Spectroscopic ellipsometry of split ring resonators at infrared frequencies

Using spectroscopic ellipsometry, we have determined the plasmonic resonances of split-ring resonator arrays. The features in the ellipsometric spectra were explained by the analysis of calculated polarized complex reflection spectra. The calculated near-field and current distribution revealed the nature of the resonances. The positions of Rayleigh's anomalies are calculated and marked in the spectra. We have also shown that oblique incidence enables excitation of plasmonic modes that are not possible to excite at normal incidence. (C) 2012 American Institute of Physics. [http://dx.doi.org/10.1063/1.4703936]