A New Line-Shape Asymmetry Model for Wavelength Modulation Spectroscopy in Gaseous Flows

0500338 - ÚFCH JH 2019 RIV SK eng J - Journal Article
Nevrlý, V. - Klečka, V. - Vašinek, M. - Válek, V. - Suchánek, Jan - Dostál, Michal - Hric, B. - Bitala, P. - Zelinger, Zdeněk
A New Line-Shape Asymmetry Model for Wavelength Modulation Spectroscopy in Gaseous Flows.
Measurement Science Review. Roč. 18, č. 4 (2018), s. 158-161. ISSN 1335-8871. E-ISSN 1335-8871
R&D Projects: GA MŠMT(CZ) LTC17071; GA ČR(CZ) GA17-05167s
Grant - others:European Cooperation in Science & Technology(XE) CM1404
Institutional support: RVO:61388955
Keywords : laser spectrometer * calibration * frequency * gas sensing * spectroscopy * modulation * model * line-shape asymmetry
OECD category: Physical chemistry
Impact factor: 1.122, year: 2018

This communication reports technical notes on the development and application of an automated line-shape fitting procedure for wavelength modulation spectroscopy (WMS). Near-infrared transitions of carbon dioxide (CO2) around 1573 nm were measured in vertical cold (non-reacting) flow of CO2 at atmospheric pressure using WMS with demodulation at second harmonic frequency. Semi-empirical model based on the set of so-called Gabor functions was developed and parameters of Lorentzian line-shape profile and its asymmetry resulting from simultaneous frequency and amplitude response of the current-modulated semiconductor laser were determined. Nonlinear least-square fitting procedure employing differential evolution algorithm was successfully utilized for performing this task. Line-shape fitting procedure enabling efficient signal de-noising and background subtraction of wavelength modulation spectra was implemented into an open-source code.
Permanent Link: http://hdl.handle.net/11104/0292430