Table of Contents
ISRN Nanotechnology
Volume 2011 (2011), Article ID 487646, 9 pages
http://dx.doi.org/10.5402/2011/487646
Research Article

Nonlinear Optical Properties of Spheroidal Metallic Inclusions in a Dielectric Medium

1Département de Mathématiques et de Statistique, Université de Moncton, Moncton, NB, Canada E1A 3E9
2Department of Physics, Concordia University, 7141 Sherbrooke West, SP 367.03, Montréal, QC, Canada H4B 1R6

Received 23 August 2011; Accepted 27 September 2011

Academic Editors: B. Coasne and A. Ryasnyanskiy

Copyright © 2011 Bernard de Dormale and Vo-Van Truong. 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

A model for linear and nonlinear optical properties of a composite material consisting of spheroidal metal inclusions embedded in a host medium has been formulated using an effective medium approach. Both aligned and randomly oriented spheroids have been considered, and the results obtained showed a considerable difference between the two situations. Numerical calculations for metallic Au inclusions in a glass matrix have shown that the linear absorption in the case of aligned spheroids with their symmetry axis parallel to the z-axis is largely dependent on the depolarization factor, exhibiting an absorption in the vicinity of 500 nm when the depolarization factor in the direction parallel to the rotational symmetry axis is small. This structure shifts progressively to higher wavelengths when this depolarization factor is increased. In the case of randomly oriented spheroids, contributions from the different particle depolarization factors are present and prominent structures in the linear absorption appear in the long wavelength region, beyond 700 nm. Nonlinear optical properties for both aligned and randomly oriented spheroids also show a strong dependence on the depolarization factor and significant enhancements of these properties can be observed, suggesting possible tailoring of composite properties for various applications.