Abstract

A technique of using second derivative spectra has been developed by which accurate infrared line widths and shapes may be measured using a single-beam tunable diode laser spectrometer both for a flat background and in the presence of a sloping background. It is shown that there exist easily measured parameters of the second derivative line profile which are independent of a small linearly sloping background. A procedure was developed which uses sets of precomputed model line profiles to allow an estimate of the true linewidth of a line to be derived from the second derivative spectrum. The accuracy of this technique is limited by the accuracy with which the second derivative line profile can be measured.

Calibration of diode-laser second-derivative modulation spectrometry with a reference cell

Claus Weitkamp
Appl. Opt. 23(1) 83-86 (1984)

Background signals in wavelength-modulation spectrometry with frequency-doubled diode-laser light. I. Theory

Pawel Kluczynski, Åsa M. Lindberg, and Ove Axner
Appl. Opt. 40(6) 783-793 (2001)

Determining tunable diode laser spectrometer performance through measurement of N₂O line intensities and widths at 7.8 μm

Da-Wun Chen, Edward R. Niple, and Sherman K. Poultney
Appl. Opt. 21(16) 2906-2911 (1982)

Measurement of molecular concentrations and line parameters using line-locked second harmonic spectroscopy with an AlGaAs diode laser

Neil Goldstein, Steven Adler-Golden, Jamine Lee, and Fritz Bien
Appl. Opt. 31(18) 3409-3415 (1992)

Tunable diode laser measurements of formaldehyde foreign-gas broadening parameters and line strengths in the 9–11 μm region

Shachar Nadler, Stephen J. Daunt, and Dennis C. Reuter
Appl. Opt. 26(9) 1641-1646 (1987)