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Methods of tunable diode laser absorption saturation spectroscopy to gas sensing under optically thick conditions
Author(s) -
Nie Wei,
Xu Zhenyu,
Rao Gangfu,
Lin Xiao,
Lu Jidong,
Dong Meirong,
Kan Ruifeng
Publication year - 2021
Publication title -
microwave and optical technology letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.304
H-Index - 76
eISSN - 1098-2760
pISSN - 0895-2477
DOI - 10.1002/mop.32840
Subject(s) - tunable diode laser absorption spectroscopy , saturation (graph theory) , absorption spectroscopy , laser , materials science , spectroscopy , absorption (acoustics) , optics , methane , diode , optoelectronics , analytical chemistry (journal) , tunable laser , chemistry , wavelength , physics , mathematics , organic chemistry , chromatography , combinatorics , quantum mechanics , composite material
The absorption saturation under optically thick conditions will bring difficulties to laser spectroscopy gas sensing. We report the spectrum two wings reconstruction method and the transmitted laser intensity fitting method for tunable diode laser absorption saturation spectroscopy gas absolute measurements under optically thick conditions, and used the modified Lambert Beer's law to calculate methane concentration based on the incomplete spectrum of absorption saturation. The maximum deviation between the experimental measurement results and the standard methane concentration is about 4.7%, which verifies the feasibility of these new methods and also show that they have great potential for expanding the gas sensing range of a single absorption line.