Sliding-tunable terahertz beam meta-deflector based on a 3D-printed bilayer

To cope with the rapid preparation and tunable function of terahertz (THz) devices, a kind of THz beam meta-deflector (BMD) based on a bilayer metasurface doublet is proposed to implement tunable beam deflection with additional functions. By superimposing functional phases on one of the layers and sliding the other layer, the BMDs can achieve continuously beam deflection with beam splitting or beam focusing. It is possible to quickly switch between different functions by replacing the functional phase. As a demonstration, two devices are designed and fabricated by 3D printing, including a splitting BMD (s-BMD) and a focusing BMD (f-BMD). The experimental results show that the designed metasurfaces can achieve a deflection of ±26.96° while achieving a splitting angle of 38.94°-44.11° for the s-BMD and a focus deflection of ±30.76° for the f-BMD. The BMD is expected to be applied as a multifunctional and tunable device in THz communication and imaging.