Synthetic aperture focusing technique data processing applied to laser-ultrasonics

Laser-ultrasonics is an emerging nondestructive technique using lasers for the generation and detection of ultrasound which presents numerous advantages for industrial inspection. In this paper, the problem of the detection by laser-ultrasonics of small defects within a material is addressed. Experimental results obtained with laser-ultrasonics are reported and processed using the Synthetic Aperture Focusing Technique (SAFT), yielding improved flaw detectability and spatial resolution. Experiments have been performed on an aluminum sample with a contoured back surface and two flat-bottom holes. Practical interest of coupling SAFT to laser-ultrasonics is also discussed.