Nanoscale Device Makes Light Travel Infinitely Fast - ScienceNOW

Nanoscale Device Makes Light Travel Infinitely Fast - ScienceNOW: They've developed a tiny device in which the index of refraction for visible light is zero—so that light waves of a particular wavelength move infinitely fast.

The device consists of a rectangular bar of insulating silicon dioxide 85 nanometers thick and 2000 nanometers long surrounded by conducing silver, which light generally doesn't penetrate. The result is a light-conveying chamber called a waveguide. Researchers fashioned different devices in which the width of the silicon dioxide ranged from 120 to 400 nanometers...

Right at the cutoff wavelength, things get interesting. Instead of producing a banded pattern, the whole waveguide lights up. That means that instead of acting as waves with equally spaced peaks, or "phase fronts," the wave behaves as if its peaks are moving infinitely fast and are everywhere at once. So the light oscillates in synchrony along the length of the waveguide.