title: Strong optical activity from twisted-cross photonic metamaterials.
abstract: Following a recent theoretical suggestion and microwave experiments, we fabricate photonic metamaterials composed of pairs of twisted gold crosses using two successive electron-beam-lithography steps and intermediate planarization via a spin-on dielectric. The resulting two effective resonances of the coupled system lie in the 1-2 microm wavelength regime and exhibit pronounced circular dichroism, while the circular polarization conversion is very small. In between the two resonances, we find a fairly broad spectral regime with strong optical activity, i.e., with a pure rotation of incident linear polarization. The measured optical transmittance spectra agree well with theory.
authors.affiliation: Institut für Angewandte Physik and DFG-Center for Functional Nanostructures (CFN), Universität Karlsruhe (TH),D-76128 Karlsruhe, Germany. manuel.decker@physik.uni-karlsruhe.de
authors.forename: M
authors.initials: M
authors.lastname: Decker
authors.forename: M
authors.initials: M
authors.lastname: Ruther
authors.forename: C E
authors.initials: CE
authors.lastname: Kriegler
authors.forename: J
authors.initials: J
authors.lastname: Zhou
authors.forename: C M
authors.initials: CM
authors.lastname: Soukoulis
authors.forename: S
authors.initials: S
authors.lastname: Linden
authors.forename: M
authors.initials: M
authors.lastname: Wegener