Strong optical activity from twisted-cross photonic metamaterials.
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.
Decker
M
M
Institut für Angewandte Physik and DFG-Center for Functional Nanostructures (CFN), Universität Karlsruhe (TH),D-76128 Karlsruhe, Germany. manuel.decker@physik.uni-karlsruhe.de
Ruther
M
M
Kriegler
C E
CE
Zhou
J
J
Soukoulis
C M
CM
Linden
S
S
Wegener
M
M