Focusing Acoustic Beams with a Ball-Shaped Lens beyond the Diffraction Limit

被引：48

作者：

Lopes, J. H. ^{[1
]}

Andrade, M. A. B. ^{[2
]}

Leao-Neto, J. P. ^{[3
]}

Adamowski, J. C. ^{[4
]}

Minin, I. V. ^{[5
]}

Silva, G. T. ^{[3
]}

机构：

[1] Univ Fed Alagoas, Nucleo Ciencias Exatas, Grp Fis Mat Condensada, BR-57309005 Arapiraca, Alagoas, Brazil

[2] Univ Sao Paulo, Inst Phys, BR-05314970 Sao Paulo, SP, Brazil

[3] Univ Fed Alagoas, Inst Fis, Phys Acoust Grp, BR-57072970 Maceio, Alagoas, Brazil

[4] Univ Sao Paulo, Dept Mechatron & Mech Syst Engn, BR-05508030 Sao Paulo, SP, Brazil

[5] Siberian State Univ Geosyst & Technol, Novosibirsk 630108, Russia

来源：

PHYSICAL REVIEW APPLIED | 2017年 / 8卷 / 02期

关键词：

RADIATION FORCE; SCATTERING; PARTICLE; TORQUE;

D O I：

10.1103/PhysRevApplied.8.024013

中图分类号：

O59 [应用物理学];

学科分类号：

摘要：

We report on measurements of a subwavelength focusing of an ultrasound beam by a polymer ball-shaped lens (Rexolite) immersed in water at room temperature. The beam arises in the near field of the ball-lens shadow side. Considering a 8.2 lambda-diameter ball lens, with lambda being the wavelength, we find a superfocused beam with 14.4-dB-intensity gain, a full width and a full length at half maximum of lambda/2 and 2.2 lambda, respectively, and sidelobes under -10 dB. The observed phenomenon is in excellent agreement with the theoretical and computational predictions based on the partial-wave expansion and finite-element methods. Our results may foster the design of simple lens elements for super-resolution acoustic microscopy and ultrasound imaging.

引用

页数：7