2007 Volume 1 Issue 9 Pages 1128-1135
The possibility of detecting laser-generated ultrasound using slight temperature increases with piezoelectric sensors was investigated. The ultrasound noise generated by nanosecond laser irradiation with a theoretically 1 K temperature-rise was detected clearly by the piezoelectric AE sensors using a built-in head amplifier. The amplitude of the first arrival peaks obtained using the side and front sensors decreased monotonically with the source-sensor separation. The amplitude of ultrasound generated by femtosecond laser irradiation was greater than that by nanosecond laser irradiation with same pulse energy, but no great difference existed in the frequency spectrum of the ultrasonic waveforms.
