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How to understand light and mass interaction

  1. Apr 14, 2008 #1
    hi ,everyone

    from the microscopic view, we can simply regard the atom in the mass as a spring, which will be vibrated by the light wave (collided by the photon, could i say that?)and in this way emit some "new" light waves, but whose wavelength is shorter than the incident wave. And it is the reason for the refrective phenomenon. is this true?

    if i am right, why does this "new" light have shorter wavelength ?
    and what has happened to those incident photon that don't collide with the mass atomic since there is large room among the atomics? or there is no photon survie?

    which kind of physical textbook should i read further ,about this area?

  2. jcsd
  3. Apr 14, 2008 #2
  4. Apr 14, 2008 #3
    thank you very much ! genneth. i learn a lot of interesting things from the post you gave
    and could you introduce some deeper textbooks? should i look for a book in quantum, photon area or sth. like that?
  5. Apr 14, 2008 #4
    but in effect, i think, that post was NOT able to answer all my questions.
    and it is not complete itself, the "spring" which absorb and re-emit photons
    should be corelated to not only atomic vibration, but also bipolar vibration in atom itself,
    which is not talked about in the post, disppointly
    i continue to think about it ,waiting for everyone 's help, :-)
  6. Apr 16, 2008 #5
    Raman scattering

    The phenomena you are referring to is Raman scattering (discovered it 1928 by C.V. Raman). When light interacts with a molecule an instantaneous (near-instantaneous) effect occurs where the light is absorbed generally to a virtual state (exciting the molecule) then it relaxes and re-emits a photon. The scattering phenomena is still debated as to whether or not it is a 2 photon effect (absorption then re-emission or not). Most of the time the photon is at the same energy (same wavelength) as the incident light this is known as Rayleigh scattering. However, some of the light is scattered at either a higher energy (shorter wavelength known as anti-Stokes Raman or at a lower energy higher wavelength known as Stokes Raman. As you asked what happens to the photons that don't collide, nothing happens, they continue on their original trajectory. Remember this is a scattering effect in many bulk materials an absorption effect will also be seen.
    There are many texts on Raman scattering and scattering in general. I would start with your basic on line resources (wikipedia, hyper-physics) and google search Raman scattering.
  7. Apr 18, 2008 #6
    yes,Raman is one of the many interactions, but it is not what i wanted to talk about,
    first, Raman and Rayleigh occurs mainly at the IR region, not the UV-Visible
    second, there is a wave frequency (photon energy) shift in Raman effect, which is not the subject I am interested
  8. Apr 18, 2008 #7
    Raman occurs in uv, visible and IR, just depends on your source laser.

    I am not sure what effect you are referring to then.
  9. Apr 22, 2008 #8
    Are you referring to evanescent waves?
  10. Apr 23, 2008 #9
    these days i have read some further textbooks and now i know, what i talked about before was the Lorenz classical model-----"spring" and something like that. and then i didn't understand how to explain all the light phenomena using this model. in the future i will continue to read some materials, thanks for every reply. thank you
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