@article{7e982c678c1e4482a706499585c451f0,
title = "Photoelectron imaging of modal interference in plasmonic whispering gallery cavities",
abstract = "We use three-photon photoemission electron microscopy (PEEM) to investigate the interference of coherently excited dipolar and quadrupolar resonant modes of plasmonic whispering gallery resonators formed by circular grooves patterned into a flat Au surface. Optical scattering and cathodoluminescence spectroscopy are used to characterize the cavity resonance spectra for a wide range of cavity radii and groove depths. Using PEEM, we directly resolve the interference between the modal field distribution of dipolar and quadrupolar modes that are coherently excited at λ = 795 nm under oblique incidence. Characteristic asymmetries in the photoelectron images for both TM and TE excitation are a direct consequence of the coherent excitation of the resonant modes.",
author = "Pascal Melchior and Deirdre Kilbane and Vesseur, {Ernst Jan} and Albert Polman and Martin Aeschlimann",
note = "Funding Information: We gratefully acknowledge discussions with Toon Coenen. This work is supported by the Deutsche Forschungsgesellschaft (DFG) within the Research Focus Program ?Ultrafast Nano- Optics? (SPP 1391). The Dutch part of this work is part of the research program of the Foundation for Fundamental Research on Matter (FOM) which is financially supported by the Netherlands Organisation for Scientific Research (NWO). This research is also supported by the European Research Counsel. DK acknowledges funding from the Irish Research Council and the Marie Curie Actions ELEVATE fellowship. Publisher Copyright: {\textcopyright} 2015 Optical Society of America.",
year = "2015",
month = dec,
day = "14",
doi = "10.1364/OE.23.031619",
language = "English",
volume = "23",
pages = "31619--31626",
journal = "Optics Express",
issn = "1094-4087",
publisher = "The Optical Society",
number = "25",
}