These Are Not Your Girlfriend's Fishnets
The scientific breakthroughs came in the development of metamaterials -- composite materials with extraordinary capabilities to bend electromagnetic waves -- that can achieve a negative index of refraction at optical frequencies.
In one project, researchers stacked together alternating layers of silver and non-conducting magnesium fluoride and cut nanoscale-sized fishnet patterns into the layers to create a bulk optical metamaterial. At wavelengths as short as 1500 nanometers, the near-infrared light range, researchers measured a negative index of refraction. For a metamaterial to achieve negative refraction, its structural array must be smaller than the electromagnetic wavelength being used.
The fishnet material is strongly interacting nanocircuits that allow light to pass through the material and expend less energy moving through the metal layers, the scientists reported.
This is a schematic of the first 3-D "fishnet" metamaterials.