Some features of the mechanism of formation of optical inhomogeneities in CO lasers

A theoretical analysis is made of a mechanism of a thermal nonlinearity of the active medium of CO lasers. It is shown that the thermal nonlinearity is mainly due to vibrational-vibrational exchange involving anharmonic CO molecules. The nonlinear heat release dynamics is determined and an estimate is made of the angular aberrations of optical beams caused by nonlinear optical inhomogeneities. The results are compared with the corresponding data for CO₂ lasers.