Slow Light = Fast Computing

yohaas writes "The Washington Post is reporting that scientists have been able to slow the speed of light while still maintaining its ability to transmit information. The researchers have even developed a way to 'tune' the process, modulating how fast or slow the light goes within controlled circumstances. From the article: 'Scientists said yesterday that they had achieved a long-sought goal of slowing waves of light to a relatively leisurely pace and using those harnessed pulses to store an image. Physicists said the new approach to taming light could hasten the arrival of a futuristic era in which computers and other devices will process information on optical beams instead of with electricity, which for all its spark is still cumbersome compared with light.'"

Comments

Re:*cough*bullsheet*cough*

[ThanatosMinor]

Perhaps they meant only one photon at a time. The interference pattern that light creates on a screen does not depend on whether you send one photon through at a time or an entire beam.

Re:*cough*bullsheet*cough*

[julesh]

There's no way a single photon makes a stencil image.

There's a well-known effect that when you perform Young's double-slit experiment with single photons, the interference patterns still remain. If a single photon can interfere with itself, I'm sure it can make an image.

A much better scientific description here

[viking80]

Here is a half decade old article that describes the process well. It also uses units such as nm and Kelvin instead of thigs like "seven times around the earth" and "about 450 degrees below zero"

http://www.physics.hku.hk/~tboyce/sf/topics/lightf reeze/lightfreeze.html

Re:Moo

[exp(pi*sqrt(163))]

The latter article is about phase velocity. Phase velocity is the speed at which the individual peaks and valleys of the signal appear to travel. But peaks and valleys aren't actual 'things' and you can't transmit information using them. (See here.) This latest story is about the rate at which you can transmit information, so it's about group velocity.

Despite the fact that the theory was worked out more well over a century ago, almost every modern pop science story about manipulating the speed of light leaves out these crucial points.

Re:*cough*bullsheet*cough*

[mhall119]

Yes, but when they contact something, the act like a particle. Even in a dual slit experiment, a single photon will produce only a single contact, not a pattern. The pattern arises from the non-uniform distribution of multiple single photon contacts. The original comment's confusion was thinking that the hologram was produced by a single photon, rather than a succession of individual photons.