Time average formalism for laser pumped lasers
Abstract
It is shown that quantum time averages of the density matrix for a driven but undamped system lead to a physically transparent explanation of steadystate population inversions that occur in certain systems with particular spontaneous emission damping rates. The relevance of a formalism which permits timesmoothed transient solutions to be generated a priori is demonstrated, and equations are derived which extend this development to the case where there are timedependent generated cavity fields. Theoretical results demonstrate lasing without inversion, and this result is discussed in light of the timeaverage treatment. Finally a symbolic manipulation computer code is described which makes it possible to start from limit operations on a certain matrix inverse to enumerate terms in explicit rational expressions for the time average operators, which give the averaged density matrix in terms of its initial values.
 Publication:

Lasers '88; Proceedings of the International Conference
 Pub Date:
 1989
 Bibcode:
 1989lase.conf...24S
 Keywords:

 Formalism;
 Laser Pumping;
 Quantum Theory;
 Spontaneous Emission;
 Laser Cavities;
 Lasing;
 Time Dependence;
 Lasers and Masers