Laser ultrasonic detecting device and laser ultrasonic detecting method

摘要

PURPOSE: A laser ultrasonic detecting device and a laser ultrasonic detecting method are provided to improve ultrasonic wave measurement sensitivity by maintaining measurement performance even in a vibrated place. CONSTITUTION: A laser ultrasonic detecting device comprises a laser beam source(11) for ultrasonic generation, a laser beam source for ultrasonic detection, a Fabry-Perot interferometer(13), a resonant length controller(50), and a signal processing part(60). The laser beam source for the ultrasonic generation emits pulse laser beam on a test material and generates ultrasonic wave. The laser beam source for the ultrasonic detection emits laser beam for ultrasonic detection on the test material and detects ultrasonic wave. The Fabry-Perot interferometer emits the laser beam for ultrasonic detection and passes a part of the laser beam for the ultrasonic wave. The resonant length controller of the Fabry-Perot interferometer is periodically changed.