Optical Computer Made From Frozen Light

neutron_p writes "Scientists at Harvard University have shown how ultra-cold atoms can be used to freeze and control light to form the "core" - or central processing unit - of an optical computer. Optical computers would transport information ten times faster than traditional electronic devices, smashing the intrinsic speed limit of silicon technology. This new research could be a major breakthrough in the quest to create super-fast computers that use light instead of electrons to process information. Professor Lene Hau is one of the world's foremost authorities on "slow light". Her research group became famous for slowing down light, which normally travels at 186,000 miles per second, to less than the speed of a bicycle."

Comments

Can a physics geek explain how you "freeze" light?

[stratjakt]

Obviously it's not simply a temperature thing, since most of space is absolute zero, and I can see stars and suns and stuff. So it's not freezing light as in freezing water.

So how exactly do you stop photons from moving? How does this affect relativity (e=mc^2)? How does this affect our perception of the universe - ie; if the light from the star that we think is 10,000 light years away is only moving 20mph or so, it could really be millions of light years away?

Does like, time slow down? My heads spinning. Freeze sounds like the wrong word.

Photon size problem

[Laaserboy]

1) Wavelengths are too big: 1 micron is now a large number, and optics doesn't work much smaller than this.

This poster is correct. Since I have a Ph.D. in the field and the parent obviously knows something about optics, I might as well respond to the parent's critics.

IR photons are BIG. Forcing light to bend around corners is difficult. A waveguide must have a very high index of refraction if it is to be used to bend light within a reasonable radius. To the extent a Bose-Einstein Condensate helps this problem is encouraging if you don't mind cooling your computer to 2 millikelvin.

The speed of these optical computers always seems to come down to limitations of the silicon processors that work in conjunction with the light.

It's just a Bose-Einstein Condensate. These projects take time. While we are enamored with this BEC project, some poor grad student is working on carbon doping. Higher doping might improve the world of electronics far more than another optical computer claim.

I visited Hau's website and did, though, enjoy her papers. I just don't think the press release accurately portrays the low engineering potential of this work.