Detection and analysis of three highly excited vibrational bands of 16O3 by CW-CRDS near the dissociation threshold

•Cavity ring down spectroscopy of 16O3 between 7600 and 7920 cm−1.•531 Transitions assigned to three vibrational bands.•Upper vibrational states located only a few % below the dissociation limit.•Effective operator modelling of the spectra.•Good agreement with ab initio values for the band centres and rotational constants.

The present contribution is devoted to the analysis of three extremely weak A-type bands of 16O3 recorded near 7686, 7739 and 7860 cm−1i.e. only a few % below the dissociation limit, D0, at about 8560 cm−1. They correspond to the most excited vibration-rotation states of ozone observed so far via high-resolution absorption spectroscopy. They were detected by high sensitivity CW-cavity ring down spectroscopy with a typical noise equivalent absorption, αmin, on the order of 2×10−10 cm−1 and modelled using the effective operator approach. The derived band centres and rotational constants show a very good agreement with recent theoretical predictions based on a new ab initio potential energy surface.