Researchers of AMOLF and TU Delft have seen light propagate in a special material without it suffering from reflections. The material, a photonic crystal, consists of two parts that each have a slightly different pattern of perforations. Light can propagate along the boundary between these two parts in a special way: it is ‘topologically protected’ and, therefore, does not bounce back at imperfections. Even when the boundary forms a sharp corner, the light follows it without problem. “For the first time, we have seen these fascinating light waves move at the technologically relevant scale of nanophotonics,” says Ewold Verhagen, group leader at AMOLF. The results are published on March 6th in the scientific journal Science Advances. Read more