'Corkscrew' Light Could Turbocharge Internet 82
ananyo writes "Twisty beams of light could boost the traffic-carrying capacity of the Internet, effectively adding new levels to the information superhighway, suggests new research. In the last few years, different groups of researchers have tried to encode information in the shape of light beams to ease congestion, using a property of light called orbital angular momentum. Currently, a straight beam of light is used to transmit Internet signals, but certain filters can twist it so that it corkscrews around with varying degrees of curliness as it travels. Previous experiments using this effect have found that differently shaped light beams tend to jumble together after less than a meter. Now, a team of researchers from Boston University in Massachusetts and the University of Southern California in Los Angeles has found a way to keep the different light beam shapes separated for a record 1.1 kilometers. The most imminent use of the cables, the authors say, might be to install them to span the short distances between servers on giant 'server farms', used by large Web companies such as Facebook."
I swear (Score:2)
I saw a piece on this back in the early 90s on Daily Planet - I could never find it again and no one else seemed to remember it. Glad to know I'm not crazy!
Re:I swear (Score:5, Funny)
The one has nothing to do with the other ... you may correctly remember, but you might still be crazy. ;-)
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I'm not crazy. You're the one who's crazy!
All I wanted was a Pepsi...
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Well done!
Wait, what are you talking about, WE decided!?
MY best interests?! How do you know what MY best interest is?
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Your memory is failing you. You read it back before you were transported back in time.
Re:Awesome! (Score:5, Funny)
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Interesting idea, horrible post (Score:1)
It's definitely a cool idea, but sheesh, this is Slashdot, people! We don't need a kindergartner's description of how the Internet and fiber optics work.
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90ies called, want buzzwords back! (Score:2)
It's 2013, does that make the term "Information Superhighway" retro?
Re:90ies called, want buzzwords back! (Score:4, Funny)
It's 2013, does that make the term "Information Superhighway" retro?
Judging from the summary, their idea sounds more like the Information Spaghetti Junction.
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Hmmm, if the internet is a series of tubes, then this is an intertwined set of bendy straws.
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The internet is more like an ocean than a highway, anyway. Complete with surfers and pirates.
-- hendrik
Will this need new cables and other hardware (Score:2)
If this needs new cables then maybe in the data center but installing them all over place will cost a lot + all the hardware that will need to be updated.
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Basically this has been done before, but it isn't very effective because it only retains its information carrying capacity for very short distances. What these guys have done is made the information coherent for over a kilometer. It could theoretically go for longer, but their cable was only made about a kilometer long. While interesting, it would require replacing cables rather than being useful for existing cables.
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Kind of like complaining, "But I'll have to get new shoe laces!" when you are buying shoes.
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Generally, the equipment on the end is the shoelace and the cable is the shoe. How much do you think it costs to lay a mile of fibre?
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Generally, the equipment on the end is the shoelace and the cable is the shoe. How much do you think it costs to lay a mile of fibre?
From the RTFA dept...
The most imminent use of the cables, the authors say, might be to install them to span the short distances between servers on giant 'server farms', used by large Web companies such as Facebook.
Not germane to the subject seeing that I haven't seen a server farm that is more then a mile across...
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Which is precisely why it is being targeted at server farms: the cost of pulling up already-lain fibre in outdoor settings just isn't worth it, even with this additional capacity available.
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Not any longer. I work at a telco and a while back we got smarter. Rather than bury strait fiber, and have to dig it up when technology changes, we now bury flexible PVC tubing that the fiber rides in. When we need to change it, rather than dig it up at great expense, we find the particular fiber we want to replace, and just pull it out of the housing by hand. Then we use a device that shoots the new fiber through to the other side with compressed air. It's really neat to watch several miles of cable just p
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The most imminent use of the cables, the authors say, might be to install them to span the short distances between servers on giant 'server farms', used by large Web companies such as Facebook."
Re:worst description of polarization ever (Score:5, Informative)
It's the "worst description of polarization ever" because it's apparently not polarization [wikipedia.org]:
The orbital angular momentum of light (OAM) is the component of angular momentum of a light beam that is dependent on the field spatial distribution, and not on the polarization.
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It does sound like right or left hand circular polarisation to me too.
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I think of it as being analogous to injecting separate beams of light at different angles, having them bounce back-and-forth between the walls at different distances between bounces, and emerge at angles corresponding to the angles at which they entered.
Of course it's not angle of flight that's in question, but another property of the light propagation that can be varied to allow different beams to propagate down the fiber and be separable at the far end. But they're still separate because each beam's cros
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What it means is that they're using other than the TEM mode of multimode fiber. It can be done but it has problems with dispersion and decoherence with distance. Every optical and probably ever electromagnetics engineer learned about this in school and most of us concluded that single-mode fiber was preferable because it doesn't have those issues.
The standard method for multiplexing signals on fiber is therefore to put it on different colors instead of into different excitation modes. That way they can b
It pains me to say this, but (Score:5, Informative)
People are probably beter off reading the wiki [wikipedia.org]...
Key bit of information...
OAM multiplexing can not be implemented in the existing long-haul optical fiber systems, since these systems are based on single-mode fibers, which inherently do not support OAM states of light. Instead, few-mode or multi-mode fibers need to be used. Additional problem for OAM multiplexing implementation is caused by the mode coupling that is present in the fiber, making direct-detection OAM multiplexing still not being realized in long-haul communications. In some specialty fibers, OAM states were transmitted with 97% purity after 20 meters.
Basically this demonstration technique uses specially designed fibers that can carry the "donut" TEM mode required for OAM which is the reason they made a comment that the most likely for fibers the implement this technique "might be to install them to span the short distances between servers on giant 'server farms'"...
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Is there actually any capacity crunch on the physical fiber itself that makes it worth replacing? My understanding is that existing DWDM hardware can pump multiple terabits per second through a single fiber strand, and that the reason pumping a terabit through fiber requires multiple transceivers is simply because the electronics can't drive data rates, not because of any limitation of the fiber...
It seems that OAM would have the same problem; you still need electronics that don't exist if you want to push
Re:It pains me to say this, but (Score:4, Interesting)
You've hit on the real reason nobody is interested in OAM/Spatial mutliplexing. Depending on the vendor, we can light 80 to 160 channels of DWDM today on a pair of fibers, and go for thousands of kilometers in a well planned system.
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This is what WDM (Wavelength Division Multiplexing) means. (DWDM = Dense Wavelength Division Multiplexing).
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What do you think DWDM is?
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Bandwidth is a ratio of data size to speed. (Data Size / Time) If data size increases by a lot, but the speed slows down a little, it is a net bandwidth is increased.
The example of having a truck loaded up with hard drives driving down the highway has a larger bandwidth than many other options.
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Yes, color is used. But not the way you think it is.
Chromatic dispersion causes different wavelengths (colors) to propagate at different speeds. So what would start out as a coincident red and blue bit wouldn't stay that way very long. But using separate colors as one would use separate fibers with each carrying its own data stream does work.
then the color would be purple.
Your eyes and brain work that way. Other sensors don't. A 'red bit' plus a 'blue bit' will not trigger a purple sensor.
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What you're describing would be WDM, and this is OAM or Spatial Multiplexing depending on who you talk to.
Your eyes and brain work that way. Other sensors don't. A 'red bit' plus a 'blue bit' will not trigger a purple sensor.
That's not really true, photodiodes and avalanche photodiodes are not channel specific. I can connect a transmit from a 1560.61 to a RX of a 1558.98 and they will work just fine. Most are wide-band and will happily receive anything from 1250 to 1650 nanometers.
If I mix those wavelengths with a combiner and send them into a receiver, I'll get a loss of frame because the signals conflict. The channels ha
Who'll patent it first? (Score:1)
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Since this was created at a University it is unclear on which company will attempt to patent it first. Any bets? Should be start a pool?
Why wouldn't the university patent this? That would be what normally happens.
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My bet is Apple will try. but it doesn't matter who patents it now because the university already holds prior art due to having published the scientific paper first. There is no rule that a university cannot hold a patent, the only shitty thing is if a student was the one that actually invented it, it's his professor that will take credit as the inventor. That's why you wait till you graduate before you invent shit.
How useful is this, really? (Score:2)
If they ever got the distance extended, I could see this being handy for long-haul links (although is it really better than a CWDM or DWDM?) But over intra-rack links, it'd have to have a pretty small premium over current technologies to be able to justify using it over just laying another strand of fiber.
In all but HPC applications bandwidth is rarely an issue anyway. You might occasionally use those for trunk lines, but again, why not just lay another strand?
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Laying another cable is crushingly expensive, but you're right this technique is still so vastly inferior to WDM that nobody is seriously pursuing it outside of science projects.
use in conjunction with WDM maybe? (Score:2)
It seems at least plausible that this could be used in conjunction with some form of WDM to get higher densities than either alone.
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they have similar marketing spew already for their overpriced fiber optics:
http://www.monstercable.com/productdisplay.asp?pin=3792 [monstercable.com]
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From the article:
The work published today used clockwise and anticlockwise versions of twisted light with a specific curliness, but Ramachandran says that the team has since done other research that suggests that about ten different beam shapes can be used to convey information.
That is exciting because each shape could potentially act as an entirely new level of traffic on the information superhighway. On each level, streams of data could be further divided into narrow lanes of colour, maximizing flow. "We showed a new degree of freedom in which we could transmit information," says Ramachandran.
It sounds like you are getting ten times the information. Even if latency doubled, it might be worth the tradeoff with applications such as file transfer and music/video streaming.
Can not be used on existing fiber (Score:2)
Do they realize how much fiber is lit at gigabit and below? 10ge is hitting mainstream and 40 and 100 following on quickly. CWDM is dirt cheap and DWDM is getting there as well. Replacing all the long haul fiber is a non starter could be useful in 100ge short reach dropping it from 10 or 4 lanes to 2.
One the physical side 25gbps looks to be the plateau we are hitting 16 lanes gets 400ge ports.
bad move reference... (Score:2)
I don't understand (Score:2, Informative)
How corkscrewing light will turbocharge anything...
Will the exhaust light impact an impeller that then compresses the light on the other side?
Because (I direct this to every idiot who mis-uses the term "turbocharge") THAT is what a TURBOCHARGER is.
A compressor that is powered by exhaust gas.
If whatever damn device you are speeding up does not contain: /end of rant
an waste exhaust-driven impeller
an impeller driven compressor
then it is NOT turbocharging.
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fine, we'll twincharge and supercharge and hybridcharge our CPU from now on
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Works Great (Score:1)
Works great as long as all your cables are perfectly straight. If you want to bend the cable, you need to plug it into an angled repeater.
The repeater, of course, requires an external power source.
how is this different from this story in 2012? (Score:1)
This sounds like what these guys were doing: http://hardware.slashdot.org/story/12/06/25/1215246/twisted-oam-beams-carry-25-terabits-per-second [slashdot.org]
Not sure if its the same groups or not, but pretty much the same idea.
solving a non-problem (Score:2)