Dynamics of a System of N Atoms Interacting With a Radiation Field

The time-dependent behavior of an idealized laser is analyzed. The analysis avoids the use of the rate equations and includes $N$-particle "superradiant" effects. Perturbation theory is not used; the dynamics of $N$ two-level atoms interacting strongly with a single-radiation field mode yields four coupled nonlinear equations which are integrated numerically for some special cases appropriate to lasers operating under ordinary power output as well as "$Q$-spoiling" conditions. Loss effects are grafted onto the dynamical equations phenomenologically. It is seen that under appropriate conditions, the laser is expected to emit one or more appreciable subsequent output bursts following an initial giant pulse, and that the subsequent emissions may be emitted by a population which is below inversion.