title: Effect of refracted light distribution on the photoelastic generation of zero-group velocity Lamb modes in optically low-absorbing plates.
abstract: Zero-group velocity (ZGV) Lamb modes are associated with sharp local acoustic resonances and allow, among other features, local measurement of Poisson's ratio. While the thermoelastic generation of Lamb waves in metal plates has been widely studied, the case of materials of low-optical absorption remains unexplored. In materials such as glasses, the generation of bulk elastic waves has been demonstrated to be sensitive to the refracted light distribution. In this paper, a detailed analysis of the effect of light refraction on the laser-based generation of ZGV Lamb modes is presented. Experiments are performed on a bare glass plate without the need for an additional layer for light absorption or reflection. Using an appropriate tilted volume source, it is shown that the laser-ultrasonic technique allows non-contact measurement of the Poisson's ratio.
authors.affiliation: ESPCI ParisTech, CNRS, PSL Research University, Institut Langevin, 1 Rue Jussieu, F-75005, Paris, France.
authors.forename: Samuel
authors.initials: S
authors.lastname: Raetz
authors.affiliation: ESPCI ParisTech, CNRS, PSL Research University, Institut Langevin, 1 Rue Jussieu, F-75005, Paris, France.
authors.forename: Jérôme
authors.initials: J
authors.lastname: Laurent
authors.affiliation: University of Bordeaux, CNRS, Unité Mixte de Recherche 5295, I2M, F-33400, Talence, France.
authors.forename: Thomas
authors.initials: T
authors.lastname: Dehoux
authors.affiliation: ESPCI ParisTech, CNRS, PSL Research University, Institut Langevin, 1 Rue Jussieu, F-75005, Paris, France.
authors.forename: Daniel
authors.initials: D
authors.lastname: Royer
authors.affiliation: University of Bordeaux, CNRS, Unité Mixte de Recherche 5295, I2M, F-33400, Talence, France.
authors.forename: Bertrand
authors.initials: B
authors.lastname: Audoin
authors.affiliation: ESPCI ParisTech, CNRS, PSL Research University, Institut Langevin, 1 Rue Jussieu, F-75005, Paris, France.
authors.forename: Claire
authors.initials: C
authors.lastname: Prada