Investigation of physical processes in the active medium of a pulsed CO2 laser responsible for variation of the laser frequency during a pulse

An investigation was made of the physical processes occurring in the active medium of a pulsed CO₂ laser and responsible for variation of the laser frequency during a pulse. The processes considered were inhomogeneous deposition of the input energy, influence of free electrons, and self-interaction of the laser radiation. It was found that free electrons and the self-interaction provided the main contribution to the frequency variation. Some of the results differed from those described in the literature. The reasons for the discrepancy are discussed.