Highly accurate determinations of CO2 line strengths using intensity-stabilized diode laser absorption spectrometry
- 27 August 2007
- journal article
- research article
- Published by AIP Publishing in The Journal of Chemical Physics
- Vol. 127 (8), 084311
- https://doi.org/10.1063/1.2759930
Abstract
An intensity-stabilized laser absorption spectrometer, which incorporates a mirror-extended cavitydiode laser, a temperature-stabilized gas cell, and a Michelson interferometer, was developed and applied to a highly accurate investigation of line intensity factors within the ν 1 + 2 ν 2 0 + ν 3 combination band of carbon dioxide, around 2 μ m wavelength, at a temperature of 296.0 K . This relatively complex apparatus enables one to observe the absorption line shape with high precision and accuracy in such a way that it is possible to retrieve the integrated absorbance with a relative uncertainty better than 0.1%. The absorption spectra were interpolated with the uncorrelated strong-collision model of Rautian and Sobel’man in order to take into account Dicke narrowing effects, thus obtaining an agreement at a level of a few parts per 10 − 5 . We report line strength values for the R ( 2 ) – R ( 18 ) transitions with an unprecedented level of accuracy, in the range between 0.1% and 0.15%. Finally, we discuss the possibility of providing a first experimental test of the theoretical model for molecular line strengths based on the Herman-Wallis expansion.Keywords
This publication has 29 references indexed in Scilit:
- The HITRAN 2004 molecular spectroscopic databaseJournal of Quantitative Spectroscopy and Radiative Transfer, 2005
- Total internal partition sums for molecular species in the 2000 edition of the HITRAN databaseJournal of Quantitative Spectroscopy and Radiative Transfer, 2003
- Combined interferometric and absorption-spectroscopic technique for determining molecular line strengths: Applications toPhysical Review A, 2003
- Optical frequency metrologyNature, 2002
- Absolute intensities and pressure-broadening coefficients of 2-µm CO_2 absorption features: intracavity laser spectroscopyApplied Optics, 2001
- High-resolution measurements of line intensity, broadening and shift of CO $\mathsf{_2}$ around $\mathsf{2 \mu}$ mThe European Physical Journal D, 1999
- Line strengths of N_2O in the 1120–1440-cm^−1 regionApplied Optics, 1984
- The Levenberg-Marquardt algorithm: Implementation and theoryPublished by Springer Science and Business Media LLC ,1978
- Speed-dependent collisional width and shift parameters in spectral profilesJournal of Quantitative Spectroscopy and Radiative Transfer, 1972
- Problem of Overlapping Lines in the Theory of Pressure BroadeningPhysical Review B, 1958