3 ms·

Does stimulated emission hold this property? We increase the energy until the system lases but the entropy decreases as the gain narrows?

• jpdoctor 14y ago
  > Does stimulated emission hold this property? Yes. > We increase the energy until the system lases but the entropy decreases as the gain narrows? Typical model is the two level system. At abs 0+, all the electrons are in the lower state. at abs 0-, all the electrons are in the upper state.
  • frozenport 14y ago
    So are the photons in a laser at a negative temperature.
    • jpdoctor 14y ago
      No. The photon population is not in thermal equilibrium. (They are concentrated at one energy, rather than obeying the Bose-Einstein distribution vs energy.) More generally: A negative absolute temperature is possible only when the distribution of energy states is bounded by some maximum.