Bianisotropy and spatial dispersion in highly anisotropic near-infrared resonator arrays.

We measure, simulate, and analyze the optical transmission through arrays of Ag nanorod pairs and U-shaped nanostructures as a function of polarization and angle of incidence. The bianisotropic nature of the metamaterials is exhibited in data and in simulations, and we argue that the electric field rather than the magnetic field excites the low frequency "magnetic" mode. We also observe spatial dispersion in the form of frequency shifts as a function of incident angle which we attribute to coupling effects between neighboring structures. A simple model based upon coupled electromagnetic dipoles is found to provide a qualitative description for the main features observed in the spectra.