Nondispersive optical activity of meshed helical 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...

Dispersionless optical activity in metamaterials

Locally Enhanced and Tunable Optical Chirality in Helical Metamaterials

We report on a numerical study of optical chirality. Intertwined gold helices illuminated with plane waves concentrate right and left circularly polarized electromagnetic field energy to sub-wavelength regions. These spots of enhanced chirality can be smoothly shifted in position and magnitude by varying illumination parameters, allowing for the control of light-matter interactions on a nanomet...

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...