Dynamics of the CO₂ Atmospheric Pressure Laser with Transverse Pulse Excitation

Abstract

The dynamical processes responsible for laser emission in the pulsed pumping of a transversely excited atmospheric (TEA) CO 2 laser are investigated. An explanation for the formation of the giant pulse is proposed on the basis of a gain-switching mechanism in which it is assumed that with short strong-current pulses a high population inversion can be achieved prior to the onset of laser action. The kinetics of the mechanism are described by means of a set of nonlinear rate equations idealized to a four-energy-state system. With suitable initial conditions on the populations, the transient solution of these equations for the mixtures CO 2 –He and CO–N 2 –He appears to be consistent with the major features of experimental observation.