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Laser diode principals

  1. May 1, 2014 #1
    As far as I understand, when forward biased voltage applied, electrons from N diffuse to P, then recombine. Since energy gap between conductive electron and hole is const => only certain wavelength photons is emitted.

    In gaseous lasers for example you need to gain a populational inversion, which requires to have a certain energy levels, including one of them to be metastable.

    How the stimulated emission works for laser diodes?
  2. jcsd
  3. May 1, 2014 #2


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  4. May 1, 2014 #3


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    By the way, the formal name for the semiconductor equivalent of population inversion which is discussed in the PDF linked by UltrafastPED is the Bernard-Duraffourg condition. If you need more details, that is the term to look for.
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