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News Researchers develop all-optical 'transistor'

Discussion in 'Article Discussion' started by Gareth Halfacree, 5 Jul 2013.

  1. Pinguu

    Pinguu Noot Noot!

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    Huh? I thought as fundamental particles, photons don't have dimensions.
     
  2. Cobalt

    Cobalt New Member

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    Photons have a wavelength which is what is being referenced here. All this talk of light beyond UV is nonsense though. How are you going to make the x/gamma rays? Free electron lasers were pretty big last time I checked. Unless you don't need a coherent source for the photons.
     
  3. Corky42

    Corky42 Where's walle?

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    Small X-ray emitters are already being developed.
    http://en.wikipedia.org/wiki/X-ray_generator#Advances_in_X-ray_technology
     
  4. Dr. Strangelove

    Dr. Strangelove New Member

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    I still don't understand why people are so worried about size???

    Who cares if it is the size of a shoebox, if it is XXXX number of times more powerful than what we have now. With single photons being the driving force there is probably next to no heat development within the "CPU". And with photons travelling at the speed of light (literally), distance within the chip will probably not matter much either....

    -Jacob
     
  5. Dr. Strangelove

    Dr. Strangelove New Member

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    ups... double post
     
  6. edzieba

    edzieba Virtual Realist

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    Air. Or maybe tissue paper? Even if the entirety of the power input was emitted as raw gamma output (rather than the more likely waste heat and other lower energy photons) 100W of gamma radiation emitted omnidirectionally isn't going to do squat unless you enjoy holding your head inside the chassis while using your computer.

    What idiot would build a CPU with graphene? It's not a very good semiconductor at all. What is is excellent at is in other sorts of microelectronics like power amplifiers, and it's useful mechanical and structural properties.

    Complaining Graphene is no good for CPUs is like complaining Carbon Fibre is no good for making windows. Technically correct, but missing the point somewhat.
     
  7. Corky42

    Corky42 Where's walle?

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    Graphene is actually a very good conductor of electrons offering nearly no resistance.
    http://en.wikipedia.org/wiki/Graphene#Electronic

    But in its current state it wont be seen in CPU's for decades or more.
    http://www.bit-tech.net/news/hardware/2011/01/21/ibm-graphene-wont-replace-silicon-cpus/1
    From a massive list of problems preventing them being used are.
    1. Graphene does not have an energy gap, and therefore, graphene cannot be “switched off"
    2. Much of the research done on graphene to date has focused on proving basic principles
    3. When the transistor was discovered, in 1947 at Bell Labs, the three scientists working on the problem knew they’d found something big, but refining the first transistor into a marketable product took years
     
  8. ferret141

    ferret141 Well-Known Member

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    3D light processor.......am I the only one reminded of this?

    [​IMG]

    Or this?

    [​IMG]
     
  9. ashchap

    ashchap Member

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    Assume shoebox is 30cm across

    speed of light = 3x10^8 metres per second

    time taken for a photon to travel from one side of the shoebox to the other = 0.3/3x10^8 = 1x10^9 = 1 nanosecond

    1GHz clock cycle = 1 nanosecond

    so you could not run the processor faster than 1GHZ without having serious syncronization problems.


    Nitpicking, but light's status as being both a wave and a particle isn't odd. All particles are waves. All waves are particles. Light is nothing special in that respect, it just has a low enough energy that we can easily observe the wave behaviour.
     
  10. Corky42

    Corky42 Where's walle?

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    @Ashchap, you are mixing up what is used to generate the photon with what is used to do the switching, we don't measure the distance a electron has to travel from the PSU.
    If they used X-rays the distance inside the transistor a photon would travel would be between 0.01 to 10 nm
     
  11. ashchap

    ashchap Member

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    Agreed, but my point was that if you have one transistor on one side of the CPU that needs to send a signal to another transistor on the other side of the CPU then how long will it take for the information to get there? answer: (at least) the distance between them divided by the speed of light. If the clock cycle is over before an operation can physically be completed then you are going to have problems.
     
  12. lacuna

    lacuna Member

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    Coincidentally, I was reading Congo (Micheal Crichton) last week and this concept was discussed in there and that was back in the early 80's. Apparently its taken quite a while to realise.
     
  13. Corky42

    Corky42 Where's walle?

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    Less time than current CPU's take to do the same thing, the main advantage of using photons vs electrons is the reduction in size and heat, i think :confused:
     
  14. siliconfanatic

    siliconfanatic Johny-come-Lately

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    Ferret: loved the avengers. Best reference ever, but good point. Tesseract=arc reactor. :D
     

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