Abstract
An effective-medium theory (EMT) is developed to predict the effective permittivity ε eff of dense random dispersions of high optical-conductivity metals such as Ag, Au, and Cu. Dependence of εeff on the volume fraction ø, a microstructure parameter-related to the static structure factor and particle radius a, is studied. In the electrostatic limit, the upper and lower bounds of k correspond to Maxwell-Garnett and Bruggeman EMTs, respectively. Finite size effects are significant when jβ2(ka/n)3 becomes O(1), where β, k, and n denote the nanoparticle polarizability, wavenumber, and matrix refractive index, respectively. The coupling between the particle and effective medium results in a red-shift in the resonance peak, a nonlinear dependence of εeff on ø, and Fano resonance in εeff .
Original language | English (US) |
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Pages (from-to) | 1443-1455 |
Number of pages | 13 |
Journal | Journal of the Optical Society of America B: Optical Physics |
Volume | 29 |
Issue number | 6 |
DOIs | |
State | Published - Jun 2012 |
ASJC Scopus subject areas
- Statistical and Nonlinear Physics
- Atomic and Molecular Physics, and Optics