Dispersionless optical activity in metamaterials

Dispersionless optical activity in metamaterials

Metamaterials: optical activity without chirality.

We report that the classical phenomenon of optical activity, which is traditionally associated with chirality (helicity) of organic molecules, proteins, and inorganic structures, can be observed in artificial planar media which exhibit neither 3D nor 2D chirality. We observe the effect in the microwave and optical parts of the spectrum at oblique incidence to regular arrays of nonchiral subwave...

Pure nonlinear optical activity in metamaterials

We demonstrate a type of meta-atom for creating metamaterials with giant nonlinear optical activity but vanishing linear optical activity in a wide frequency range. Such properties are not found in any natural materials, and we call this regime as pure nonlinear optical activity. We further extend our design concept and show that the metamaterial can be tuned dynamically to exhibit either posit...

Broadband chiral metamaterials with large optical activity

Kirsty Hannam,1,* David A. Powell,1 Ilya V. Shadrivov,1 and Yuri S. Kivshar1,2 1Nonlinear Physics Center, Research School of Physics and Engineering, Australian National University, Canberra, Australian Capital Territory 0200, Australia 2National Research University of Information Technology, Mechanics and Optics, St. Petersburg 197101, Russia (Received 23 January 2014; revised manuscript recei...

Highly tunable optical activity in planar achiral terahertz metamaterials.

Using terahertz time domain spectroscopy we demonstrate tunable polarization rotation and circular dichroism in intrinsically non-chiral planar terahertz metamaterials without twofold rotational symmetry. The observed effect is due to extrinsic chirality arising from the mutual orientation of the metamaterial plane and the propagation direction of the incident terahertz wave.