Investigation of the optical homogeneity of the active medium of an atmospheric-pressure electron-beamcontrolled CO2 laser during stimulated emission

An investigation was made of the optical homogeneity of the active medium of an electron-beam-controlled CO₂ laser at the moment of emission of a pulse. Inhomogeneities due to the dependence of the rate of thermal relaxation of the vibrational levels of the CO₂ molecules on the power of the laser radiation extracted from the excited region were observed experimentally. It was found that the resultant fluctuations of the refractive index at the edge of a laser beam amounted to 3×10^–6. It was also observed that when the structure of the radiation field was jagged, similar inhomogeneities could appear not only at the edge of a laser beam but throughout the active medium occupied by the radiation.