About Diffraction Phenomena Accompanying Nonlinear Transformations in Focused Acoustic Fields

Abstract

In this paper, the diffraction effects accompanied by the nonlinear transformations in inhomogeneous acoustic fields are studied experimentally. The case where a converging spherical wave front propagates in a homogeneous nonlinear medium, the acoustic field is detected in the focus, and the detected signal is received in the region of the initial wave‐front aperture is considered. A spherical piezoelectric concentrator is used as the focusing device in our experiments. The “nonlinear scattering” signals, also at large angles and in the direction of the initial aperture of the radiator, were registered using the specially constructed experimental setup in which the pulsed regime of concentrator operation in water was realized. The dependences of the amplitude and temporal profile of the signal detected in the focal area on the direction of scattering and the distance from the focus to the reception point are studied.