Open AccessSurface plasmon polariton beams from an electrically excited plasmonic crystal
Author(s) -
Damien Canneson,
Eric Le Moal,
Shuiyan Cao,
Xavier Quélin,
H. Dallaporta,
Gérald Dujardin,
Élizabeth Boer-Duchemin
Publication year - 2016
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.24.026186
Subject(s) - plasmon , surface plasmon polariton , surface plasmon , optics , materials science , optoelectronics , scattering , finite difference time domain method , crystal (programming language) , physics , computer science , programming language
Surface plasmon polariton (SPP) beams with an in-plane angular spread of 8° are produced by electrically exciting a 2D plasmonic crystal using a scanning tunneling microscope (STM). The plasmonic crystal consists of a gold nanoparticle (NP) array on a thin gold film on a glass substrate and it is the inelastic tunnel electrons (IET) from the STM that provide a localized and spectrally broadband SPP source. Surface waves on the gold film are shown to be essential for the coupling of the local, electrical excitation to the extended NP array, thus leading to the creation of SPP beams. A simple model of the scattering of SPPs by the array is used to explain the origin and direction of the generated SPP beams under certain conditions. In order to take into account the broadband spectrum of the source, calculations realized using finite-difference time-domain (FDTD) methods are obtained, showing that bandgaps for SPP propagation exist for certain wavelengths and indicating how changing the pitch of the NP array may enhance the SPP beaming effect.