title: Surface acoustic wave characterization of optical sol-gel thin layers.
abstract: Controlling the thin film deposition and mechanical properties of materials is a major challenge in several fields of application. We are more particularly interested in the characterization of optical thin layers produced using sol-gel processes to reduce laser-induced damage. The mechanical properties of these coatings must be known to control and maintain optimal performance under various solicitations during their lifetime. It is therefore necessary to have means of characterization adapted to the scale and nature of the deposited materials. In this context, the dispersion of ultrasonic surface waves induced by a micrometric layer was studied on an amorphous substrate (fused silica) coated with a layer of ormosil using a sol-gel process. Our ormosil material is a silica-PDMS mixture with a variable polydimethylsiloxane (PDMS) content. The design and implementation of Surface Acoustic Wave InterDigital Transducers (SAW-IDT) have enabled quasi-monochromatic Rayleigh-type SAW to be generated and the dispersion phenomenon to be studied over a wide frequency range. Young's modulus and Poisson's ratio of coatings were estimated using an inverse method.
authors.affiliation: IEMN-DOAE (UMR CNRS 8520), Institut d'Electronique, de Microélectronique et de Nanotechnologie, Département d'Opto-Acousto-Electronique, Université de Valenciennes, 59313 Valenciennes, France.
authors.forename: Dame
authors.initials: D
authors.lastname: Fall
authors.affiliation: CEA, DAM, Le Ripault, F-37260 Monts, France.
authors.forename: François
authors.initials: F
authors.lastname: Compoint
authors.affiliation: IEMN-DOAE (UMR CNRS 8520), Institut d'Electronique, de Microélectronique et de Nanotechnologie, Département d'Opto-Acousto-Electronique, Université de Valenciennes, 59313 Valenciennes, France.
authors.forename: Marc
authors.initials: M
authors.lastname: Duquennoy
authors.affiliation: CEA, DAM, Le Ripault, F-37260 Monts, France.
authors.forename: Hervé
authors.initials: H
authors.lastname: Piombini
authors.affiliation: IEMN-DOAE (UMR CNRS 8520), Institut d'Electronique, de Microélectronique et de Nanotechnologie, Département d'Opto-Acousto-Electronique, Université de Valenciennes, 59313 Valenciennes, France.
authors.forename: Mohammadi
authors.initials: M
authors.lastname: Ouaftouh
authors.affiliation: IEMN-DOAE (UMR CNRS 8520), Institut d'Electronique, de Microélectronique et de Nanotechnologie, Département d'Opto-Acousto-Electronique, Université de Valenciennes, 59313 Valenciennes, France.
authors.forename: Frédéric
authors.initials: F
authors.lastname: Jenot
authors.affiliation: IEMN-DOAE (UMR CNRS 8520), Institut d'Electronique, de Microélectronique et de Nanotechnologie, Département d'Opto-Acousto-Electronique, Université de Valenciennes, 59313 Valenciennes, France.
authors.forename: Bogdan
authors.initials: B
authors.lastname: Piwakowski
authors.affiliation: CEA, DAM, Le Ripault, F-37260 Monts, France.
authors.forename: Philippe
authors.initials: P
authors.lastname: Belleville
authors.affiliation: CEA, DAM, Le Ripault, F-37260 Monts, France.
authors.forename: Chrystel
authors.initials: C
authors.lastname: Ambard
keywords: IDT transducer; Optical sol-gel layers; SAW sensor; Surface acoustic wave; Ultrasonic NDT