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'Slow' Light To Speed Up the Net
JPawlak writes "Researchers believe that it may be possible to increase the speed of the Internet by slowing down certain parts of it by using metamaterials. Metamaterials could be used to replace the bulky and slow electronics that route Internet information, allowing for faster Internet speeds. As data nears its destination, the frequencies must be separated. The light must then be converted into electrical signals, which are stored, routed, and converted back into optical signals. The conversion not only adds significant cost and complexity to the process, but slows down the transmission as well. However, if the light signals could be slowed during the switching process, they would not need to be converted into an electrical signal. 'The ability to slow the light could be a tremendous force for telecoms that is sure to enhance speed and efficiency,' says University of California professor Xiang Zhang."
Am I the only one who thinks that sounds a bit paradoxical?
"The metamaterials work of Professor Xiang Zhang and his team at the University of California at Berkeley is being highlighted in a paper Wednesday in the online version of the journal Nature and in another appearing Friday in the journal Science."
http://www.newsfactor.com/story.xhtml?story_id=61321
I thought one had to use repeaters every once and a while (every few km?) anyway in fiber optics, which AFIAK work by doing just what this is talking about avoiding, translate light into electrical signals back into light. Why is it so bad to have this conversion happen at the switch if it's already having to happen periodically anyway, and won't using this technique probably just result in more repeaters in the network? Or is it just that the process of multiplexing and de-multiplexing (if I have the term correct) is particularly slow? Can anyone with more detailed knowledge of these systems comment?
"You call it a new way of thinking; I call it regression to ignorance!" -- Operation Ivy
http://www.nature.com/nature/journal/vaop/ncurrent/full/nature07247.html
C'mon, if we ever want to overcome the limits of general relativity and make interstellar travel commonplace, we should be trying to invent ways to make light go faster, not slower!
You know, like on Futurama... right?
It should be referred to as velocity challenged.
Browsing at +1 - no ACs, I ignore their posts. So refreshing!
Or we could remove the unconstitutional packet sniffing equipment on the backbone.
Modding me -1 troll doesn't make me wrong.
Demultiplexing multiple channels from an optical fibre isn't routing. This technology could speed the mux/demux stuff up tremendously (saving a lot of cable) but you'll still have a bottleneck at the actual routers that need to read and direct individual packets.
One of these days I'm moving to Theory - everything works there
This article is claiming that metamaterials can give slow light. An optical switch needs a slow light component - where electronic switches can delay packets by temporarily storing them in memory, in an optical switch it would be easier to delay packets by slowing them down rather than stopping them outright. You'd want to delay a packet if it was about to collide with another packet. The actual routing would be done by optical logic, which is very hard and not being claimed by this research group.
Slow light can be achieved in other ways, too - e.g. photonic crystals.
What this is all about is finding some way to do short-term optical packet storage in switches. As yet, there's no optical equivalent of RAM. All-optical gates can be built, and simple logic is possible, but there are no good storage elements. So at present there are optical switches (no queueing), but not optical routers. In order to combine packets from multiple input paths to a single output path, some of the packets need to be delayed until there's free time on the output path. Routers have output queues in RAM to do this. The idea here is to find some way to do this without RAM.
Optical delay lines are simple enough; they're just sections of fibre optic. There are designs for pure optical routers which have little delay loops to which packets can be diverted while waiting for free time on an outgoing line. The delay is fixed, so this sort of thing tends to work better if all the packets are the same size, as in ATM. This new material, where propagation speed varies with light frequency, might be useful as a variable-delay storage medium. Maybe.
This is an area of much active work. Several clever ways have been developed to work around the no-RAM problem. Sort of. None of them are really satisfactory, in the sense of being able to build an optical router that does what an electronic router does now. The network backbone has to be designed around the limitations of the optical technology.
(Note that some optical switches are referred to by their vendors as "routers". They're not. Some of them, the ones with MEMS mirrors, for example, are circuit switches, like a classical phone switch.)
I had a vision of a Japanese commuter waiting for a Bullet train, but the train destination was written on the front of the train and the train didn't stop. Not much of an analogy, but a funny image nevertheless.
Isn't the speed of light supposed to be constant?
No. Speed of light in vacuum is constant.
Ever heard of ÄOEerenkov radiation which is produced when some particles travel faster than light in water? Off topic, but I always find it beautiful to watch.
hilarious
Delaying or buffering the analog light signal is just a teensy part of the process. A typical packet needs to be detected, isolated, have its CRC checked, be inspected, have its addresses twiddled, have the CRC recalculated, and then queued for forwarding. It's gonna be really hard to do these things optically.
In addition most optical delay devices are going to have a strong phase shift over frequency characteristic, a very bad thing.
Methinks the materials folks should stick with what they know and not speculate on the uses.
Technically, no. The speed of light in vaccumn, however, is constant.
What?
Now the telco companies will have another way to missell their "faster-than-the-speed-of-light" broadband!
This is using cut-through, not checking the CRC etc. It's just using a vessel with a known return time to "store" the packet while the route is chosen.
I guess technically it's a hybrid of S&F and C-T.
I recommend Microsoft products.
Researchers believe that it may be possible to increase the speed of the Internet by slowing down certain parts of it
Didn't Comcast already try that?
Taxation is legalized theft, no more, no less.