Reflected wavefront manipulation by acoustic metasurface with anisotropic local resonant units

TL;DR

This paper presents an acoustic metasurface with anisotropic resonant units that can control reflected wavefronts, enabling anomalous reflection and Bessel beam generation through engineered phase profiles.

Contribution

The study introduces a novel anisotropic resonant unit design for acoustic metasurfaces that achieves full 2pi phase control for wavefront manipulation.

Findings

Achieved phase shifts covering 2pi range

Demonstrated anomalous reflection and Bessel beam generation

Potential for advanced acoustic wavefront engineering

Abstract

In this work, we develop the gradient metasurface is constructed of a locally anisotropic resonant structure, comprising a steel cylinder with an elliptical rubber coating embedded in epoxy. The deflective angles of rubber ellipses in the locally anisotropic resonant unit provide a method of controlling the reflected phase. Phase shifts of the reflected wave can cover the 2pi range. With an appropriate design of the phase profiles along the acoustic metasurface, we can achieve anomalous reflection and Bessel beam. The locally anisotropic resonant units have significant potential for engineering and manipulating acoustic wavefronts