Analysis of the characteristics of a pulsed chemical DF-CO2 laser under lasing and amplification conditions

Experimental and calculated data are used in an analysis of the characteristics of a pulsed chemical DF–CO₂ laser under free-running and amplification regimes. A deviation of the distribution of the populations of the vibrational states of the CO₂ molecule from the Boltzmann law was observed in the course of amplification of a saturating 150-nsec pulse. The role of a "hot" R 23 (01¹1–11¹0) transition and the influence of rotational relaxation on the kinetics of lasing of individual vibrational—rotational lines, on the output radiation pulse profile, and on the output energy were considered. The calculated and experimental values of the unsaturated gain and of the output energy in the free-running regime were in good agreement when the degree of initiation (dissociation) was far from the lasing threshold.