Thursday, August 18, 2011
Bending light the 'wrong' way: It was believed that these effects can only be achieved using so called "meta-materials". Such materials are constructed from small intricate structures, which diffract the light in special ways on a microscopic level. At the TU Vienna, scientists found out that with simple tricks even quite common metals such as cobalt or iron can exhibit a negative refractive index. "We place the metal in a strong magnetic field and irradiate it with light of precisely the correct wavelength", Andrei Pimenov explains. He uses microwave radiation, which can penetrate thin foils of metal. Due to magnetic resonance effects in the metal, the light is bent drastically at the surface. Within the metal, it turns into the other direction, as if there was a mirror inside the metal.