Diagnostics of the active medium of a waveguide CO2 laser by the 'laser spectrograph' method

Abstract

The gains were measured for the lines in the traditional bands 0001–1000, 0001–0200, in the second band of the 0002–1001 sequence, and in the hot band 0111–1110 emitted by the active medium of a waveguide electric-discharge CO2 laser. The experimental results were used in a generalised theoretical model to find the translation and vibrational temperatures, and the concentration of the active molecules. The Fermi resonance between the 1000 and 0200 levels did not ensure a Boltzmann distribution of their populations under the conditions in the waveguide CO2 laser. The degree of dissociation of the CO2 molecules in the discharge did not exceed 30% when the maximum input power density was ~70 W cm-3.