Simultaneous observation of speed dependence and Dicke narrowing for self-perturbed P-branch lines of O2 B band. (December 2021) - Bielska, Katarzyna
Highlights: Oxygen B-band P-branch transitions have updated parameters. Speed-dependence and Dicke narrowing are simultaneously observed. Agreement on line position and intensity between CRDS and CMWS technique. Updated line intensities, up to 3% higher from previously measured. Thermal effects on ring-down cavity mirrors. Abstract: We present new measurements of the oxygen B-band transitions in the P branch performed with the cavity ring-down spectroscopy (CRDS) and the cavity mode-width spectroscopy (CMWS) techniques. Systematic deviations on the line intensities observed comparing to our previously published data are explained. We reached agreement on unperturbed line positions at the 40 kHz level and on the line intensities below 0.2% for measurements performed with the above two techniques. With significantly increased spectra signal-to-noise ratio we simultaneously observe the speed dependence of collisional broadening and shifting as well as Dicke narrowing in the pressure range as low as 1.1 kPa.