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Scientists Freeze Pulse Of Light

Posted by simoniker on from the mr-bigglesworth-looks-on dept.

Smitty825 writes "After slowing down light to slow speeds, scientists at Harvard University have been able to stop light for a very brief period of time without destroying its energy. The article explains how it is different from this previous light-stopping science story - this will hopefully help the development of quantum computers and ways to communicate over long distances without being eavesdropped on."

6 of 343 comments (clear)

  1. Apparently, there is energy loss by ultraw · · Score: 5, Informative

    The article mentions clearly:

    "We have succeeded in holding a light pulse still without taking all the energy away from it," said Mikhail D. Lukin, a Harvard physicist.

    This is somehow different from "...without destroying its energy." like it is stated in the posting. Maybe a subtle detail, but not quite the same.

    However, a briliant achievement. Kuddos.

  2. Well you could have found it by loadquo · · Score: 5, Informative

    Like I did here.

  3. More links by prospero14 · · Score: 5, Informative

    More detailed articles about the research can be found here or here.

    Larkin's article itself is here.

    Any physics nerds want to explain it to us?

    1. Re:More links by Zog+The+Undeniable · · Score: 5, Informative

      The light beam is stored (in gas atoms) rather than stopped. It's a bit like sending an e-mail - you don't get the same electrons that were sent to you from the other person's computer, but the electrons that come down your telephone line/DSL/cable are identical in every respect.

      --
      When I am king, you will be first against the wall.
  4. Re:Interesting note/errata by benjamindees · · Score: 5, Informative

    That may be how traditional optical communications works. Quantum crypto, otoh, relies on the light being put in a certain polarization state by the sender. It's designed so that a stream of single photons go from sender to receiver; there can be no equipment in-between. If an intermediary views this photon en-route, it disturbs the polarization seen by the receiver. Because of the way the sender and receiver can agree on which photons were correctly measured, any aberrations (intercepted photons) are discarded. The most you can hope for is a denial-of-service.

    Here's a better explanation than I can muster.

    --
    "I assumed blithely that there were no elves out there in the darkness"
  5. Re:Color != frequency by thufir · · Score: 5, Informative

    Sorry friend, but he is correct and you are wrong.

    He stated the 'color' of our photo receptors. Although our photo receptors pick up C, Y, and M -- it is because their colors (as he said) are R, G, and B.

    ie: the Red Photoreceptor reflects RED, that is why it is a red colored photoreceptor. Since it reflects RED, it picks up BLUE and GREEN, which make one of the (secondary) colors you mentioned.

    You are also wrong saying that RGB is used for pigment. Pigment gets its color by absorbing color, and you see what is reflected. RGB is used for TVs and Monitors where there is a direct source of light.

    Cheers!