Negative Index Made Easy

Abstract

MATERIALS SCIENCE The realization of designer materials, or metamaterials, in which the electrical permittivity and magnetic permeability can be made negative simultaneously has generated much interest, primarily due to theoretical proposals for remarkable applications such as perfect lenses and, most recently, the ability to hide, or cloak, objects from electromagnetic radiation. After the initial demonstration in the microwave regime, much of the experimental effort in metamaterial design has focused on pushing the response of these materials toward shorter wavelengths. However, the design of choice, a split ring resonator coupled to a metal wire, is somewhat limited when it comes to size reduction, and other approaches are being pursued. Chettiar et al. propose the use of a simpler structure to achieve negative refraction: a pair of metallic nanostrips separated by a thin dielectric layer, easily fabricated with existing deposition and lithographic technology down to feature sizes in the 10- to 100-nm range. Their simulations show that coupling such pairs of nanostrips to continuous metal films should provide a negative refractive index in the optical and infrared regimes. — ISO Opt. Express 14 , 7872 (2006).