Near-infrared cavity ring-down spectroscopy measurements of nitrous oxide in the (4200)←(0000) and (5000)←(0000) bands

• DOI: 10.1016/j.jqsrt.2021.107527
• Publication Date: 2021-01-20T04:23:08Z
• Authors: Erin M. Adkins; David A. Long; Adam J. Fleisher; Joseph T. Hodges
• Keywords: HITRAN; Voigt profile; Cavity Ring-Down Spectroscopy; Line (geometry); Spectral bands

Using frequency-agile rapid scanning cavity ring-down spectroscopy, we measured line intensities and line shape parameters of 14N2 16O in air in the (4200)←(0000) and (5000)←(0000) bands near 1.6 µm. The absorption spectra were modeled with multi-spectrum fits of Voigt and speed-dependent Voigt profiles. The measured line intensities and air-broadening parameters exhibit deviations of several percent relative to values provided in HITRAN 2016. Our measured intensities for these two bands have relative combined standard uncertainties of ∼1% which is approximately five times smaller than literature values. Comparison of the present air-broadening and speed-dependent broadening parameters to experimental literature values for other rotation-vibration bands of N2O indicates significant differences in magnitude and J-dependence. For applications requiring high spectral fidelity, these results suggest that the assumption of band-independent line shape parameters is not appropriate.