Reconfigurable conversions of reflection, transmission, and polarization states using active metasurface

Metasurfaces have shown powerful abilities in controlling the reflections, transmissions, and polarizations of lights or electromagnetic (EM) waves, independently. Here, we propose a single active metasurface to achieve reconfigurable EM-wave transmissions and reflections, and simultaneously cross-linearized polarization conversions. The active metasurface contains two metallic layers and a middle dielectric layer. The top metallic layer is composed of periodic metallic short wires, which are designed to convert the polarization. PIN diodes are embedded on the bottom metallic layer to switch the polarization and transmission-reflection conversions. When the PIN diode is turned off, the linearly polarized incident waves are transmitted through the metasurface with almost perfect polarization rotation to its orthogonal direction; when the PIN diode is turned on, however, the metasurface will reflect the incident waves with the same linear polarization. Both numerical simulations and experimental results show good reconfigurable performance of the proposed active metasurface.