Sensitive detection of methane and nitrous oxide isotopomers using a continuous wave quantum cascade laser
Publication information:
Gagliardi, Tamassia, De Natale, Gmachl, Capasso, DL Sivco, JN Baillargeon, AL Hutchinson, and AY Cho. 2002. “Sensitive Detection of Methane and Nitrous Oxide Isotopomers Using a Continuous Wave Quantum Cascade Laser”. EUROPEAN PHYSICAL JOURNAL D, 19, 3, Pp. 327-31. doi:10.1140/epjd/e20020091
Abstract
A continuous wave quantum cascade laser (QCL), operating near 8.1 mum, was used for wavelength modulation spectroscopy of methane (CH4) and nitrous oxide (N2O) stable isotopes. Several rotational transitions of (N2O)-N-14-O-16, (NNO)-N-15-N-14-O-16, (N2O)-N-14-O-18, (N2O)-N-14-O-17, (CH4)-C-13 and (CH4)-C-12 fundamental bands were detected. The noise-equivalent absorbance was measured to be less than 10(-5) in a 1-Hz bandwidth. A characterization of the laser source was also performed. The use of a QCL spectrometer for high-precision isotope ratio measurements is discussed.