Characterization of the photo-emf response for laser-based ultrasonic sensing under simulated industrial conditions

摘要

There is a need in myriad manufacturing environments to nondestructively evaluate components and to control prcesses in real-time. Laser-based ultrasound [1,2], LBU, has the potential to be a robust, reconfigurable, noncontact diagnostic for many industrial applications. A simple and inexpensive semiconductor sensor based on the nonsteady-state photo-induced-electromoitve force (photo-emf) effect [3,4], has been demonstrated [5] to be functional under a variety of manufacturing conditions and in probing varous materials, including metals, semiconductors, and organics. This device has the potential to remotely sense ultrasound via speckle motion or coherent detection over a reasonable field-of-view, with good bandwidth and detection sensitivity.