Optically isotropic negative index of refraction metemeterial

We report a metamaterial with optically isotropic negative refraction index, n, and small loss factor, k - vertical bar Im (n)/Re (n)vertical bar <= 0.4, that occurs near the visible/UV line: The metamaterial presented consists of two media. One medium (randomly distributed gold spherical nanoparticles with Drude-like permittivity, in free space) ensures negative permittivity, and another medium (spherical SiC nanoparticles) ensures negative permeability via the Mie resonance within the same frequency range. We have found, self-consistently; in the framework of both the effective medium approach and rigorous first-principles based Finite Difference Time Domain (FDTD) simulations, that the metamaterial exhibits negative refraction index behavior. This result stands for both the random distribution of the SiC particles, and the regular simple-cubic lattice of the same particles. (c) 2008 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.