Two-dimensional terahertz beam manipulations based on liquid-crystal-assisted programmable metasurface

In this paper, an approach is proposed toward two-dimensional (2D) beam tailoring in the terahertz band based on programmable metasurface loaded with liquid crystals. Specifically, a 1-bit reflective metasurface element is designed with switchable phase responses, and subsequently, an individually controllable metasurface array in 2D fashion is achieved by pixelating the metallic reflection back plate. As typical examples, programmable metasurfaces operating around 94 and 220 GHz are developed, respectively, and both simulation and experimental results confirm the powerful abilities of the metasurfaces in 2D wide-angle beam manipulations. In addition, the proposed method has advantages of wide frequency range, low cost, and high reliability, implying significant application prospects in terahertz reconfigurable intelligent surfaces and holographic imaging.