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Direction taken by photons

  1. Jul 29, 2011 #1
    sorry my english I am french. :)

    So I was wondering whats the direction of light?
    I understand light is composed of photons and those are released when electrons
    change orbit.
    But if 10 000 photons are released what direction will they take and why ?
    Tell me if Im wrong about some stuff (i am new to this)
  2. jcsd
  3. Jul 29, 2011 #2
    The light emitted by an orbital transition in general is not correlated spatially in a free atom. This means that the light is free to be emitted in any general direction, and that the "average" of the directions of emitted photons should be zero.

    Since the spontaneous emission of a photon after excitation is a statistical property, with a statistical lifetime, the conditions of the atom, such as it's position, orientation etc can affect the direction of the emitted photon, if you wish to think about it in this way.

    However, there are ways you can induce an atom to emit in a specific direction, with a particular polarization etc, and to get a group of atoms to emit their photons in the same direction. This is how a laser is created.
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