The discovery could advance integrated photonics, on-chip optical signal transmission, and future quantum technologies.

A nanoscale gold antenna placed on a crystal can send infrared light along one narrow route, even though no physical waveguide has been carved into the material.

Researchers at the 4th Physics Institute of the University of Stuttgart and the Istituto Italiano di Tecnologia (IIT) in Milan demonstrated this mechanism in a naturally hyperbolic van der Waals material. The result could support integrated photonics, optical communication on chips, and future quantum technologies.