Tunable plasmonic dichroism of Au nanoparticles self-aligned on rippled Al₂O₃ thin films

¹ Institut Pprime, Département Physique et Mécanique des Matériaux, UPR 3346 CNRS, Université de Poitiers, SP2MI, Téléport 2 - Bvd. M. et P. Curie, BP 30179, 86962 Futuroscope Chasseneuil Cedex, France, EU
² Synchrotron SOLEIL, L'Orme des Merisiers Saint-Aubin - BP 48, 91192 Gif-sur-Yvette, France, EU

^a david.babonneau@univ-poitiers.fr

Received: 9 December 2010
Accepted: 14 January 2011

Abstract

The self-alignment and optical dichroism of Au nanoparticle chains grown by glancing incidence deposition on rippled Al₂O₃ thin films is investigated. Although the nucleation of the nanoparticles is almost isotropic, their growth is strongly anisotropic resulting in a sharp dependence of their optical transmittance on the orientation of the polarization of the incident light. We show that both the frequency and the spectral width of the transverse and longitudinal surface plasmon resonances can be easily tuned by varying the amount of deposited metal. Such nanostructured materials open perspectives for the development of plasmonic devices endowed with tunable optical dichroism both in the visible and the near infrared regimes.