Manipulating the Quasi-Normal Modes of Radially Symmetric Resonators

TL;DR

This paper introduces two methods for precisely controlling the resonance properties of radially symmetric resonators, enabling tailored frequency, linewidth, and mode characteristics for advanced photonic applications.

Contribution

It presents a novel eigenvalue formulation and a quasi-normal mode perturbation approach for designing radially graded resonators with specific resonance features.

Findings

Effective control of resonance frequency and linewidth achieved

Design of radially graded structures with targeted resonances

Enhanced ability to tailor multipolar resonant modes

Abstract

We derive two methods for simultaneously controlling the resonance frequency, linewidth and multipolar nature of the resonances of radially symmetric structures. Firstly, we formulate an eigenvalue problem for a global shift in the permittivity of the structure to place a resonance at a particular complex frequency. Next, we employ quasi-normal mode perturbation theory to design radially graded structures with resonances at desired frequencies.