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Move over CD. . . . Scientists discover way to store image on photon
John Howell


John Howell, associate professor of physics, and his team have discovered a new technique for storing a digital image on a photon. It’s a potential breakthrough because not only were they able to store the image but also retrieve it entirely intact. The new technique could lead to more effective ways to store large amounts of data on light.
A “U” and an “R.” A digital image of those two letters is the first to be encoded on a photon and retrieved, fully intact. The optics breakthrough was made by a research team led by John Howell, associate professor of physics.
U and R image on a photon

First image stored and retrieved from a single photon.

While the initial test image consists of only a few hundred pixels, a tremendous amount of information can be stored with the new technique that may open the door to 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 Howell. “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 on the article published this month in the journal Physical Review Letters. “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.”
Howell’s group used a completely new approach that preserves all the properties of the pulse. The buffered pulse is essentially a perfect original; there is almost no distortion, no additional diffraction, and the phase and amplitude of the original signal are all preserved.
“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.
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