Transients in a far-infrared laser

Abstract
The transient behavior of an optically pumped, monomode, far-infrared laser is investigated with the use of on-off switching of the pump power. Various regimes of the onset of laser action are observed and described with the use of a two-level model for the lasing medium. At low pressures there is a possibility of undamped oscillation for the output power, which is assigned to a competition between two fields. The transients observed as the pump power is switched off are explained with the use of a three-level model.