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Researchers are small and thin ‘invisibility cloak’
It’s investigators managed to make a small object “disappeared” under an ultrathin metamaterial. Due to the reflecting surface of the material to be processed so that it consists of small, light-scattering antennas, it was an object to make from 36 to 36 micrometer “invisible.”
It would also have the material still does not have a feature that other metamaterials in the lichtombuigende category, namely the ability to hide objects with sharp edges. The authors of the article in Science also say that their material presumably is scalable. The “invisibility cloak” of researchers from the Lab Berkeyley able to remove the object characteristics of the reflected light from a certain angle. It allows an object does not disappear from the environment. This can be due to the way the small gold ante neat, or rather golden rectangles of various sizes, to compensate for the thin gold film 80 nanometer thick scattering of light. The used red light with a wavelength of 730 nanometers, is in the visible spectrum. The latter is special: many other experiments with metamaterials, which often have to bend light around objects, work with us invisible wavelengths.
Normally, an object would be visible under a thin film because the light hits the covering film and reflected back in different directions. Because the light bouncing in all directions, the object is visible. With this “coat” or below these gold foil with its antennas, the scattering is prevented. Therefore reflect the light waves in the same direction as the back surface where the object is located. Because the tiny gold ante neatly light in different ways can rebound, an object can not just ‘disappear’ or appear flat, but also completely change shape, as if the surface is wrinkled or puckered.
The antennas work by a phase change of the light waves. This is because each antenna is just too small or too large in order to completely reflect the incident light. By adjusting the size of the antennas, it is possible through the phase change to allow the light reflectance as if regular reflection occurs. The latter already shows an important limitation: the casing has to be exactly designed for a specific object that it must cover in which the jacket can make anything seem flat or some other form. Something does not disappear in the area. Despite this ‘cloak’ made relatively easy on a larger scale could be the object underneath or behind the film can never move. Also, when the jacket only with a limited number of wavelengths, and it is also not possible to cover sharp or very large objects as there is a shadow effect occurs. These shadows are not yet lift.Viewing:-96
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