Origin of diffuse scattering appearing in iron-doped Ti-Ni shape memory alloys

Light diffraction in acoustic fields created by wedge-shaped and parabolic piezoelectric transducers is theoretically investigated. It is shown that the acoustic fields have a complicated amplitude-phase structure changing with the acoustic frequency. Principal characteristics of acousto-optic interaction are examined. It is demonstrated that the diffraction efficiency in the Bragg regime can approach 100% in spite of a noticeable phase mismatch.