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Simple Mod Turns Diodes Into Photon Counters

Posted by timothy on from the measure-once-vote-often dept.

KentuckyFC writes "The standard way to detect single photons is to use an avalanche photodiode in which a single photon can trigger an avalanche of current. These devices have an important drawback, however. They cannot distinguish the arrival of a single photon from the simultaneous arrival of two or more. But a team of physicists in the UK has found a simple mod that turns avalanche photodiodes into photon counters. They say that in the first instants after the avalanche forms, its current is proportional to the number of photons that have struck. All you have to do is measure it at this early stage. That's like turning a Fiat 500 into a Ferrari. Photon counting is one of the enabling technologies behind optical quantum computing. A number of schemes are known in which it is necessary to count the arrival of 0, 1 or 2 photons at specific detectors (abstract). With such a cheap detector now available (as well as decent photon guns), we could see dramatic progress in this field in the coming months."

7 of 118 comments (clear)

  1. Down already? by DrLudicrous · · Score: 0, Offtopic

    Instantaneously slashdotted site?

  2. Slashdot is dying a prolonged death by Anonymous Coward · · Score: -1, Offtopic

    Netcraft confirms it!

    Do old nerd sites go to heaven when death comes, or is it a drop off the face of the earth into nothingness thing?

    I need to know!

  3. WTF is a Fiat 500? by Anonymous Coward · · Score: -1, Offtopic

    And if it's that bad, is the Fiat 400 even worse?

  4. Going compact by smittyoneeach · · Score: -1, Offtopic

    Felling the photons
    By fives, sevens, fives again
    Is like Burma Shave

    --
    Get thee glass eyes, and, like a scurvy politician, seem to see things thou dost not.--King Lear
  5. To burn some karma by ericrost · · Score: -1, Offtopic

    What is the deal with the new tree system since the theme change? I constantly have issues with deeply nested comments that I click on a reply to a comment I'm reading and end up viewing a completely unrelated comment. I just don't think this is a successful "upgrade" to the discussion system. I end up having to click on the post numbers and navigating that way, which is annoying!

    --
    My Babylon
    1. Re:To burn some karma by Finallyjoined!!! · · Score: -1, Offtopic

      Agree. Also the stupid advert on the front page (have to use Exploder 7 at work) completely covers the article, rendering it unreadable. Bah.

      --
      If I had an Ass, I'd call it Fanny Bottom, then I could slap my Ass; Fanny Bottom, on the Arse.
  6. Re:Ability to count 1,2,3 photons... by fyngyrz · · Score: 0, Offtopic

    You gotta love slashdot's moderation. Of course a post about how you might use the precise technology brought up by an article is off-topic. Of course it is.

    This is why letting any idiot moderate is a bad idea. Inevitably, you get idiots moderating. :-) This is also why you have to read slashdot at -1; moderation as a filter is pathologically unfit for use by sensible readers.

    --
    I've fallen off your lawn, and I can't get up.