Large-scale optical cloaking in multiple directions

MIT Technology Review : Last week researchers revealed an optical invisibility cloak large enough to hide a human, but it was limited to only working in a single direction. That achievement has already been surpassed by Hongsheng Chen of Zhejiang University in China and his colleagues. They realized that with most invisibility cloaks, researchers worried about maintaining light’s phase and polarity, but that it isn’t necessary for visible light because humans aren’t sensitive to changes in those characteristics. That realization allowed Chen and colleagues to use conventional optical components to steer light around a hidden central area. They demonstrated two versions of their cloaking device: The first is square, which hides the central area from four directions; the second is a hexagon, which works in six directions.