Forward and backward unidirectional scattering from plasmonic coupled wires.


Journal Article

We analyze the resonant electromagnetic response of sub-wavelength plasmonic dimers formed by two silver strips separated by a thin dielectric spacer and embedded in a uniform dielectric media. We demonstrate that the off-resonant electric and resonant, geometric shape-leveraged, magnetic polarizabilities of the dimer element can be designed to have close absolute values in a certain spectral range, resulting in a predominantly unidirectional scattering of the incident field due to pronounced magneto-electric interference. Switching between forward and backward directionality can be achieved with a single element by changing the excitation wavelength, with the scattering direction defined by the relative phases of the polarizabilities. We extend the analysis to some periodic configurations, including the specific case of a perforated metal film, and discuss the differences between the observed unidirectional scattering and the extraordinary transmission effect. The unidirectional response can be preserved and enhanced with periodic arrays of dimers and can find applications in nanoantenna devices, integrated optic circuits, sensors with nanoparticles, photovoltaic systems, or perfect absorbers; while the option of switching between forward and backward unidirectional scattering may create interesting possibilities for manipulating optical pressure forces.

Full Text

Duke Authors

Cited Authors

  • Poutrina, E; Rose, A; Brown, D; Urbas, A; Smith, DR

Published Date

  • December 2013

Published In

Volume / Issue

  • 21 / 25

Start / End Page

  • 31138 - 31154

PubMed ID

  • 24514688

Pubmed Central ID

  • 24514688

Electronic International Standard Serial Number (EISSN)

  • 1094-4087

International Standard Serial Number (ISSN)

  • 1094-4087

Digital Object Identifier (DOI)

  • 10.1364/oe.21.031138


  • eng