Open AccessOptical cavity enhanced real-time absorption spectroscopy of CO2 using laser amplitude modulation
Author(s) -
Jiahao Dong,
Timothy T.-Y. Lam,
Malcolm B. Gray,
R. B. Warrington,
Edward H. Roberts,
D. A. Shaddock,
D. E. McClelland,
J. H. Chow
Publication year - 2014
Publication title -
applied physics letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.182
H-Index - 442
eISSN - 1077-3118
pISSN - 0003-6951
DOI - 10.1063/1.4892535
Subject(s) - spectrometer , laser , tunable diode laser absorption spectroscopy , absorption (acoustics) , finesse , spectroscopy , absorption spectroscopy , materials science , analytical chemistry (journal) , optics , amplitude , cavity ring down spectroscopy , duty cycle , optical cavity , amplitude modulation , fabry–pérot interferometer , chemistry , tunable laser , frequency modulation , radio frequency , physics , telecommunications , power (physics) , chromatography , quantum mechanics , computer science
We present a spectrometer based on the cavity enhanced amplitude modulated laser absorption spectroscopy (CEAMLAS) technique for measuring molecular gas absorption. This CEAMLAS spectrometer accurately measured a CO2 absorption line at 1572.992 nm with effectively 100% measurement duty cycle. It achieved an absorption sensitivity of 5.2 × 10−9 Hz−1∕2 using a linear Fabry-Perot cavity with a modest finesse of ≈1000. We also used the spectrometer to perform preliminary measurements of the 13C/12C isotopic ratio in CO2, yielding an isotopic signature δ13C of −83±9‰ for our CO2 sample.
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