Strong optical activity from twisted-cross photonic metamaterials

  • Author: M. Decker, M. Ruther, C.E. Kriegler, J. Zhou, C.M. Soukoulis, S. Linden, and M. Wegener
  • Source: Opt. Lett. 34, 2501 (2009)
  • Date: 13.8.2009

  • 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 μm 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.
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