AIR-COUPLED PIEZOELECTRIC DETECTION OF LASER-GENERATED ULTRASOUND

Advances in the design of piezoelectric detectors will be described, which have increased their sensitivity for operation in air. This makes them suitable for the non-contact detection of ultrasonic waves in a solid, by sensing waves transmitted through a solid-air interface. It is shown that the additional use of a pulsed laser for ultrasonic generation leads to a completely non-contact ultrasonic system, of interest to workers in non-destructive evaluation.