Document Type

Article

Publication Date

4-2002

Journal or Book Title

Applied Spectroscopy

Volume

56

Issue

4

First Page

409

Last Page

418

DOI

10.1366/0003702021954926

Abstract

Depth profiling using photoacoustic spectra taken at multiple scanning speeds or modulation frequencies is normally impaired by the increase in spectral saturation that occurs with decreasing speed or frequency. Photothermal depth profiling in general is also impeded by the ill conditioned nature of the mathematical problem of determining a depth profile from photothermal data. This paper describes a method for reducing the saturation level in low-speed or low-frequency spectra to the level at high speed or frequency so that all spectra have the same saturation. The conversion method requires only magnitude spectra, so it is applicable to both conventional and phase-modulation photoacoustic spectra. This paper also demonstrates a method for quantitative depth profiling with these converted spectra that makes use of prior knowledge about the type of profile existing in a sample to reduce the instabilities associated with the mathematically ill conditioned task.

Comments

This paper was published in Applied Spectroscopy 56 (2002): 409 and is made available as an electronic reprint with the permission of OSA. The paper can be found at the following URL on the OSA website: doi:10.1366/0003702021954926.

Rights

Systematic or multiple reproduction or distribution to multiple locations via electronic or other means is prohibited and is subject to penalties under law.

Copyright Owner

Society for Applied Spectroscopy

Language

en

File Format

application/pdf

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