title: Optical response of supported gold nanodisks.
abstract: It is shown that the ellipsometric spectra of short range ordered planar arrays of gold nanodisks supported on glass substrates can be described by modeling the nanostructured arrays as uniaxial homogeneous layers with dielectric functions of the Lorentz type. However, appreciable deviations from experimental data are observed in calculated spectra of irradiance measurements. A qualitative and quantitative description of all measured spectra is obtained with a uniaxial effective medium dielectric function in which the nanodisks are modeled as oblate spheroids. Dynamic depolarization factors in the long-wavelength approximation and interaction with the substrate are considered. Similar results are obtained calculating the optical spectra using the island-film theory. Nevertheless, a small in-plane anisotropy and quadrupolar coupling effects reveal a very complex optical response of the nanostructured arrays.
authors.affiliation: Cinvestav-IPN, Unidad Querétaro, Libramiento Norponiente 2000, 76230 Querétaro, Mexico. amendoza@qro.cinvestav.mx
authors.forename: A
authors.initials: A
authors.lastname: Mendoza-Galván
authors.forename: K
authors.initials: K
authors.lastname: Järrendahl
authors.forename: A
authors.initials: A
authors.lastname: Dmitriev
authors.forename: T
authors.initials: T
authors.lastname: Pakizeh
authors.forename: M
authors.initials: M
authors.lastname: Käll
authors.forename: H
authors.initials: H
authors.lastname: Arwin
mesh_terms: D016880:Anisotropy; D006046:Gold / Q000737:chemistry*; D008420:Manufactured Materials; D053768:Metal Nanoparticles / Q000737:chemistry*; D008962:Models, Theoretical; D036103:Nanotechnology / Q000379:methods*; D011827:Radiation; D020349:Surface Plasmon Resonance / Q000379:methods*
chemical_list: D006046:Gold