Infrared cloaking based on the electric response of split ring resonators

Electromagnetic cloak was recently demonstrated in the microwave domain using a metamaterial structure made of metallic split ring resonators (SRR) arranged in a cylindrical geometry. The SRRs were designed to provide a magnetic response that varied in an appropriate manner with the radial coordinate. In the present work, we propose an electromagnetic cloak, which exploits the electric response of gold SRRs instead of their magnetic response. Numerical simulations performed at infrared frequencies (similar to 100 THz) reveal low loss and weak impedance mismatch, thereby proving the interest in using SRRs as universal atoms in the design of metamaterials. We also show that SRRs can be ultimately replaced by simple cut wires for the construction of approximate electromagnetic cloaks whose dielectric permittivity is the only parameter varying with space coordinates. (C) 2008 Optical Society of America.