Absolute frequency measurements of CO2 transitions at 4.3 μm with a comb-referenced quantum cascade laser
Authors: Galli I., Bartalini S., Cancio P., Cappelli F., Giusfredi G., Mazzotti D., Akikusa N., Yamanishi M., De Natale P.
Autors Affiliation: Istituto Nazionale di Ottica (INO) – CNR and European Laboratory for Nonlinear Spectroscopy (LENS) , Sesto Fiorentino , FI , Italy; Development Bureau Laser Device R&D Group, Hamamatsu Photonics KK , Shizuoka , Japan; Central Research Laboratories, Hamamatsu Photonics KK , Shizuoka , Japan
Abstract: The infrared spectrum of the (0111–0110) ro-vibrational band of 12C16O2 in the range 2306–2312 cm−1 is investigated with saturated-absorption sub-Doppler spectroscopy. The absolute frequencies of six transitions belonging to the P-branch of this band are measured by recording their Lamb-dip features in a pump-probe detection scheme employing a room-temperature quantum cascade laser. The laser is phase-locked to a subkilohertz-linewidth difference-frequency-generated radiation source, which is referenced to an optical frequency comb synthesiser. The achieved relative uncertainties range from 1×10−11 to 5×10−11, improving by three to four orders of magnitude the previous tabulated values for such frequencies. Moreover, thanks to this precision level, self-pressure-shift coefficients due to collisional processes of CO2 molecules are reported for the first time.
Journal/Review: MOLECULAR PHYSICS
Volume: 111 Pages from: 2041 to: 2045
More Information: We wish to thank Prof. Gianfranco Di Lonardo for his valuable help in finding the most accurate calculated frequencies of our observed transitions. This work was financially supported by Ente Cassa di Risparmio di Firenze, by the Laserlab-Europe Consortium in the ALADIN project framework, by the Extreme Light Infrastructure (ELI) European project and by the Progetto Operativo Nazionale (PON) PON01 01525 MONitoraggio Innovativo per le Coste e l\’Ambiente marino\’ (MONICA) funded by the Italian Ministry of Education, University and Research (MIUR).KeyWords: Absolute frequency measurements; Difference frequency; Lamb dip; Optical frequency combs; Orders of magnitude; Relative uncertainty; Saturated-absorption spectroscopy; Sub-Doppler spectroscopy, Laser mode locking; Natural frequencies; Optical materials; Quantum cascade lasers, Carbon dioxideDOI: 10.1080/00268976.2013.782436Citations: 15data from “WEB OF SCIENCE” (of Thomson Reuters) are update at: 2020-09-13References taken from IsiWeb of Knowledge: (subscribers only)Connecting to view paper tab on IsiWeb: Click hereConnecting to view citations from IsiWeb: Click here