Российский фонд
фундаментальных
исследований

Физический факультет
МГУ им. М.В.Ломоносова
 

12.07 Обращение фронта и времени, адаптивные системы

 

Liu S., Li M., Zhao R. «The Sound Source Location Based on Phase Conjugation and Acoustic Superlens» Acoustical Physics, 70, № 1, с. 58-67 (2024)

In order to break through the diffraction limit of traditional sound sources, an idea of far-field super-resolution imaging based on acoustic superlens is proposed, that is, acoustic super-lens is used to transmit near-field sound field information to the far-field, and far-field super-resolution imaging is realized by combining phase conjugate algorithm. In this paper, the sound source localization effect of the two-dimensional honeycomb acoustic superlens of water/mercury material is systematically studied, and the sub-wavelength imaging with a resolution of 0.22λ is obtained by simulating the point sound source imaging through numerical simulation, and the imaging principle of the refractive index n=–1 configuration is explained by combining the imaging principle of flat lens imaging and the law of refraction. A multi-lens was designed for far-field localization of point sound sources, and sub-wavelength imaging with a resolution of 0.19λ was obtained.

Acoustical Physics, 70, № 1, с. 58-67 (2024) | Рубрики: 06.15 12.07

 

Tsysar S.A., Rosnitskiy P.B., Asfandiyarov S.A., Petrosyan S.A., Khokhlova V.A., Sapozhnikov O.A. «Phase Correction of the Channels of a Fully Populated Randomized Multielement Therapeutic Array Using the Acoustic Holography Method» Acoustical Physics, 70, № 1, с. 82-89 (2024)

The acoustic holography method was used to characterize a therapeutic focused fully populated 256-element ultrasonic transducer array. Elements of the array with the shape of equal area polygons are densely arranged in an irregular pattern on a spherically concave surface with a radius of curvature of 150 mm and a diameter of 200 mm. The array has a central frequency of 1.2 MHz and is designed to operate in water. The performance of individual array elements was studied based on the holographically reconstructed normal velocity distribution over the array surface. It was shown that with the same electrical signals applied to the elements, their acoustic responses had a phase deviation relative to the nominal values, which can be caused either by the asphericity of the array surface, or by the introduction of additional phase delays by the electrical matching network. To compensate for the detected parasitic phase shifts of the elements and restore the effective sphericity of the radiating surface, the Verasonics V-1 control system was used. The hologram measured after making the correction, as well as the shape of the focal region and acoustic pressure magnitude at the focus, separately measured by a hydrophone, showed that the proposed method reconstructed the nominal operating parameters of the array with high accuracy.

Acoustical Physics, 70, № 1, с. 82-89 (2024) | Рубрики: 12.01 12.06 12.07