| 摘要 |
<p>In a method for ultrasonic testing of objects, ultrasound is generated inside or at the surface of the object. The surface of the object is illuminated with a beam from a long-pulse laser oscillator, typically in the range 1 νs to a few 100 νs, that is substantially free of intensity fluctuations. The light from the incident beam that is scattered or reflected by the surface of the object is collected and demodulated to obtain a signal representative of the ultrasonic motion. The method allows for the use of a compact and efficient arrangement.</p> |
