Direction-reversible asymmetric transmission with tunable chiral metamaterial

Abstract

The asymmetric transmission of electromagnetic waves can be flexibly manipulated by chiral metamaterials hybridized with tunable materials or active components. Here, we propose the concept of a direction-reversible tunable asymmetric transmission effect realized by chiral metamaterials. As the proof-of-concept, twisted metallic meta-sheets consisting of split-ring resonators incorporated with active diodes is designed for linearly polarized operation in the microwave region. The direction of asymmetric transmission depending on the working states of the loaded diodes can be switched by the external bias voltage in real-time. At the same time, the reconfigurable metamaterial also shows ability to control the polarization of the transmitted wave. Both the simulation and experimental results demonstrate that this direction-reversible chiral metamaterial can dynamically adjust the propagating direction of waves, showing potential uses for full-space wave manipulation and versatile modulation devices.