Experimental Study and Simulation of Singlet-Triplet Rovibronic Ozone Bands in the 11 900–12 800 cm−1 Region

A compact absorption spectrometer with a narrowband continuous tunable diode laser is created; it provides sensitivity on the order of 1 × 10⁻⁶ cm⁻¹ in terms of the absorption coefficient. The design of the spectrometer, the measurement technique, and the ozone generation and control procedure are described. The absorption spectrum of the ozone molecule is recorded for a system of Wulf bands in the near-IR range 11 900–12 800 cm⁻¹, which correspond to rovibronic transitions from the ground to excited triplet electronic states above the main dissociation threshold of the molecule. The absorption coefficient is simulated and predissociation broadening of spectral lines is estimated in the spectral range under study based on the simulation results. Ozone absorption cross sections in this range are recommended for atmospheric applications; they have been derived using statistically weighted averaging of the new measurements and published laboratory experimental data.