Applied Physics B

, Volume 110, Issue 2, pp 177–185

Multi-harmonic detection in wavelength modulation spectroscopy systems



Two multi-harmonic detection methods for wavelength modulation spectroscopy (WMS) systems are presented and compared. The two possibilities discussed in this paper are: simultaneous curve fitting of multiple harmonic spectra, and reconstruction of the transmission from harmonic coefficients. The optimum number of harmonics is four and 25 harmonics, respectively. Compared with standard single-harmonic curve fitting, the methods give about a factor of 3 better performance than standard second-harmonic curve fitting. Concluding, multi-harmonic detection is better than single-harmonic detection and should be used if the system bandwidth is high enough to allow for proper detection of the higher harmonics.

Copyright information

© Springer-Verlag 2012

Authors and Affiliations

  • A. Hangauer
    • 1
    • 2
  • J. Chen
    • 1
  • R. Strzoda
    • 2
  • M.-C. Amann
    • 1
  1. 1.Walter Schottky InstituteTechnical University of MunichGarchingGermany
  2. 2.Siemens Corporate Research & TechnologiesSiemens AGMunichGermany

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