Researchers at the
While the initial test image consists of only a few hundred pixels, a tremendous amount of information can be stored with the new technique.
The image, a ‘
‘It sort of sounds impossible, but instead of storing just ones and zeros, we’re storing an entire image,’ said John Howell, assistant professor of physics and leader of the team that created the device, which is revealed in the online issue of the journal Physical Review Letters. ‘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,’ said Ryan Camacho, Howell’s graduate student and lead author on 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.’
Optical buffering is currently a salient topic because engineers are trying to speed up computer processing and network speeds using light, but their systems slow down when they have to convert light signals to electronic signals to store information, even for a short while.
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. Howell is even working to demonstrate that quantum entanglement remains unscathed.
To produce the
The light can be thought of as a particle and a wave. As a wave, it passed through all parts of the stencil at once, carrying the ‘shadow’ of the
‘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,’ said Alan Willner, professor of electrical engineering at the
Howell has so far been able to delay light pulses 100 nanoseconds and compress them to one percent of their original length. He is now working toward delaying dozens of pulses for as long as several milliseconds, and as many as 10,000 pulses for up to a nanosecond.
‘Now I want to see if we can delay something almost permanently, even at the single photon level,’ said Howell. ‘If we can do that, we’re looking at storing incredible amounts of information in just a few photons.’