Fluorescence enhancement and strong-coupling in faceted plasmonic nanocavities
Blackett Laboratory, Prince Consort Road, Imperial College London,
SW7 2AZ, UK
2 School of Physics and Astronomy, University of Birmingham, Edgbaston, Birmingham B15 2TT, UK
3 Cavendish Laboratory, University of Cambridge, Cambridge CB3 0HE, UK
* e-mail: firstname.lastname@example.org
Accepted: 15 February 2018
Published online: 4 June 2018
Emission properties of a quantum emitter can be significantly modified inside nanometre-sized gaps between two plasmonic nanostructures. This forms a nanoscopic optical cavity which allows single-molecule detection and single-molecule strong-coupling at room temperature. However, plasmonic resonances of a plasmonic nanocavity are highly sensitive to the exact gap morphology. In this article, we shed light on the effect of gap morphology on the plasmonic resonances of a faceted nanoparticle-on-mirror (NPoM) nanocavity and their interaction with quantum emitters. We find that with increasing facet width the NPoM nanocavity provides weaker field enhancement and thus less coupling strength to a single quantum emitter since the effective mode volume increases with the facet width. However, if multiple emitters are present, a faceted NPoM nanocavity is capable of accommodating a larger number of emitters, and hence the overall coupling strength is larger due to the collective and coherent energy exchange from all the emitters. Our findings pave the way to more efficient designs of nanocavities for room-temperature light-matter strong-coupling, thus providing a big step forward to a non-cryogenic platform for quantum technologies.
Key words: Nanoplasmonics / Nanophotonics / Light-matter Strong-coupling / Fluorescence Enhancement / Quenching
© N. Kongsuwan et al., published by EDP Sciences, 2018
This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.