Open AccessEdge scattering of surface plasmons excited by scanning tunneling microscopy
Author(s) -
Yang Zhang,
Élizabeth Boer-Duchemin,
Tao Wang,
Benoît Rogez,
G. Comtet,
Eric Le Moal,
Gérald Dujardin,
Andreas Hohenau,
Christian Gruber,
Joachim R. Krenn
Publication year - 2013
Publication title -
optics express
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.394
H-Index - 271
ISSN - 1094-4087
DOI - 10.1364/oe.21.013938
Subject(s) - surface plasmon , surface plasmon polariton , optics , plasmon , scattering , scanning tunneling microscope , light scattering , total internal reflection , materials science , localized surface plasmon , polariton , physics , condensed matter physics
The scattering of electrically excited surface plasmon polaritons (SPPs) into photons at the edges of gold metal stripes is investigated. The SPPs are locally generated by the inelastic tunneling current of a scanning tunneling microscope (STM). The majority of the collected light arising from the scattering of SPPs at the stripe edges is emitted in the forward direction and is collected at large angle (close to the air-glass critical angle, θ(c)). A much weaker isotropic component of the scattered light gives rise to an interference pattern in the Fourier plane images, demonstrating that plasmons may be scattered coherently. An analysis of the interference pattern as a function of excitation position on the stripe is used to determine a value of 1.42 ± 0.18 for the relative plasmon wave vector (kSPP/k0) of the corresponding SPPs. From these results, we interpret the directional, large angle (θ~θ(c)) scattering to be mainly from plasmons on the air-gold interface, and the diffuse scattering forming interference fringes to be dominantly from plasmons on the gold-substrate interface.