title: Plasmonic modes of annular nanoresonators imaged by spectrally resolved cathodoluminescence.
abstract: We report the observation of plasmonic modes of annular resonators in nanofabricated Ag and Au surfaces that are imaged by spectrally resolved cathodoluminescence. A highly focused 30 keV electron beam is used to excite localized surface plasmons that couple to collective resonant modes of the nanoresonators. We demonstrate unprecedented resolution of plasmonic mode excitation and by combining these observations with full-field simulations find that cathodoluminescence in plasmonic nanostructures is most efficiently excited at positions corresponding to antinodes in the modal electric field intensity.
authors.affiliation: Thomas J Watson Laboratory of Applied Physics, California Institute of Technology, Pasadena, CA 91125, USA. carrie.hofmann@caltech.edu
authors.forename: Carrie E
authors.initials: CE
authors.lastname: Hofmann
authors.forename: Ernst Jan R
authors.initials: EJ
authors.lastname: Vesseur
authors.forename: Luke A
authors.initials: LA
authors.lastname: Sweatlock
authors.forename: Henri J
authors.initials: HJ
authors.lastname: Lezec
authors.forename: F Javier
authors.initials: FJ
authors.lastname: García de Abajo
authors.forename: Albert
authors.initials: A
authors.lastname: Polman
authors.forename: Harry A
authors.initials: HA
authors.lastname: Atwater
mesh_terms: D003198:Computer Simulation; D004566:Electrodes; D006046:Gold / Q000737:chemistry*; D007091:Image Processing, Computer-Assisted; D049449:Luminescence; D036103:Nanotechnology; D043942:Nanotubes; D012834:Silver / Q000737:chemistry*; D020349:Surface Plasmon Resonance
chemical_list: D012834:Silver; D006046:Gold