Open AccessCurvature-induced geometric momenta: the origin of waveguide dispersion of surface plasmons on metallic wires
Author(s) -
Ron Spittel,
Patrick Uebel,
Hartmut Bartelt,
Markus A. Schmidt
Publication year - 2015
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.23.012174
Subject(s) - surface plasmon polariton , curvature , dispersion (optics) , surface plasmon , optics , waveguide , physics , planar , plasmon , phase velocity , helicity , momentum (technical analysis) , materials science , condensed matter physics , geometry , quantum mechanics , mathematics , computer graphics (images) , finance , computer science , economics
We show that the propagation of surface plasmon polaritons (SPPs) on metallic wires is governed by two solely curvature-induced geometric momenta, leading to a significant modification of the waveguide dispersion, i.e. a change of their phase velocity. By quantifying the azimuthal momentum and superimposing two planar SPPs of opposite helicity, we find an analytic expression for the dispersion of guided SPPs. This expression shows excellent agreement with numerical simulations and allows explaining fundamental SPP properties such as waveguide dispersion.