Measurements of the 3ν3 band of 14N15N16O and 15N14N16O using continuous-wave cavity ring-down spectroscopy

The absorption spectra of the 3ν3 band of nitrous oxide isotopologues, 14N15N16O and 15N14N16O, have been measured using diode laser cavity ring-down spectroscopy in 6400–6463 and 6465–6532 cm-1, respectively. Spectroscopic parameters and the rotational line intensities of the bands have been determined. We have applied this spectroscopic technique to the measurements of the absolute isotope ratio of those isotopologues using the absolute line intensities.