A copper negative index metamaterial in the visible / near-infrared. (arXiv:1107.4489v1 [physics.optics])

A copper negative index metamaterial in the visible / near-infrared. (arXiv:1107.4489v1 [physics.optics]): "
We propose a design for a novel plasmonic copper metamaterial with an index
of refraction equal to -1 at an operating wavelength of 700 nm. Using numerical
simulations, we demonstrate negative refraction by a copper metamaterial prism,
and perform a parameter extraction technique to verify the sign of the
effective index of refraction, electric permittivity and magnetic permeability.
Our proposed design has a figure of merit comparable to similar silver-based
metamaterials operating in the visible/near-infrared range. These findings have
implications for the design of low cost plasmonic devices and negative-index
metamaterials in the visible / near-infrared.