Magnetic hyperbolic optical metamaterials UC （磁双曲光学超材料加州大学）.pdf

ARTICLE Received 28 Jul 2015 | Accepted 11 Mar 2016 | Published 13 Apr 2016 DOI: 10.1038/ncomms11329 OPEN Magnetic hyperbolic optical metamaterials 1 2 1,3 2 1 Sergey S. Kruk , Zi Jing Wong , Ekaterina Pshenay-Severin , Kevin O’Brien , Dragomir N. Neshev , Yuri S. Kivshar1 Xiang Zhang2,4,5 Strongly anisotropic media where the principal components of electric permittivity or magnetic permeability tensors have opposite signs are termed as hyperbolic media. Such media support propagating electromagnetic waves with extremely large wave vectors exhibiting unique optical properties. However, in all artificial and natural optical materials studied to date, the hyperbolic dispersion originates solely from the electric response. This restricts material functionality to one polarization of light and inhibits free-space impedance matching. Such restrictions can be overcome in media having components of opposite signs for both electric and magnetic tensors. Here we present the experimental demonstration of the magnetic hyperbolic dispersion in three-dimensional metamaterials. We measure metamaterial isofrequency contours and reveal the topological phase transition between the elliptic and hyperbolic dispersion. In the hyperbolic regime, we demonstrate the strong enhancement of thermal emission, which becomes directional, coherent and polarized. Our findings show the possibilities for realizing efficient impedance-matched hyperbolic media for unpolarized light. 1 Nonlinear Physics Center and Center for Ultrahigh Bandwidth Devices for Optical Systems (CUDOS), Research School of Physics and Engineering, The Australian National University, Canberra, Australian Capital Territor