPMs and WGMs can be independently tuned and close to each other, thus constructing a plasmon-induced transparency (PIT) - like spectrum profile. Benefitting from this, a dual-band slow light is achieved with one single resonator. Furthermore, this component can also act as a multi-band color filter and refractive index sensor. We believe such multi-mode resonator with ultra-small footprint will play an important role in more compact on-chip optical circuits in the future.