TIME-FREQUENCY-ENERGY ANALYSIS OF ULTRASOUND WAVES GENERATED AND DETECTED BY LASER - APPLICATION TO QUALITY-CONTROL

Ultrasounds are generally used in non-destructive testing (NDT) with s ensors working with a narrow bandwith. The optical sensors generate an d detect acoustical waves without contact and arrows measurements in a wide band of frequencies. From this fact, the information contained i n the signal captured is complete and give informations (celerity calc ulated by the time arrival of acoustical waves, attenuation and defect presence). The time-frequency-energy analysis is efficient for the ac oustical waves comportment analysis in samples.