Controllably asymmetric beam splitting via gap-induced diffraction channel transition in dual-layer binary metagratings

TL;DR

This paper presents a dual-layer binary metagrating that enables controllable asymmetric and symmetric beam splitting through gap-induced diffraction, with simple design and tunable properties for wave manipulation applications.

Contribution

The work introduces a novel dual-layer binary metagrating design that achieves tunable asymmetric transmission by controlling the air gap, simplifying the design process compared to previous acoustic metasurfaces.

Findings

High-efficiency beam splitting achieved

Switchable between asymmetric and symmetric transmission

Operates over a broad frequency and incident range

Abstract

In this work, we designed and studied a feasible dual-layer binary metagrating, which can realize controllable asymmetric transmission and beam splitting with nearly perfect performance. Owing to ingenious geometry configuration, only one meta-atom is required to design for the metagrating system. By simply controlling air gap between dual-layer metagratings, high-efficiency beam splitting can be well switched from asymmetric transmission to symmetric transmission. The working principle lies on gap-induced diffraction channel transition for incident waves from opposite directions. The asymmetric/symmetric transmission can work in a certain frequency band and a wide incident range.Compared with previous methods using acoustic metasurfaces, our approach has the advantages of simple design and tunable property and shows promise for applications in wavefront manipulation,noise control and acoustic diode.