Experimental investigation of a metamaterial omnidirectional reflector

We demonstrate experimentally the existence of an omnidirectional reflection band of a two-dimensional metamaterial structure consisting of split ring resonators and thin conducting wires. Experimental angular reflectance data agree reasonably well with simulations using model dispersion relations for the effective dielectric permittivity and magnetic permeability that were fitted to the experimentally retrieved material parameters. The tunability of the reflection bandwidth is demonstrated by changing the effective electric plasma frequency. These findings are also relevant to optical frequencies where similar metamaterial composites have been fabricated. (C) 2008 American Institute of Physics.