Compression and decompression of ultrasonic echoes by means of parametric wave phase conjugation

The properties of magnetoacoustic Parametric Wave Phase Conjugation (WPC) in presence of multiscatterers and conditions of double pulse pumping are studied for the first time. The analyse of the temporal behaviour of the time reversed echoes from complex scatterers in several iterations of WPC process shows that specific phenomena of compression and decompression of ultrasonic scattered signals can arise. The results are of interest for non destructive testing applications.