Broadening of rovibrational absorption lines of carbon monoxide and dioxide molecules as a result of collisions with walls

The mechanisms determining the absorption line profiles of CO and S{cyrillic}O{cyrillic} ₂ molecules enclosed in cells with sizes changing from a few tens of nanometers to a few centimeters are considered. Frequencies of molecular transitions from several reciprocal centimeters (rotational transitions) to 2000 cm ^-1 (rovibrational transitions) are considered. Doppler and intermolecular collisional broadening and line broadening as a result of collisions with walls of the cell filled with the gas are discussed. It is demonstrated that the contribution of line broadening as a result of collisions with cell walls to the total line width can change from several fractions to several tens of percent depending on the cell size. The temperature dependence of the contributions of line broadening and their dependence on the absorption wavelength are discussed.