back to article Three photons can switch an optical beam at 500 GHz

American photonics researchers have demonstrated an all-optical switching rig that can work at 500 GHz, controlling a beam using just three photons. High-speed switching in the optical domain is important for several reasons: it will let optical networks outperform anything that can be accomplished if the photonic signal has …

  1. Adam 1 Silver badge

    If my math is right, that is less than a second to transmit a blu ray disc. Not bad. When can we have a real NBN?

  2. John Smith 19 Gold badge
    Thumb Up


    Just to put this in perspective.

    Usual IR frequency used for fibre is equal to about 1eV.

    so 3eV of control energy switch 1W or 1 J/s

    3eV is about 5 x 10^-19 J

    IE a signal 2 billion billion times bigger.

    Which is quite impressive.

    1. Frank Rysanek

      Re: Awsome.

      At this switching speed and gain... wouldn't it be an interesting building block for all-optical processors? Actually I can imagine why NOT: no way to miniaturize this to a level competitive with today's CMOS lithography.

  3. Robert Ramsay


    ...what happens if any of the three photons falls out and rolls under the sofa?

    1. Adam 1 Silver badge

      Re: But...

      They would never see the light of day again?

      /here all week

    2. intrigid

      Re: But...

      Auto failover to backup token ring, obviously.

  4. Adam 1 Silver badge

    Three photons walk into a bar. The bartender asked "three lights?"

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