31 January 1994 Photoacoustic/FTIR spectroscopy with a step-scan interferometer
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Proceedings Volume 2089, 9th International Conference on Fourier Transform Spectroscopy; (1994) https://doi.org/10.1117/12.166578
Event: Fourier Transform Spectroscopy: Ninth International Conference, 1993, Calgary, Canada
Limitations of rapid scan PAS measurements can be overcome with a step-scanning interferometer operated in a phase modulation mode. Phase modulation has the desirable effect of modulating all the wavelengths at the same Fourier frequency. This results in an even depth of penetration into a sample across the spectral range observed. Use of a phase demodulator allows for the detection of phase information from the photoacoustic signal rising from the sample. Collection of the in-phase (0 degree phase angle) and in-quadrature (90 degree phase angle) signals allows for the calculation of phase angle information at any chosen angle. This information can be used to produce spectra of a surface and a bulk component in a sample in a single experiment.
© (1994) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Phillip J. Stout and Richard A. Crocombe "Photoacoustic/FTIR spectroscopy with a step-scan interferometer", Proc. SPIE 2089, 9th International Conference on Fourier Transform Spectroscopy, (31 January 1994); doi: 10.1117/12.166578; https://doi.org/10.1117/12.166578

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