Acoustic analog of the magnetooptical Kerr effect

Upon reflection of a transverse linearly polarized ultrasonic wave from the interface between the fused quartz and single-crystal yttrium iron garnet, polarization changes dependent on the applied magnetic field H, such as co nversion to elliptic polarization and rotation of the polarization plane, w ere revealed. The experiments were conducted at a temperature of 295 K in f ields above the magnetic saturation with a held parallel to the hard axis ( H parallel to [001]). The orientation of the magnetic field and of the pola rization of the incident wave with respect to the interface corresponded to the acoustic analog of the polar magnetooptical Kerr effect. Dependences o n the applied magnetic field of parameters such as the angle of rotation of the polarization axis and the ellipticity of the reflected ultrasonic wave were calculated on the basis of the theory of elastic: and spin waves. The origin of differences between the theoretical and experimental curves is d iscussed.