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CO<sub>2</sub> isotope sensor using a broadband infrared source, a spectrally narrow 4.4 μm quantum cascade detector, and a Fourier spectrometer
Auteur(s)
Di Francesco, Joab F.
Hvozdara, Lubos
Herzig, Hans-Peter
Beck, Mattias
Date Issued
2010
Journal
Applied Physics B: Lasers and Optics, Springer, 2010/103/4/967-970
Abstract
We report a prototype CO<sub>2</sub> gas sensor based on a simple blackbody infrared source and a spectrally narrow quantum cascade detector (QCD). The detector absorption spectrum is centered at 2260 cm<sup>−1</sup> (4.4 μm) and has a full width at half maximum of 200 cm<sup>−1</sup> (25 meV). It covers strong absorption bands of two spectrally overlapping CO<sub>2</sub> isotopomers, namely the P-branch of <sup>12</sup>CO<sub>2</sub> and the R-branch of <sup>13</sup>CO<sub>2</sub>. Acquisition of the spectral information and data treatment were performed in a Fourier transform infrared (FTIR) spectrometer. By flushing its sample compartment either with nitrogen, dry fresh air, ambient air, or human breath, we were able to determine CO<sub>2</sub> concentrations corresponding to the different gas mixtures. A detection limit of 500 ppb was obtained in these experiments.
Publication type
journal article
