Acoustic geometric-phase meta-array

Metasurfaces based on geometric phase acquired from the conversion of the optical spin states provide a robust control over the wavefront of light, and have been widely employed for construction of various types of functional metasurface devices. However, this powerful approach cannot be readily transferred to the manipulation of acoustic waves because acoustic waves do not possess the spin degree of freedom. Here, we propose the concept of acoustic geometric-phase meta-array by leveraging the conversion of orbital angular momentum of acoustic waves, where well-defined geometric-phases can be attained through versatile topological charge conversion processes. This work extends the concept of geometric-phase metasurface from optics to acoustics, and provides a new route for acoustic wave control.

Automated summary

This work introduces the concept of an acoustic geometric-phase meta-array, which leverages the conversion of orbital angular momentum of acoustic waves to achieve well-defined geometric phases, extending the concept of geometric-phase metasurfaces from optics to acoustics and offering a new route for controlling acoustic waves.