Storing Light In Chips

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Posted by timothy on Saturday February 21, 2004 @01:42AM from the not-grandma-utz's dept.

Roland Piquepaille writes "Recently, researchers have "stopped light" by storing light pulses in hot or extremely cold gases (check these former stories on Slashdot or at BBC News Online). Now, scientists from Stanford University have devised a method to store light pulses under ordinary conditions. In Light-storing chip charted, Technology Research News says this opens the way for all-optical communications switches, quantum computers and quantum communications devices. The researchers plan to demonstrate this technique by trapping microwave signals within a year. They think that a prototype which works at optical frequencies could be made in two to five years. This overview contains more details and references."

11 of 164 comments (clear)

Schrodinger by andy666 · 2004-02-21 01:44 · Score: 5, Interesting

This was predicted by Schrodinger in the 30's - it really took them a long time to do it.
1. Re:Schrodinger by Anonymous Coward · 2004-02-21 02:10 · Score: 5, Funny
  
  And to this date, nobody actually *tried* tying buttered toast to a cat's back, for the hovering-cat effect!
2. Re:Schrodinger by Winkhorst · 2004-02-21 02:12 · Score: 5, Insightful
  
  Hey, it took centuries to get around to using Copernicus's orbital equations with spacecraft. This is the beauty of basic research. It eventually has a practical use, but you can't base its validity on how long it takes to use it. And you have to distinguish between research and the ability to invent something. As John W. Campbell once pointed out, the Classical Greeks had everything necessarily to invent the phonograph, though it wasn't until Edison that somebody got around to doing it. In that particular case, it was the mental rut into which the Greeks had worn themselves that kept them from making much practical progress, thus leading to the return to power of irrational religion and the eventual rise of the Dark Ages.
  
  --
  "Is this Winkhorst a nova criminal?" "No just a technical sergeant wanted for interrogation."
3. Re:Schrodinger by andy666 · 2004-02-21 02:36 · Score: 5, Informative
  
  It isn't Copernicus' equations that are used for spacecraft, but Newton's F=ma, Newton's law of gravitation, and an occasional use of General Relativistic corrections.
Not hard by Squareball · 2004-02-21 01:46 · Score: 5, Funny

Storing microwaves within a year isn't very hard. I mean a year is huge!
Re:Practicality in Displays by cubic6 · 2004-02-21 01:48 · Score: 5, Insightful

Well, if the light is held, it's not getting to your eyes, and thus not making a visible picture. So in that particular instance, I would think that this wouldn't help very much.

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Karma: Contrapositive
Please tell me how this time it's different. by Mysteray · 2004-02-21 01:55 · Score: 5, Interesting

Keep in mind that this is only theoretical. The researchers plan to demonstrate this technique by trapping microwave signals within a year. They think that a prototype which works at optical frequencies could be made in two to five years.

Does this sound like another one of those "breakthroughs" in optical/quantum computation where prototypes are "just around the corner" and commercialization is "just a few years away", yet it never happens?

Tell me how this time it's different. Does it work on standard fab processes?

I would really love a CPU with a terahertz clock. I guess it would still be I/O bound, though.
Re:Please tell me how this time it's different by robbot · 2004-02-21 02:11 · Score: 5, Insightful

Yeah I was excited reading the article until this quote.

"The work would have been more impressive had the authors demonstrated the stopping of light experimentally, he added." Raymond Chiao, a professor of physics at the University of California at Berkeley.

Yup one of those 2-5 years things again, like so much else...
Re:Practicality in Displays by mean+pun · 2004-02-21 02:21 · Score: 5, Informative

LCD's do that already! They stay in their state until they get a signal to change their brightness. They arent scanned like CRTS are! Thats why they look more clear/are thinner etc/.
That's wrong on a lot of levels: LCDs do not store light, they selectively block it. Liquid Crystals (that give LCDs their name) do not stay in a fixed state on their own, but must be regularly aligned. Small and old displays use scanning very similar to CRTs, modern and large displays have a memory cell for each pixel.
Re:Is it really storing light? by Angstroman · 2004-02-21 03:00 · Score: 5, Informative

Yes, the concept (it is only a theoretical concept, not a chip, in the paper) does store the light. When the optical pulse is completely within the postulated structure (meaning only a very short pulse can be stored), a modulation of the refractive index causes the fields associated with the pulse to be stored in the internal cavities of the crystal. Reversing the refractive index change causes the stored fields to reform a traveling wave, which exits the structure. The way that you know that the pulse has been stored in the computer simulations is that after the first refractive index change, nothing comes out of the structure. After the second change, a pulse emerges that has the same shape as the one that was sent in.
Re:Speed of light? by Weird+O'Puns · 2004-02-21 03:46 · Score: 5, Informative

If you had just looked at some links in your Google search you would have found this:

To be precise, what we usually call the "speed of light" is really the speed of light in a vacuum (the absence of matter). In reality, the speed of light depends on the material that light moves through. Thus, for example, light moves slower in glass than in air, and in both cases the speed is less than in a vacuum. Link