Q-branch shapes of CO2 spectrum in 15 μm region: Experiment

Abstract The shapes of Q -branches in CO 2 spectra in the 580–850 cm −1 region for pure gas and mixtures CO 2 He and CO 2 Ar have been studied at resolutions up to 0.002cm −1 . The branch broadening coefficients were measured in the pressure range from a few torr to 50 atm. Those for 11 1 02-02 2 01 Π-Δ transition are different for pressures below and above 5 atm. At higher pressures the branch broadening coefficients are similar for all Q -branches. The observed Q -branch shape transformation is explained by line mixing effects.