Superemitters in Hybrid Photonic Systems: A Simple Lumping Rule for the Local Density of Optical States and its Break-Down at the Unitary Limit

TL;DR

This paper explores how complex photonic environments influence the enhancement of spontaneous emission rates by optical antennas, revealing that near the unitary limit, environmental LDOS can significantly diminish antenna performance.

Contribution

It introduces a simple lumping rule for local density of optical states in hybrid systems and shows its breakdown near the unitary scattering limit.

Findings

Enhanced LDOS boosts weakly scattering antennas

Near the unitary limit, environmental LDOS reduces antenna enhancement

Multiple scattering enables LDOS engineering in hybrid systems

Abstract

We theoretically investigate how the enhancement of the radiative decay rate of a spontaneous emitter provided by coupling to an optical antenna is modified when this "superemitter" is introduced into a complex photonic environment that provides an enhanced local density of optical states (LDOS) itself, such as a microcavity. We show that photonic environments with increased LDOS further boost the performance of antennas that scatter weakly, i.e. that are far from the unitary limit, for which a simple multiplicative LDOS lumping rule holds. In contrast, enhancements provided by antennas close to the unitary limit, i.e. antennas close to the limit of maximally possible scattering strength, are strongly reduced by an enhanced LDOS of the environment. Thus, we identify multiple scattering in hybrid photonic systems as a powerful mechanism for LDOS engineering.