back to article It's curtains for you, copper: IBM boffins push the LIGHT FANTASTIC

IBM last month claimed a breakthrough in photonics – the practice of using light pulses rather than electrons to quickly send signals in chips. Big Blue claimed its boffins had successfully designed and tested a fully integrated wavelength multiplexed silicon photonics chip which would be capable of turning out 100Gbps optical …

  1. Dabooka

    Good article, and rather exciting potential, but

    'Do the math'?

    'Do the maths'


    1. This post has been deleted by its author

      1. Dabooka

        Re: Good article, and rather exciting potential, but

        No shit Sherlock, but this is a UK site (albeit with a few outposts in the colonies)

  2. Clive Galway

    That's fine, but...

    Will it run Crysis?

  3. Dave 32

    Silicon versus GaAs

    Interesting, but why are they concentrating on Silicon, rather than moving to Gallium Arsenide (GaAs)? GaAs is faster than Silicon. Plus, GaAs is a direct band-gap material, which means that it can produce photons directly from electron transitions, which Silicon mostly doesn't.


    1. Paul Crawford Silver badge

      Re: Silicon versus GaAs

      I think the main reason is there is SO MUCH silicon technology, experience, and fab facilities it is easy to make complex chips from it, whereas GaAs has been generally kept for the fastest of products where you don't have the same density of components but need higher speed. GaAs is more radiation-hard than silicon, but also less tolerant to heat. I'm sure others with more knowledge can provide a better informed answer though.

    2. John Smith 19 Gold badge

      Re: Silicon versus GaAs

      "GaAs is faster than Silicon. "

      Not it's not. Electrons move faster in GaAs. Holes (+ve charge carriers critical for CMOS) move slower.

      SiC is better and IIRC so is SiGe.

      But the core issue is that effectively you're needing two chips in the same package.

      The real break through with Silicon Photonics is a)Making Si emit light in the first place. b) Incorporating those structures into chip mfg process straightforward enough to use in a conventional production line.

      1. Nick Ryan Silver badge

        Re: Silicon versus GaAs

        Being a bit behind the head hurty field of nanoscale circuitry... isn't one of the advantages of GaAs that the circuits can be made smaller and use less power than the equivalent silicon based circuitry.

        On the other hand, the production techniques for GaAs really aren't anywhere near the level of refinenent of silicon. Possibly because it's more expensive to start off with and doesn't get any cheaper at any point.

  4. Anonymous Coward

    IBM is a strange company

    One one hand, they employ people so clever they're moving the world rapidly towards a completely new and exciting platform for computing, that will change everything. On the other hand, WebSphere.

    1. chris 17 Silver badge

      Re: IBM is a strange company

      @IBM is a strange company

      seems their management want to move more and more into consultancy where there is huge profit and less expense like in research and development. Hopefully we will hear more of their R&D efforts coming to the foreground & maybe the other giants will pay attention and start balancing their income by R&D too.

    2. asdf

      Re: IBM is a strange company

      >One one hand, they employ people so clever they're moving the world

      and on the other management uses stock buybacks to cash out their stock options leaving the R&D pipeline looking less optimistic in the future.

    3. Anonymous Coward
      Anonymous Coward

      Re: IBM is a strange company

      Ah WebSphere! A wonderful bunch of products. Some good some excellent some totalt shite.

      Kept me in gainful employ for the last 15 years (Not WAS I might add).

      Most of it works pretty well. MQ is a proper message queueing system that is far better than that toy called MSMQ. Well I'm biased because that it what I do for a living.

      I do agree that sometimes they (IBM that it) clearly suck with their product decisions and directions.

      1. Martin Budden

        Re: IBM is a strange company

        You utter bastards. I've been trying really hard to forget WAS and now you've made me think of it again.

  5. John Miles 1

    The real issue is how cheap you can make it

    There's nothing new about 4 x 25G WDM 100G interfaces, we already have 100G LR4 interfaces which will do exactly what they describe in the article, but they are very expensive and consume power & space. Presumably IBM have managed to produce a much smaller and lower power interface which will help a lot. I suspect it's still on a separate chip. If one could get true 'on-chip' optical 100G WDM interconnects that really would be something.

    1. Nick Ryan Silver badge

      Re: The real issue is how cheap you can make it

      The difference may be trivial but I thought that the wavelength had an effect on the data transferable on fibre therefore four different wavelengths down one fibre would support slightly different throughputs?

  6. Anonymous Coward
    Anonymous Coward


    "To illustrate the sea change it believes might be coming, IBM reckons new transceivers will be capable of sharing 63 million tweets or six million images in one second, or downloading a high-definition film in just two seconds."

    Since when is a tweet a unit of measurement?

    1. diodesign (Written by Reg staff) Silver badge

      Re: Tweets??

      Since now.


      1. Anonymous Coward
        Anonymous Coward

        Re: Tweets??

        So 140 bytes * 10.5 to get the filesize of images gives you 1.4K per image. You ain't going to get much image in there: Icons maybe; but nothing as large as -for example- an El Reg article image*.

        *Totally taking the piss there***

        ***Why hasn't W3C come up with a sarcasm font yet? They've finished's not like they're busy or anything.

    2. Paul Crawford Silver badge

      Re: Tweets??

      I think the official El Reg unit should be in kilowrists, the measure of simultaneous pr0n film streaming performance.

  7. Anonymous Coward
    Anonymous Coward

    Better work with standard CMOS

    Since Ginni paid Global Foundries to take the semi division... lock, stock, and obsolete equipment.

  8. Anonymous Coward
    Anonymous Coward

    Could you jam optical computers ..

    .. with a torch?

    If so, I suspect you may want to plan on having a lot of black paint around if optical computing takes off.

    1. Nick Ryan Silver badge

      Re: Could you jam optical computers ..

      ...and if you find yourself with too much black paint you could always paint a ship black. And then the insides black. And then all the controls and screens black. What could possibly go wrong? (Intergalactic rock stars aside of course)

      1. Apriori

        Re: Could you jam optical computers ..

        it's like, how much more black could this be? and the answer is none. None more black.

    2. Flocke Kroes Silver badge

      Depends on the packaging

      For at least a decade, the smallest chip packages have become so thin that they let light in. Somehow, this still surprises people. If the packing is not the smallest possible (or completely absent), then it can block all light except from the largest sharks.

  9. Martin Budden


    I assume the article picture must be of the technologically-challenged Australian prime minister, because I can see a kitten. Yes I do use the Stop Tony Meow browser extension. I love that extension.

    1. Thecowking

      Re: kitten

      I use ukitten in the UK for similar reasons, never do I need to see Nigel Farage's face.

  10. Anonymous Coward
    Anonymous Coward

    Kind of a minor breakthrough

    We've already got 25 Gbps transceivers, and have 100 Gbps networking based on four of them working together. Sure, it is notable they've shrunk it down so all four wavelengths can come from a single transceiver, rather than four transceivers, but it is still four 25 Gbps signals underneath the hood.

  11. Jim84

    Laser Phosphor TVS

    Surely if you can now get silicon chips that produce light this could be the ideal backpane for a laser phoshpor TV? Rear projection versions of this have been developed where a laser is scanned across the back of a screen using a chip of micro mirrors, but these screens are bulky. Having a tiny silicon laser for each sub pixel could solve that.

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