Frequency-stabilized cavity ring-down spectroscopy (FS-CRDS) was employed to measure over 100 transitions in the R-branch of the b1Σg+←X3Σg-(0,0) band for the rare O2 isotopologues. The use of 17O- and 18O-enriched mixtures allowed for line positions to be measured for the 16O17O, 16O18O, 17O2, 17O18O, and 18O2 isotopologues. Simultaneous fits to the upper and lower states were performed for each isotopologue using the FS-CRDS positions supplemented by microwave, millimeter, submillimeter, terahertz, and Raman ground state positions from the literature. Positions, line intensities, pressure broadening parameters, and collisional narrowing parameters are reported for the 16O18O and 16O17O isotopologues which are based upon the present study and our earlier FS-CRDS work (Long et al., JQSRT, 111, 2021 and Robichaud et al., JPCA, 113, 13089). The calculated line intensities include a term for the observed Herman-Wallis-like interaction and correct a frequency-dependent error which is present in existing spectroscopic databases.
Citation: Journal of Quantitative Spectroscopy and Radiative Transfer
Pub Type: Journals
Oxygen, A-band, Cavity ring-down spectroscopy, Remote Sensing, Isotopologue, Galatry profile.