Laser Ultrasonic Inspection Based on In-Plane Detection and Shear Wave Generation

We present a compact Laser Ultrasonic (LU) receiver based on two-wave mixing in photorefractive materials, for simultaneous measurement of the out-of-plane and of the in-plane displacements (2component). By taking advantage of recent developments in electronic processing, we achieved a compact optical architecture using only a single collecting aperture and a single laser probe beam. Complementary to the 2-component detection, we will also present an improved LU source for noncontact generation of normal-incidence shear waves. Results from characterization of the receiver and the generation are shown, and application to defect detection is demonstrated.