Parametric phase conjugation of a wide-band acoustic pulse in supercritical mode

Parametric wave phase conjugation of wide-band ultrasonic pulses of 100% relative bandwidth is demonstrated. The giant amplification allowed by the supercritical mode of the magnetoacoustic technique used, leads to a relatively high efficiency of the conjugation process. In addition, the pulse response function of the magnetoacoustic conjugator in supercritical mode is derived by fitting the experimental results with the linear theory of phase conjugation. The latter provides the parameters that define the maximum value of acoustic power in the conjugate wave. The results are of interest for applications in nondestructive evaluation and acoustical imaging.