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Semiconductor lasers

  1. May 18, 2010 #1
    Hi, I want to know what the important quantitative differences between the light produced by an atomic gas laser and that produced by a semiconductor laser are?

    I know that produced my atomic gas lasers are low power but high collimation, but semiconductor lasers seem to have higher power? because of stimulated emission?

  2. jcsd
  3. May 21, 2010 #2
    You cannot distinguish the light of the two lasers. The properties are mostly set by the cavity. The main difference is, that there is no spectral or spacial hole burning in gas lasers because the particles are moving around.
  4. May 21, 2010 #3
    The coherence properties of a diade and a gas lasers differ quite a lot. The coherence length of a laser diode is around 1 mm whilst a gas laser can extend tens of meters
  5. May 21, 2010 #4


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    Diode lasers can have reasonable coherence lengths (few 10s cm) but are very temperature sensitive, you can also have problems if any of the light is scattered back into the diode.

    Traditionally if you wanted high power you needed gas lasers, but engineering convenience means that people have developed few x 10KW diode lasers for cutting/welding
    For all you want to know about lasers see http://www.repairfaq.org/sam/laserdio.htm
    Last edited: May 22, 2010
  6. May 22, 2010 #5
    If you need raw power nothing (almost) beats a good diode array. Unfortunately, diode lasers don't easily provide some other desirable characteristics: good beam quality, low divergence, long coherence length.
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