Manifestation of inertiai properties of a medium in the case of single-mode operation of gas lasers

A theoretical approach is developed to describe the operation of a single-mode gas laser in the case when the lifetime of the active levels of the lasing medium is considerably longer than the decay time of the field in the resonator. It is shown that attainment of steady-state operation may be accompanied by oscillations of the mode intensity. A considerable influence of the rate of scanning of the gain profile by a mode on the lasing regime is revealed. It is shown that at some scanning rates the steady-state regime cannot be achieved during the time it takes to pass through the whole frequency range where the gain exceeds the losses, so that lasing is manifested in the form of separate intensity peaks. The results are also reported of an experimental study of a single-mode operation of a CO₂ laser and these results confirm the main theoretical predictions.