Numerical investigation of negative refractive index metamaterials at infrared and optical frequencies

An analysis of the transmission properties of a slab of metallic split-ring resonators at near infrared and optical frequencies is presented. We focus on the influence of the parameters characterizing the intrinsic frequency dispersion of the metallic rings on the physical properties of recently introduced materials that exhibit a negative refractive index. It is demonstrated that, when a mesh of thin metallic wires is added, at the resonant frequency omega(0) similar to 150 THz the refractive index of the resulting metamaterial is negative within a frequency hand Deltaomega similar to 50 THz. The numerical analysis is performed using the transfer matrix formalism. (C) 2003 Published by Elsevier B.V.