Plasmon-Modulated Photoluminescence of Single Gold Nanobeams
- Publication date
- 2015
- Publisher
Abstract
In
this work, we investigate the modulation of the photoluminescence
(PL) of a single Au nanobeam (NB) by the surface plasmons of a Ag
nanowire (NW) and the gap plasmons between the two nanostructures.
By changing the polarization of the laser that excites the nanostructure
and controlling the separation distance <i>d</i> between
the two nanostructures, we found that the transverse surface plasmon
resonance of the Ag NW enhanced the PL (at 520 nm) of the Au NB with
a maximum effect at <i>d</i> = 7 nm. The PL enhancement
(at 520 nm) was quenched and a new PL peak was observed at a longer
wavelength for <i>d</i> < 7 nm. The PL quenching effect
could be understood by the quadrupole-like plasmonic resonance between
the Ag NW and the Au NB and be qualitatively explained by the mode
dispersion as a function of <i>d</i> obtained using the
transfer matrix transmittance calculation. FDTD simulations show that
the new PL peak at a longer wavelength is caused by the waveguide-mode
gap plasmons between the Au NB and the Ag NW