First topological insulator made for photons

Science News : Topological insulators, first proposed in 2005, allow electrons flowing along their surfaces to pass obstacles with no difficulty. Now Mordechai Segev of the TechnionâIsrael Institute of Technology in Haifa and his colleagues have extended the realm of topological insulators to include photons. They etched hundreds of helical waveguides into a block of glass to serve as wires for light. Because the waveguides were packed into a tight honeycomb structure, the light in one waveguide would interfere with the light in another and they would cancel each other out, except along the outer edge of the waveguides. That resulted in photons being steered to the waveguides’ edges and confined to the surface of the glass. When they reached an edge of the glass block, the photons made the turn and continued on their way, and none were scattered by surface imperfections. Segev’s team believes the discovery can be adapted for optical transmission technology to increase data transfer capabilities.