title: Low-pressure line-shape study in molecular oxygen with absolute frequency reference.
abstract: We present a line-shape analysis of the rovibronic R1 Q2 transition of the oxygen B band resolved by the Pound-Drever-Hall-locked frequency-stabilized cavity ring-down spectroscopy technique in the low pressure range. The frequency axis of the spectra is linked by the ultra-narrow diode laser to the optical frequency comb in order to measure the absolute frequency at each point of the recorded spectra. Experimental spectra are fitted with various line-shape models: the Voigt profile, the Galatry profile, the Nelkin-Ghatak profile, the speed-dependent Voigt profile, and the speed-dependent Nelkin-Ghatak profile with quadratic and hypergeometric approximations for the speed dependence of collisional broadening and shifting. The influences of Dicke narrowing, speed-dependent effects, and correlation between phase- and velocity-changing collisions on the line shape are investigated. Values of line-shape parameters, including the absolute frequency of the transition 435685.24828(46) GHz, are reported.
authors: Institute of Physics, Faculty of Physics, Astronomy and Informatics, Nicolaus Copernicus University, Grudziadzka 5, 87-100 Torun, Poland.
authors: J
authors: J
authors: Domysławska
authors: S
authors: S
authors: Wójtewicz
authors: A
authors: A
authors: Cygan
authors: K
authors: K
authors: Bielska
authors: D
authors: D
authors: Lisak
authors: P
authors: P
authors: Masłowski
authors: R S
authors: RS
authors: Trawiński
authors: R
authors: R
authors: Ciuryło