Anomalous birefringence and enhanced magneto-optical effects in epsilon-near-zero metamaterials based on nanorods' arrays.

Hyperbolic metamaterials based on the ordered arrays of metal nanorods in a dielectric media are of great interest owing to new optical effects appearing in such artificial media. Here we study the effects in the polarization state of light passing through a nanocomposite material consisting of Au nanorods in porous alumina and a similar structure supplemented by a nanolayer of ferromagnetic nickel. We demonstrate that close to the epsilon-near-zero dispersion point, under the transition to the hyperbolic dispersion region, the nanocomposites reveal anomalously high modulation of the polarization state of light, which appears as polarization plane rotation and ellipticity changes of probing radiation with a zero ellipticity.

Tuning the Optical Properties of Hyperbolic Metamaterials by Controlling the Volume Fraction of Metallic Nanorods.

Porous films of anodic aluminum oxide are widely used as templates for the electrochemical preparation of functional nanocomposites containing ordered arrays of anisotropic nanostructures. In these structures, the volume fraction of the inclusion phase, which strongly determines the functional properties of the nanocomposite, is equal to the porosity of the initial template. For the range of systems, the most pronounced effects and the best functional properties are expected when the volume fraction of metal is less than 10%, whereas the porosity of anodic aluminum oxide typically exceeds this value.

Magneto-optical effects in hyperbolic metamaterials.

Highly anisotropic metal-dielectric structures reveal unique dispersion properties providing new optical effects. Here we study experimentally linear optical and magneto-optical response of arrays of plasmonic gold nanorods and similar structures complemented by a thin nickel film. We show that both types of structures reveal distinct optical features expected for hyperbolic media and associated with the epsilon-near-zero (ENZ) and epsilon-near-pole (ENP) points.