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Electron absorbs photons

  1. Feb 5, 2013 #1
    Hello all

    Is that possible a electron absorbs two photons at the same time to jump to a higher energy level and then emission one higher energy photon and back to before level ?

    example : electron absorbs 2 photon by energy 10 and 20 eV and jump up from 2 to 3 energy level and emission a 30 eV photon and back to 2 energy level ?
  2. jcsd
  3. Feb 5, 2013 #2
    Yes, it is possible.
    The energy difference from the electron in its ground state and excited state corresponds to the sum of the two photon energies.
    Last edited: Feb 5, 2013
  4. Feb 5, 2013 #3
    I didn't see in any reference that said a electron can absorbs six or ten photons at same time and emission one equal photon .
    Do you see in any reference ?
  5. Feb 5, 2013 #4


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    Staff: Mentor

    You were asking about two photons before. Why are you now asking about six or ten?
  6. Feb 6, 2013 #5


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    Science Advisor

    Are five photons sufficient? Right now in the advanced online publication of Nature Photonics:
    "Frequency-upconverted stimulated emission by simultaneous five-photon absorption" by Q. Zheng et al. (Nature Photonics (2013) doi:10.1038/nphoton.2012.344). Not an electron, but a fluorophore, but I suppose the concept is what matters.

    And yes, in principle that works also for higher photon numbers, but please do not ask for a reference about 347-photon absorption.
  7. Feb 6, 2013 #6


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    According to the details of the QED formalism = Feynman rules it's not possible at the same time b/c there is no vertex with two photon lines.
  8. Feb 6, 2013 #7
    Because my purpose and my main question was that can electron absorbs many photons and release a equal photon ? and i think maybe my question was unclear . sorry for my English

    Number is not important for me !
    I want to know electron can absorbs several photons at the same time and emission one equal photon .
    if a electron can absorbs two photon why not absorbs 6 or 347 or .... ?
  9. Feb 6, 2013 #8
    How about at several time ?

    example : electron absorbs one photon and jump from first to second level energy and then absorbs another photon and jump from second to third level and then absorbs another photon and jumps to fourth level and then emission one equal photon and back to first level ? is that possible ?
  10. Feb 6, 2013 #9
    You need to try to ask your questions a bit more specifically. I'm guessing that you are talking about an electron that is bound to an atom right? In this case two-photon absorption is possible (and higher order as well), see for example the wiki page: http://en.wikipedia.org/wiki/Two-photon_absorption. The main restriction which may limit multiple photon absorption events in atoms is conservation of angular momentum/spin. But as long as that is fullfilled (together with energy conservation) there is no reason why they can't happen. Just note that higher order processes are more unlikely.
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