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Amplitude - photon correspondence

  1. Nov 12, 2011 #1

    I've got a number of questions about physics. None of my physics friends have given me clearly defined answers, so I thought maybe asking here.
    For now, I'll just ask one simple question.

    So, if I have a laser pointer, which has a weak battery, it will shine with less number of photons than if I had a strong battery. Correct? The only difference, with a strong battery, would be more photons. Correct?
    If you look at the laser pointer's electromagnetic light wave the change you would see, with the stronger battery, is that the amplitude of the wave increased.

    If this is the case, then there is a correspondence between the number of photons, and the amplitude of the light wave.
    Meaning that each photo corresponds to a specific amount of amplitude.
    Do you know what this specific amount of amplitude per photon?

    Thank you,
  2. jcsd
  3. Nov 12, 2011 #2


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    Science Advisor
    Gold Member

    You can make a rough estimate.

    Take the energy in the wave, call it W (it should be proportional to the square of the electric field E), and then take the energy of one photon = hf, and divide the two: W/hf.
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