Open AccessWavelength modulation spectroscopy for recovering absolute absorbance
Author(s) -
Yong Du,
Zhimin Peng,
Yao Ding
Publication year - 2018
Publication title -
optics express
Language(s) - Uncategorized
Resource type - Journals
SCImago Journal Rank - 1.394
H-Index - 271
ISSN - 1094-4087
DOI - 10.1364/oe.26.009263
Subject(s) - absorbance , optics , materials science , spectroscopy , calibration , wavelength , modulation (music) , tunable diode laser absorption spectroscopy , sensitivity (control systems) , absorption spectroscopy , laser , absorption (acoustics) , noise (video) , residual , tunable laser , physics , computer science , electronic engineering , algorithm , quantum mechanics , artificial intelligence , acoustics , image (mathematics) , engineering
A highly sensitive, calibration-free method, wavelength modulation - direct absorption spectroscopy (WM-DAS), is proposed by extracting the characteristic frequencies of modulated laser intensity. This method combines the advantages of measuring absolute absorbance profile from calibration-free DAS with the enhanced noise rejection and high sensitivity of WMS. The preliminary validation experiment of H 2 O transitions shows that the WM-DAS method improves the accuracy of the absorbance profile measurement with a best-fit standard residual of 4.9 × 10 -5 . This new method might inspire new approaches to high-precision measurement of spectral line parameters and gas information with weak absorptions or industrial applications.