Journal Article

A holey-structured metamaterial for acoustic deep-subwavelength imaging

Zhu, J., Yin, X., Martin-Moreno, L., Christensen, J., Jung, J., Zhang, X., Garcia-Vidal, F. J., Fok, L.

2011

Overview

A three-dimensional periodic structure focuses acoustic waves to a spot size that is one fiftieth of the wavelength—beating the classical diffraction limit by a long way. The device could lead to improved resolution for ultrasound imaging. For classical waves such as light or sound, diffraction sets a natural limit on how finely the details of an object can be recorded on its image. Recently, various optical superlenses based on the metamaterials concept have shown the possibility of overcoming the diffraction limit 1 , 2 , 3 , 4 , 5 , 6 , 7 . Similar two-dimensional (2D) acoustic hyperlens designs have also been explored 8 , 9 , 10 . Here we demonstrate a 3D holey-structured metamaterial that achieves acoustic imaging down to a feature size of λ /50. The evanescent field components of a subwavelength object are efficiently transmitted through the structure as a result of their strong coupling with Fabry–Pérot resonances inside the holey plate. This capability of acoustic imaging at a very deep-subwavelength scale may open the door for a broad range of applications, including medical ultrasonography, underwater sonar and ultrasonic non-destructive evaluation.

• Publisher: Nature Publishing Group UK,Nature Publishing Group
• Subject: Acoustic imaging / Acoustics / Atomic / Classical and Continuum Physics / Complex Systems / Condensed Matter Physics / Diffraction / letter / Mathematical and Computational Physics / Medical / Metamaterials / Molecular / Optical and Plasma Physics / Physics / Physics and Astronomy / Theoretical / Three dimensional / Two dimensional / Ultrasonic testing / Wave power