Abstract

The diode laser spectrometer operating in the 4.5 μm region with a spectral resolution of about 10^-4cm^-1 was applied to investigate the active medium of a DC-excited fast-axial-flow CO₂ laser. Detailed distributions of the CO₂ molecules over the rotational and vibrational levels in a glow discharge plasma have been obtained, and corresponding temperatures have been derived. The vibrational distribution involves more than 30 levels from all vibrational modes of CO₂. The bending and symmetric stretch temperatures were found to be equal, and approximately equal (within experimental error of 2-4%) to the rotational temperature.

© 1995 Optical Society of America