Specifications of an Ultrasonic Receiver Based on Two-Wave Mixing in Photorefractive Gallium Arsenide Implemented in a Laser-Ultrasonic System

Optical techniques for ultrasonic measurements present several advantages over conventional piezoelectric methods. First, they are remote sensing techniques and can be, for example, used for the inspection of materials at elevated temperature or products moving on a production line. Secondly, surfaces of complex shape can be easily probed since these techniques work with scattered light. For specific applications, these advantages compensate the usually lower sensitivity of optical techniques.