Controlling the flow of light

Researchers at Columbia Engineering School have built optical nanostructures that enable them to engineer the index of refraction and fully control light dispersion. They say it is possible for light (electromagnetic waves) to propagate from point A to point B without accumulating any phase (resulting in no delay), spreading through the artificial medium as if the medium is completely missing in space. The study was led by Chee Wei Wong, associate professor of mechanical engineering, Columbia Engineering.

“The phase control of photons is really important,” said Wong. He said this was a big step forward in figuring how to carry information on photonic chips without losing control of the phase of light. Researchers can now control the flow of light—the fastest thing known to us. This can enable self-focusing light beams, highly directive antennas and an approach to cloak or hide objects, at least small ones, or a narrow band of frequencies.