Spectral shape parameters of pure CO2 transitions near 1.6 µm by tunable diode laser spectroscopy

•Spectra of 4 lines of pure CO2 in the 1.6 μm region have been measured by TDLS•A multi-spectrum fitting procedure with various line-shape models have been used for the analysis•The results show that the Dicke narrowing and speed-dependence effects are clearly observed.•The HT model leads to the best agreement with measurements and physically-based parameters

Room temperature spectra of four lines of pure CO2 in the 1.6 μm region have been measured in a wide range of pressure using a tunable diode laser spectrometer. The spectra of each line have been adjusted using a multi-spectrum fitting procedure with various line-shape models, including the recently recommended Hartmann-Tran profile (HTP). The results show that the collision-induced velocity changes and the speed-dependence effects are clearly observed. It is also shown that taking into account the correlation between velocity- and internal state-changes is necessary to obtain physically-meaningful line-shape parameters. The latter are reported and discussed.