Currently, optical buffering is a hot field, as engineers are looking for speeding up computer processing and networks using light.

But the systems get sucked when they must convert light signals to electronic ones to store information, even for a short period.

Now, a team at the University of Rochester has made a crucial optic finding that permits them to encode an entire image data into a photon, store it, and then retrieve the image intact.

A huge amount of information can be stored with the new technique as an image requires a few hundred pixels.

The image was achieved using a single pulse of light and a hundred of these pulses can be stored at once into a tiny, four-inch cell, fact that can open the era of optical buffering: storing information as light. "It sort of sounds impossible, but instead of storing just ones and zeros, we're storing an entire image," says John Howell, associate professor of physics and leader of the team that created the device.

"It's analogous to the difference between snapping a picture with a single pixel and doing it with a camera--this is like a 6-megapixel camera."

"You can have a tremendous amount of information in a pulse of light, but normally if you try to buffer it, you can lose much of that information," says Ryan Camacho, Howell's graduate student and lead author of the article.

"We're showing it's possible to pull out an enormous amount of information with an extremely high signal-to-noise ratio even with very low light levels."

The new approach perfectly preserves the properties of the pulse through buffering; there is almost no distortion, no additional diffraction, and the phase and amplitude of the original are kept.

To produce an UR image, the researchers simply shone a beam of light through a stencil for U and R. They decreased the light so much that only a single photon passed through the stencil. At that scale, light acts as both a particle and a wave; that's why - as a wave - it passed through all parts of the stencil at once, carrying the "shadow" of the UR with it.

The light pulse entered after that a four-inch cell of cesium gas at a temperature of 100 degrees Celsius, where it was slowed and compressed, permitting many pulses to be stored inside the small tube at the same time. "The parallel amount of information John has sent all at once in an image is enormous in comparison to what anyone else has done before," says Alan Willner, professor of electrical engineering at the University of Southern California and president of the IEEE Lasers and Optical Society.

"To do that and be able to maintain the integrity of the signal--it's a wonderful achievement."

Light pulses were slowed to 100 nanoseconds and compressed to 1 % of their original length.

The researchers are now looking to delay dozens of pulses to a few milliseconds, and as many as 10,000 pulses to a nanosecond. "Now I want to see if we can delay something almost permanently, even at the single photon level," says Howell. "If we can do that, we're looking at storing incredible amounts of information in just a few photons."

Image credit: University of Rochester