Low-cost, compact, robust laser-based ultrasound sensors using photo-EMF detection
- Hughes Research Labs., Malibu, CA (United States)
- Melles Griot, Irvine, CA (United States)
There is a great need in the manufacturing, aerospace, commercial, energy, automotive, microelectronics and DoD communities for diagnostic systems that can improve the efficiency, yield and performance of various materials processes--while reducing cost, labor, scrap, and machine downtime. Laser-based ultrasound (LBU) represents a noncontact, reconfigurable, high-bandwidth ultrasonic inspection and process control technology. LBU enables remote ultrasonic sensing by replacing conventional PZT transducers, squirters, and immersion systems with laser beams. One laser beam generates the ultrasound in an opaque workpiece, while a second laser beam probes the sample to sense minute surface displacements, induced by the ultrasound or via other acoustic emission mechanisms. LBU systems have yet to be fielded commercially, owing primarily to the cost, size, and complexity of the system components. The authors have developed a low-cost, compact sensor which can potentially enable LBU systems to become a reality. The sensor employs a semiconductor crystal (GaAs) using a mechanism called nonsteady-state photo-induced emf. When combined with a laser diode as an optical source, the result is a very compact, low-cost robust sensor, which can function under in-factory conditions, including inspection of rough-cut workpieces which undergo rapid platform motion, such as high-speed, scanning laser welders. Experimental results will be discussed, including the potential for optical fiber delivery.
- OSTI ID:
- 550035
- Report Number(s):
- CONF-9610109-; ISBN 1-57117-053-7; TRN: IM9753%%110
- Resource Relation:
- Conference: 1996 Fall conference and quality testing show. NDT - new horizons on the Pacific, Seattle, WA (United States), 14-18 Oct 1996; Other Information: PBD: 1996; Related Information: Is Part Of ASNT 1996 fall conference and quality testing show: Paper summaries; PB: 246 p.
- Country of Publication:
- United States
- Language:
- English
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