Probing the mechanisms of large Purcell enhancement in plasmonic nanoantennas

TitleProbing the mechanisms of large Purcell enhancement in plasmonic nanoantennas
Publication TypeJournal Article
Year of Publication2014
AuthorsG.M. Akselrod, C. Argyropoulos, T.B. Hoang, C. Ciracì, C. Fang, J. Huang, D.R. Smith, M.H. Mikkelsen
JournalNature Photonics
Volume8
Issue11
Pagination835 - 840
Date PublishedDec-10-2014
ISSN1749-4885
Abstract

o move nanophotonic devices such as lasers and single-photon sources into the practical realm, a challenging list of requirements must be met, including directional emission, room-temperature and broadband operation, high radiative quantum efficiency and a large spontaneous emission rate. To achieve these features simultaneously, a platform is needed for which the various decay channels of embedded emitters can be fully understood and controlled. Here, we show that all these device requirements can be satisfied by a film-coupled metal nanocube system with emitters embedded in the dielectric gap region. Fluorescence lifetime measurements on ensembles of emitters reveal spontaneous emission rate enhancements exceeding 1,000 while maintaining high quantum efficiency (>0.5) and directional emission (84% collection efficiency). Using angle-resolved fluorescence measurements, we independently determine the orientations of emission dipoles in the nanoscale gap. Incorporating this information with the three-dimensional spatial distribution of dipoles into full-wave simulations predicts time-resolved emission in excellent agreement with experiments.

DOI10.1038/nphoton.2014.228
Short TitleNature Photon