Imaging the hidden modes of ultrathin plasmonic strip antennas by cathodoluminescence.

Citation data:

Nano letters, ISSN: 1530-6992, Vol: 11, Issue: 10, Page: 4265-9

Publication Year:
2011
Usage 46
Abstract Views 46
Captures 75
Readers 74
Exports-Saves 1
Mentions 1
References 1
Citations 39
Citation Indexes 39
Repository URL:
http://hdl.handle.net/10754/598558
PMID:
21879729
DOI:
10.1021/nl202256k
Author(s):
Barnard, Edward S.; Coenen, Toon; Vesseur, Ernst Jan R.; Polman, Albert; Brongersma, Mark L.
Publisher(s):
American Chemical Society (ACS)
Tags:
Chemical Engineering; Chemistry; Materials Science; Physics and Astronomy; Engineering; antenna; cathodoluminescence; LDOS; quantum emitter; Surface plasmon polariton
article description
We perform spectrally resolved cathodoluminescence (CL) imaging nanoscopy using a 30 keV electron beam to identify the resonant modes of an ultrathin (20 nm), laterally tapered plasmonic Ag nanostrip antenna. We resolve with deep-subwavelength resolution four antenna resonances (resonance orders m = 2-5) that are ascribed to surface plasmon polariton standing waves that are confined on the strip. We map the local density of states on the strip surface and show that it has contributions from symmetric and antisymmetric surface plasmon polariton modes, each with a very different mode index. This work illustrates the power of CL experiments that can visualize hidden modes that for symmetry reasons have been elusive in optical light scattering experiments.