The Information Age rides on beams of carefully controlled light. Because lasers form the arteries of modern communications networks, dexterous manipulation of light underpins the two definitive technologies of our times: telecommunications and the Internet.

Now researchers at Harvard University have developed a new way of steering and manipulating light beams.

Using droplets of liquid crystals--the same substance in laptop displays--the scientists can make a pane of glass that quickly switches from transparent to diffracting and back again. When the pane is transparent a laser beam passes straight through, but when the pane is diffracting, it splits the beam, bending it in several new directions.

The change is triggered by applying an electric field, so the pane could easily be controlled by the electric signals of a computer, offering a powerful new way to steer beams of light.

"Telecommunications could be one application, but at this point we're still looking at the basic properties of these droplets. Their potential is great, and it's hard to imagine all the ways engineers might use them," says David Weitz, Gordon McKay Professor of Applied Physics at Harvard University and lead scientist for the NASA-supported research.

Beyond telecommunications, one could imagine this light-steering ability being useful in astronomy. For example, these liquid-crystal panes could be used in reverse to combine (rather than split) beams of light from multiple telescopes. Combining light from many telescopes, a technique called interferometery, is a good way to search for distant planets around other stars.

Another application: a liquid crystal pane held in front of the mirror of a telescope could be used to "unwrinkle" light that has passed through Earth's turbulent atmosphere. Such adaptive optics telescopes could gain a crystal-clear view of the heavens from Earth's surface.

Above: Light from two or more telescopes can be combined to reduce the glare of distant stars, revealing faint planets. Could this be an application for liquid crystal technology?

The many uses of steering light are part of the reason that NASA recently decided to award Weitz and colleagues a grant for this research. In addition, NASA can provide a unique environment for experimenting with liquid crystals: low gravity.

"We've already seen several exciting results from fluid physics experiments done in Earth orbit," says Brad Carpenter, lead scientist for NASA's Physical Sciences Research Division. "This latest project of Dr. Weitz, who has already completed some successful experiments on the International Space Station (ISS), was selected for funding with the vision of aiding advances in optical information technologies".