title: Determination of thermoelastic material properties by differential heterodyne detection of impulsive stimulated thermal scattering.
abstract: The underlying working principle of detecting impulsive stimulated scattering signals in a differential configuration of heterodyne diffraction detection is unraveled by involving optical scattering theory. The feasibility of the method for the thermoelastic characterization of coating-substrate systems is demonstrated on the basis of simulated data containing typical levels of noise. Besides the classical analysis of the photoacoustic part of the signals, which involves fitting surface acoustic wave dispersion curves, the photothermal part of the signals is analyzed by introducing thermal wave dispersion curves to represent and interpret their grating wavelength dependence. The intrinsic possibilities and limitations of both inverse problems are quantified by making use of least and most squares analysis.
authors.affiliation: Laboratory of Acoustics and Thermal Physics, Department of Physics and Astronomy, KU Leuven, Celestijnenlaan 200D, B-3001 Heverlee, Belgium.
authors.forename: B
authors.initials: B
authors.lastname: Verstraeten
authors.affiliation: Laboratory of Acoustics and Thermal Physics, Department of Physics and Astronomy, KU Leuven, Celestijnenlaan 200D, B-3001 Heverlee, Belgium.
authors.forename: J
authors.initials: J
authors.lastname: Sermeus
authors.affiliation: Laboratory of Acoustics and Thermal Physics, Department of Physics and Astronomy, KU Leuven, Celestijnenlaan 200D, B-3001 Heverlee, Belgium.
authors.forename: R
authors.initials: R
authors.lastname: Salenbien
authors.affiliation: KU Leuven, Campus Brussels, Warmoesberg 26, B-1000 Brussels, Belgium.
authors.forename: J
authors.initials: J
authors.lastname: Fivez
authors.affiliation: Institute of Radio Engineering and Electronics of the Russian Academy of Sciences, Vvedensky sq., 1, Fryazino, Moscow Region, Russia.
authors.forename: G
authors.initials: G
authors.lastname: Shkerdin
authors.affiliation: Laboratory of Acoustics and Thermal Physics, Department of Physics and Astronomy, KU Leuven, Celestijnenlaan 200D, B-3001 Heverlee, Belgium.
authors.forename: C
authors.initials: C
authors.lastname: Glorieux
keywords: Coating-substrate samples; Differential heterodyne detection; Impulsive stimulated scattering; Optical scattering theory; Thermal wave dispersion; Thermoelastic material property characterization