At first sight, these new materials are simply odd: thin as a hair, transparent and full of holes. Like the optical fibers that are the mainstay of the telecommunications industry, they're made of glass. But there the similarities with conventional materials come screeching to a halt.

The center of each of these novel fibers-which are made at the University of Bath, in England-is hollow. In existing optical fibers, light is transmitted through a glass core. In the fibers made at Bath, light travels unhindered through air. The light beam is confined to the hollow core by the holes in the surrounding glass material, which looks like a honeycomb in cross section and creates a strictly no-go region for light. The ability to confine light in air this way, says Philip Russell, a Bath physicist, "could completely revolutionize telecommunications."