title: Frequency dependence of laser ultrasonic SAW phase velocities measurements.
abstract: Advances in the field of laser ultrasonics have opened up new possibilities in applications in many areas. This paper verifies the relationship between phase velocities of different materials, including hard solid and soft solid, and the frequency range of SAW signal. We propose a novel approach that utilizes a low coherence interferometer to detect the laser-induced surface acoustic waves (SAWs). A Nd:YAG focused laser line-source is applied to steel, iron, plastic plates and a 3.5% agar-agar phantom. The generated SAW signals are detected by a time domain low coherence interferometry system. SAW phase velocity dispersion curves were calculated, from which the elasticity of the specimens was evaluated. The relationship between frequency content and phase velocities was analyzed. We show that the experimental results agreed well with those of the theoretical expectations.
authors: School of Engineering, Physics and Mathematics, University of Dundee, Dundee DD1 4HN, Scotland, UK.
authors: Chunhui
authors: C
authors: Li
authors: Shaozhen
authors: S
authors: Song
authors: Guangying
authors: G
authors: Guan
authors: Ruikang K
authors: RK
authors: Wang
authors: Zhihong
authors: Z
authors: Huang
mesh_terms: D000162:Acoustics; D000362:Agar; D055119:Elastic Modulus; D004548:Elasticity; D004867:Equipment Design; D053844:Lasers, Solid-State; D008954:Models, Biological; D015233:Models, Statistical; D055095:Optics and Photonics; D019047:Phantoms, Imaging; D012815:Signal Processing, Computer-Assisted; D013499:Surface Properties; D014465:Ultrasonics / Q000379:methods*
chemical_list: D000362:Agar