Emission redistribution from a quantum dot-bowtie nanoantenna

TL;DR

This study investigates how a quantum dot coupled to a plasmonic nanoantenna redistributes emission intensity without significant Purcell enhancement, combining experimental measurements with simulations to understand light-matter interactions.

Contribution

It provides the first combined experimental and simulation analysis of emission redistribution in a quantum dot-plasmonic antenna system without notable Purcell effect.

Findings

Emission intensity increases by approximately 2.4 times due to far-field redistribution.

No significant Purcell enhancement observed; exciton lifetimes remain around 0.5 ns.

Numerical simulations suggest Purcell effects are less than 2 times for separations over 25 nm.

Abstract

We present a combined experimental and simulation study of a single self-assembled InGaAs quantum dot coupled to a nearby ($\sim 25nm$) plasmonic antenna. Micro-photoluminescence spectroscopy shows a $\sim 2.4\times$ increase of intensity, which is attributed to spatial far-field redistribution of the emission from the quantum dot-antenna system. Power-dependent studies show similar saturation powers of $2.5\mu W$ for both coupled and uncoupled quantum dot emission in polarization-resolved measurements. Moreover, time-resolved spectroscopy reveals the absence of Purcell-enhancement of the quantum dot coupled to the antenna as compared to an uncoupled dot, yielding comparable exciton lifetimes of $\tau\sim0.5ns$. This observation is supported by numerical simulations, suggesting only minor Purcell-effects of $<2\times$ for emitter-antenna separations $>25nm$. The observed increased emission from a coupled quantum dot-plasmonic antenna system is found to be in good qualitative agreement with numerical simulations and will lead to a better understanding of light-matter-coupling in such novel semiconductor-plasmonic hybrid systems