Chiral Metasurfaces with Maximum Circular Dichroism Enabled by Out-of-Plane Plasmonic System

Chiral metasurfaces with pronounced reflective chiroptical responses have drawn extensive attention as they can offer great opportunities for various chirality-related applications. However, their fascinating potential are restrained by limited chiroptical responses, relatively complex design principle, and fabrication strategy. Herein, a concise and general design principle to develop out-of-plane reflective chiral metasurfaces, empowered with the maximum theoretical circular dichroism (CD), is theoretically proposed and experimentally demonstrated. The designed out-of-plane chiral metasurfaces operating in the terahertz (THz) region are flexibly fabricated via a simple, scalable, low-cost and lithography-free fabrication strategy by integrating a three-dimensional (3D) printing technique. Finally, the methodological stabilities and the strong chiroptical responses of proposed chiral metasurfaces are validated experimentally. From the general design principle, simple fabrication strategy as well as maximum chiroptical responses of proposed reflective chiral metasurfaces, it can be envisaged that these findings may overcome the difficulties in design, optimization, and fabrication for reflective chiral metasurfaces and provide promising potentials for various chirality-related applications in emerging THz technologies, such as chiral sensing, imaging, spectroscopy and polarimetry.

Automated summary

A concise and general design principle is proposed to develop out-of-plane reflective chiral metasurfaces with maximum circular dichroism. The metasurfaces are fabricated using a simple and scalable three-dimensional printing technique. The experimental results validate the stability and strong chiroptical responses of the proposed metasurfaces. These findings have the potential to overcome the difficulties in design, optimization, and fabrication, and provide promising applications in emerging THz technologies.