Direct Comb Vernier Spectroscopy for Fractional Isotopic Ratio Determinations

Year: 2021

Authors: Siciliani de Cumis M., Eramo R., Jiang J., Fermann M.E., Pastor P.C.

Autors Affiliation: Agenzia Spaziale Italiana, Contrada Terlecchia SNC, Matera, 75100, Italy; Istituto Nazionale di Ottica, INO-CNR, Via N. Carrara 1, Sesto Fiorentino, 50019, Italy; Dipartimento di Fisica, Universitb degli Studi di Firenze, Via G. Sansone 1, Sesto Fiorentino, 50019, Italy; IMRA America, Inc., 1044 Woodridge Avenue, Ann Arbor, 48105, MI, United States

Abstract: Accurate isotopic composition analysis of the greenhouse-gasses emitted in the atmosphere is an important step to mitigate global climate warnings. Optical frequency comb-based spectroscopic techniques have shown ideal performance to accomplish the simultaneous monitoring of the different isotope substituted species of such gases. The capabilities of one such technique, namely, direct comb Vernier spectroscopy, to determine the fractional isotopic ratio composition are discussed. This technique combines interferometric filtering of the comb source in a Fabry-Perot that contains the sample gas, with a high resolution dispersion spectrometer to resolve the spectral content of each interacting frequency inside of the Fabry-Perot. Following this methodology, simultaneous spectra of ro-vibrational transitions of (CO2)-C-12-O-16 and (CO2)-C-13-O-16 molecules are recorded and analyzed with an accurate fitting procedure. Fractional isotopic ratio C-13/C-12 at 3% of precision is measured for a sample of CO2 gas, showing the potentialities of the technique for all isotopic-related applications of this important pollutant.

Journal/Review: SENSORS (BASEL)

Volume: 21 (17)      Pages from: 5883-1  to: 5883-12

More Information: This research was funded by the project Extreme Light Infrastructure-Italy (ELI-Italy) and by the QOMBS project (FET Flagship on Quantum Technologies grant No. 820419).
KeyWords: isotopic ratio; frequency comb; Vernier spectroscopy
DOI: 10.3390/s21175883