Comb-locked cavity ring-down spectroscopy of CO2 at 2-micron wavelength
Abstract
We report on a comb-locked cavity ring-down spectrometer developed for high-precision, SI-traceable, molecular spectroscopy of air-broadened CO2 gas samples. The experimental setup relies on the use of a singly-resonant optical parametric oscillator that acts as an intermediate link between a 2 micron external-cavity diode laser and an optical frequency comb stabilized against a GPS-disciplined Rb-clock. Absorption spectra of the R(50) ro-vibrational component of the CO2 20012-00001 band have been recorded with high precision and fidelity. As a result of a refined spectral analysis, based on the implementation of the modified Hartmann-Tran profile, line center frequencies, pressure broadening and pressure shifting coefficients have been determined. Finally, we demonstrate the measurement of CO2 mole fractions with a subpromille statistical uncertainty
Keywords
Cite
@article{arxiv.2602.23812,
title = {Comb-locked cavity ring-down spectroscopy of CO2 at 2-micron wavelength},
author = {Muhammad Asad Khan and Vittorio D'Agostino and Stefania Gravina and Livio Gianfrani and Antonio Castrillo},
journal= {arXiv preprint arXiv:2602.23812},
year = {2026}
}