Table of Contents Author Guidelines Submit a Manuscript
International Journal of Optics
Volume 2012, Article ID 532576, 8 pages
http://dx.doi.org/10.1155/2012/532576
Research Article

Digital Heterodyne Holography Reveals the Non-Quasi-Static Scattering Behaviour of Transversally Coupled Nanodisk Pairs

1Institut Langevin, ESPCI ParisTech, CNRS UMR 7587, 10 rue Vauquelin, 75231 Paris Cedex 05, France
2Fondation Pierre-Gilles de Gennes pour la Recherche, 29 rue d'Ulm, 75005 Paris, France
3Institut Fresnel, CNRS UMR 7249, Aix-Marseille Université, Ecole Centrale Marseille, Domaine Universitaire de Saint Jérôme, 13397 Marseille, France
4Laboratoire de Photonique et de Nanostructures (LPN-CNRS UPR 20), route de Nozay, 91460 Marcoussis, France

Received 27 October 2011; Accepted 9 December 2011

Academic Editor: Alexandre Bouhelier

Copyright © 2012 Sarah Y. Suck et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

We reconstruct the full three-dimensional scattering pattern of longitudinal and transverse modes in pairs of coupled gold nanodisks using digital heterodyne holography. Near-field simulations prove that, in our experimental conditions, the induced dipoles in the longitudinal mode are in phase while they are nearly in opposite phase for the transverse mode. The scattering efficiency of the two modes is of the same order of magnitude, which goes against the common belief that antisymmetric transverse modes are “dark.” The analysis of the reconstructed hologram in the Fourier plane allows us to estimate the angular scattering pattern for both excited modes. In particular, the antisymmetric transverse mode scatters light mostly into one half-plane, demonstrating that the quasi-static approximation breaks down in nanodisk pairs even for an interparticle distance lower than .