Scientists have created a new kind of hologram that could improve efforts to prevent counterfeiting of cash and credit cards.So-called "metaholograms" have been created by scientists who developed a "metasurface" consisting of transparent glass surfaces covered with arrays of nano-fins. These are microscopic bars of silicon each 85 nanometers wide, 350 nanometers long and 1,000 nanometers high, located about 500 nanometers from each other.In the study, Broadband and chiral binary dielectric meta-holograms, the team reveals how these new holograms could be seen a much closer distances, at varying angles, and in a wide range of wavelengths, from visible to near-infrared, reported Inside Science.The new metaholograms can project different images depending on the direction in which light waves vibrate, a property known as polarization. This could make them useful in preventing counterfeiting, such as with cash or credit cards, said study lead author Mohammadreza Khorasaninejad, a physicist at Harvard
Research reveals hologram breakthrough
