Abstract
The laser-ultrasonic technique that uses laser to generate and detect ultrasound provides useful utilities in remote non-destructive testing. In present study, aluminum plates with machined slits, which have widths of 0.1 and 0.3 mm and depths varying from 0.2 to 0.6 mm, have been evaluated by surface acoustic wave (SAW). SAWs were generated by a Q-switched YAG laser and monitored by two-wave beam mixing laser interferometer. Two detection modes: reflection and transmission modes were made to detect and characterize flaws. The flaws location can be determined from both detection modes. For transmission mode, detected Rayleigh waveforms depend on flaw length.
