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arXiv · 2608.10508

Benchmark measurements of absolute frequencies and collisional line-shape parameters in the CO-Ar system using comb-based FTS

Akiko Nishiyama·Grzegorz Kowzan·Dominik Charczun·Roman Ciuryło·Piotr Masłowski
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Abstract

We report absolute frequency measurements of the CO fundamental band, together with high-precision Ar-induced collisional line-shape parameters using comb-based Fourier-transform spectroscopy. High-quality spectra were obtained with a stable mid-IR optical frequency comb source and careful suppression of technical noise. By applying analysis methods that fully exploit the advantages of optical frequency comb spectroscopy, precise frequency calibration and robust multi-line fitting were achieved, resulting line-center fitting errors below 0.00001 cm$^{-1}$ for most transitions. The measured transition frequencies agree with HITRAN within 0.0001 cm$^{-1}$, supporting the reliability of the semi-empirical database. Multi-line fits using a speed-dependent Voigt profile yield collisional parameters for approximately 40 P- and R-branch lines, providing a reliable experimental benchmark for CO-Ar line-shape modeling.

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Akiko Nishiyama, Grzegorz Kowzan, Dominik Charczun, Roman Ciuryło, Piotr Masłowski. 2026-08-11. Benchmark measurements of absolute frequencies and collisional line-shape parameters in the CO-Ar system using comb-based FTS. https://arxiv.org/abs/2608.10508

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