A new type of infrared polaritons at the surface of bulk crystals

An international team has reported in Nature the first observation of ghost polaritons, which are a new form of surface waves carrying nanoscale light strongly coupled with material oscillations and featuring highly collimated propagation properties. The research team observed these phenomena over a common material—calcite—and showed how ghost polaritons can facilitate a superior control of infrared nano-light for sensing, signal processing, energy harvesting and other technologies.