Nonequilibrium kinetics of coupled photons and electrons in twolevel systems of the laser type
Abstract
Rate equations for photons and for electrons in systems of two groups of energy levels are set up allowing for absorption, stimulated and spontaneous emission, nonradiative transitions, photon loss or dissipation as well as photon gain from the ambient, and an externally applied pumping rate. The rate equations are discussed qualitatively, and the stability of the solutions is obtained by the use of phase portraits. The quantitative discussion includes steadystate photon distributions. Earlier work showing that these distributions can obey the BoseEinstein law with a nonzero chemical potential kTF is taken into the laser regime, which was not covered by recent relevant work. The secondorder phase transition that occurs at threshold is established explicitly, and it is shown that the transition requires the neglect of certain generation terms in the rate equations. Some timedependent solutions of the rate equations are also discussed, using the slaving principle of adiabatic elimination for the electrons. The application of this work to semiconductors is discussed.
 Publication:

Journal of the Optical Society of America (19171983)
 Pub Date:
 September 1983
 Bibcode:
 1983JOSA...73.1197S
 Keywords:

 Electron Transitions;
 Nonequilibrium Conditions;
 PhotonElectron Interaction;
 Reaction Kinetics;
 Semiconductor Lasers;
 Stimulated Emission;
 Atomic Energy Levels;
 Photoabsorption;
 Quantum Mechanics;
 Radiant Flux Density;
 Spontaneous Emission;
 Lasers and Masers