Direct Comb Vernier Spectroscopy for Fractional Isotopic Ratio Determinations

Sensors

Mario Siciliani de Cumis¹  Jie Jiang²  Martin E. Fermann²  Roberto Eramo³  Pablo Cancio Pastor³ 

[1] Agenzia Spaziale Italiana, Contrada Terlecchia SNC, 75100 Matera, Italy;IMRA America, Inc., 1044 Woodridge Avenue, Ann Arbor, MI 48105, USA;Istituto Nazionale di Ottica, INO-CNR, Via N. Carrara 1, 50019 Sesto Fiorentino, Italy;

关键词: isotopic ratio;    frequency comb;    Vernier spectroscopy;   

DOI  :  10.3390/s21175883

来源: DOAJ

【 摘 要 】

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 ${}^{12}$C${}^{16}$O${}_2$ and ${}^{13}$C${}^{16}$O${}_2$ molecules are recorded and analyzed with an accurate fitting procedure. Fractional isotopic ratio ${}^{13}$C/${}^{12}$C at 3% of precision is measured for a sample of CO${}_2$ gas, showing the potentialities of the technique for all isotopic-related applications of this important pollutant.

【 授权许可】

Unknown