Acoustic wave diffraction in metagrating with broken mirror symmetry
Phys. Rev. Applied 26, 044018 – Published 6 October, 2026
DOI: https://doi.org/10.1103/ny67-g8d7
Abstract
Mirror symmetry of transmission is generally considered an inherent property of reciprocal systems. Metagratings, governed by the acoustic diffraction laws in a periodic lattice, have brought vitality to classical wave physics and its manipulation. However, even using the diffraction ability of waves, it remains a challenge to break the mirror symmetry of wave transmission through a single passive metagrating, while simultaneously controlling the wavefront in acoustics. Here, we propose a widely applicable description of acoustic wave diffraction in metagratings by incorporating the coupling between transmitted and reflected waves. Through deliberate design of the transmission and reflection phase gradients, we construct a monolayer passive phase-gradient metagrating that offers advantages of structural integrity and ease of fabrication. This design enables the breaking of mirror symmetry in both acoustic plane wave transmission and reflection within a reciprocal system. We further demonstrate its applicability across a broad range of incident angles, facilitating versatile wavefront manipulation. Our work provides a pathway to advance acoustic communication and isolation, and the underlying principle can be extended to other classical wave systems.
