Researchers at the 4th Physics Institute of the University of Stuttgart and the Istituto Italiano di Tecnologia (IIT) in Milan have demonstrated a new mechanism for directing light in a naturally hyperbolic van der Waals material without conventional nanofabricated waveguides. The discovery opens new possibilities for integrated photonics, on-chip optical communication and future quantum technologies. The paper is published in the journal Nature Nanotechnology.
When a stone is dropped into water, circular waves spread outward from the point of impact. Light behaves similarly: When emitted from a localized source, it naturally propagates as spherical or circular wavefronts within a material. While this isotropic propagation is a fundamental property of waves, it is often undesirable in photonic applications where light must be guided efficiently along predefined paths.
Conventional optical technologies overcome this challenge using waveguides. In optical fiber communications, for example, glass fibers confine laser light and transport it over long distances with minimal loss. Similarly, photonic integrated circuits rely on nanoscale waveguides fabricated through complex lithographic processes, including resist coating, lithography and etching. These fabrication steps are technologically demanding and contribute significantly to manufacturing costs.
