Ultrathin 'Invisibility Cloak' Can Match Any Background

Now, researchers have built an ultrathin "invisibility cloak" that gets around this problem, by turning objects into perfect, flat mirrors. Led by Xiang Zhang, director of materials science at Lawrence Berkeley National Laboratory, the group constructed a thin film consisting of a 50-nanometer-thick layer of magnesium fluoride topped by a varying pattern of tiny, brick-shaped gold antennas, each 30 nanometers thick. Shining a light, with a wavelength of 730 nanometers, or near-infrared, they fou