Scientists of the Moscow Physics and Technology Institute and the Landau Pure Physics Institute of RAS have developed a two-dimensional metamaterial of silver elements, which refracts light in a special way.

It is the so-called metasurface, a thin film made of separate elements that make it possible to manipulate light. The work principle of a metasurface is based on diffraction phenomenon – the waves’ ability to envelop obstacles. An elementary cell of the diffraction lattice suggested by Russian physics is a pair of close located silver cylinders with the radius of about 100 nanometers. Such a structure works in an optical area, whereas most of its analogs are of more complicated geometry and work with microwave radiation only.

Effective interaction of metal cylinder pairs with light happens thanks to the plasmon resonance effect. Light is absorbed with metal bars, thus forcing the electrons in metal to oscillate, and reradiates.

The results of computer modeling showed high efficiency of the material for light with the wavelength of 400-500 nanometers (violet, blue and light blue). The efficiency in this case is about percentage of light scattered in the direction needed. It makes about 70 percent of refraction and about 80 of reflection.

In the future such structures can be used for developing compact optical devices, as well as for designing an invisible raincoat.

It should be noted that scientists of various countries have been struggling to make this sci-fi device true for many years already. From time to time there is news about some achievements in this area; however it is still far from a full-fledged invisible raincoat.

In particular, just three months ago scientists from the Berkeley University in the USA announced about their creation of an invisible raincoat, which is only 80 nanometers thick and can take the form of any object and hide it from sight of a man or a video camera. Unlike the Russian scientists, the Americans used gold instead of silver for plasmon resonators. So far the material has been successfully tested on microscopic objects.