Enhanced Purcell factor for nanoantennas supporting interfering resonances

TL;DR

This paper investigates how coupled resonances and quasi-BICs in dielectric nanoantennas can significantly enhance the Purcell factor, with numerical analysis showing substantial boosts in emission rates due to strong resonance coupling.

Contribution

It introduces a detailed numerical analysis of interfering resonances and quasi-BICs in dielectric nanoantennas, highlighting their role in enhancing the Purcell effect.

Findings

Purcell factor can be substantially increased with strong resonance coupling

Interfering resonances influence radiation patterns and emission rates

Quasi-BIC regime offers significant Purcell enhancement

Abstract

We study the effect of coupled resonances and quasi-bound states in the continuum (quasi-BICs) on the Purcell factor in dielectric resonant nanoantennas. We analyze numerically interfering resonances in a nanodisk with and without a substrate when the modes are coupled to an emitter localized inside the nanodisk, and we quantify the modal contributions to the Purcell factor also reconstructing the radiation patterns of the resonant system. It is revealed that the Purcell effect can be boosted substantially for a strong coupling of resonances in the quasi-BIC regime.