title: Second-harmonic optical spectroscopy on split-ring-resonator arrays.
abstract: Previous second-harmonic-generation experiments on metallic split-ring-resonator arrays have been performed at fixed fundamental laser center frequency. Here, we perform nonlinear optical spectroscopy on a first set of samples, revealing pronounced resonances. Furthermore, to clarify the role of higher-order split-ring resonances, we perform additional experiments on a second set of samples in which the fundamental split-ring-resonator resonance frequencies are lithographically tuned, whereas the higher-order resonances are fixed. We find that the higher-order resonances merely reabsorb the second-harmonic generation, revealing the fundamental split-ring resonance as the nonlinear source.
authors.affiliation: Institut für Angewandte Physik, Karlsruhe Institute of Technology (KIT), D-76128 Karlsruhe, Germany. fabian.niesler@kit.edu
authors.forename: Fabian B P
authors.initials: FB
authors.lastname: Niesler
authors.forename: Nils
authors.initials: N
authors.lastname: Feth
authors.forename: Stefan
authors.initials: S
authors.lastname: Linden
authors.forename: Martin
authors.initials: M
authors.lastname: Wegener