Eur. Phys. J. B 81, 85-93 (2011)
https://doi.org/10.1140/epjb/e2011-10781-2

Controlling the optical spectra of gold nano-islands by changing the aspect ratio and the inter-island distance: theory and experiment

¹ Department of Physics, Bar-Ilan University, 52900 Ramat-Gan, Israel
² Raymond and Beverly Sackler School of Physics and Astronomy, Faculty of Exact Sciences, Tel Aviv University, 69978 Tel Aviv, Israel
³ Institute for Theoretical and Applied Electromagnetics, Moscow, 125412 Izhorskaya 13, Russia

Corresponding author: ^a strelnik@biu.ac.il

Received: 13 October 2010
Revised: 15 March 2011
Published online: 4 May 2011

Abstract

The extinction spectrum of a dielectric film with periodic array of metallic islands of different shapes and different mutual distances was studied both theoretically and experimentally. It is shown, analytically, numerically and experimentally, that the positions of the surface plasmon resonances depend on the nano-structural details. We propose two ways of controlling plasmon resonance frequency: changing the aspect ratio of the elliptical (or rectangular) islands and changing their mutual distances. A new analytical asymptotic approach for calculating the optical properties of such plasmonic systems is developed. The results of our analytical and numerical studies are in good qualitative agreement with experiment.