First practical metamaterials with negative index of refraction
Researchers in the UK and Spain have successfully created the first practical metamaterial sample that interacts with visible light. Metamaterials are a class of materials that, in the optical terms, interact with light in unusual and classically impossible ways. This particular metamaterial, assembled by a group led by Carlos Garcia-Meca, consists of 15- to 35-nanometer thick layers of silver and a specific type of glass. Exploiting the unique optical properties of silver, the researchers have created a material with a negative index of refraction. Materials with a negative index of refraction have typically been impermeable to visible light, but this new material could open up a whole range of potential uses that exploit these properties. For one, a negative index of refraction material would allow for the creation of super-lenses, or lenses that go beyond the diffraction limit -- an inherent limitation of the smallest objects resolution available to typical optical devices.