Confinement narrowing and absorber speed dependent broadening effects on CO lines in the fundamental band perturbed by Xe, Ar, Ne, He and N-2

Lines of the CO fundamental band are studied at low concentration in He, Ne, Ar, Xe or N-2 as buffer gas from 10 to 600 torr. The coefficient beta(0) associated with the Dicke narrowing effect is determined for each of the five mixtures. To obtain the proper value of this coefficient, when the pressure increases, the absorber speed dependence of the pressure broadening gamma(0) must be taken into account. Pressure shifts are also measured, and a faint asymmetry is observed for the CO-Xe mixture. The line scanning is done with a TDL tightly controlled by a Michelson interferometer. A precision better than one-thousandth for absorbed intensity and a wavenumber precision of a few 10(-5) is reached. These precisions were found necessary for the needed parameter measurements. Copyright (C) 1996 Elsevier Science Ltd