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

Parametric wave phase conjugation of wide-band ultrasonic pulses of 100% re lative bandwidth is demonstrated. The giant amplification allowed by the su percritical mode of the magnetoacoustic technique used, leads to a relative ly high efficiency of the conjugation process. In addition, the pulse respo nse function of the magnetoacoustic conjugator in supercritical mode is der ived by fitting the experimental results with the linear theory of phase co njugation. The latter provides the parameters that define the maximum value of acoustic power in the conjugate wave. The results are of interest for a pplications in nondestructive evaluation and acoustical imaging. (C) 2000 A merican Institute of Physics. [S0003-6951(00)00203-5].