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Homework Help: Laser pulse calculation - a quick bit of help appreciated

  1. Jan 7, 2006 #1


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    a. A free-running, flashlamp-pumped Nd:YAG laser produced pulses having a duration of 500 microseconds at a repetition frequency of l00Hz. Deduce the pulse power in this type of operation if the average power of the laser is 5W. (100W)​

    b. This laser is then Q-switched and the average power is reduced to 4W. Deduce the peak power of the Q-switched power (2MW)​

    I'm sure this is simple, but I don't seem to be getting the answer I'm supposed to. Anyone care to show how it ought to be done? :smile:


    Last edited: Jan 7, 2006
  2. jcsd
  3. Jan 7, 2006 #2
    Can you show us how far you have come in your calculations?
  4. Jan 7, 2006 #3


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    Yup. I think I've just realised what I was doing wrong as far as part a is concerned.

    Let Pa denote average power
    Let Pp denote power of one pulse
    Let Ep denote energy of one pulse
    Let t denote time of one pulse

    If Pa = 5W, and f = 100Hz, then

    Ep x 100 = 5 => Ep = 0.05
    Pp = Ep / t = 0.05 / (500 x 10^-6) = 100W

    I think that's right. (Hope so).
    Last edited: Jan 7, 2006
  5. Jan 7, 2006 #4


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    I would apply a similar sort of working to the second part. I don't see how it can be done without more information.
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