Acoustic superfocusing by solid phononic crystals

作者:Zhou Xiaoming; Assouar M Badreddine*; Oudich Mourad
来源:Applied Physics Letters, 2014, 105(23): 233506.
DOI:10.1063/1.4904262

摘要

We propose a solid phononic crystal lens capable of acoustic superfocusing beyond the diffraction limit. The unit cell of the crystal is formed by four rigid cylinders in a hosting material with a cavity arranged in the center. Theoretical studies reveal that the solid lens produces both negative refraction to focus propagating waves and surface states to amplify evanescent waves. Numerical analyses of the superfocusing effect of the considered solid phononic lens are presented with a separated source excitation to the lens. In this case, acoustic superfocusing beyond the diffraction limit is evidenced. Compared to the fluid phononic lenses, the solid lens is more suitable for ultrasonic imaging applications.