Metasurfaces have attracted broad interest thanks to their unprecedented capacity for electromagnetic wavefront manipulation. The compact, ultrathin and multifunctional metasurface calls for novel design principles. Here, we propose and experimentally demonstrate a non-interleaved and non-segmented bidirectional Janus metasurface that encodes multiple functionalities in full-space scattering channels with different propagation directions and polarization in the microwave region. Specifically, by rotating and adjusting the elementary double-arrow-shaped structure within the same meta-atom, the independent phase control can be achieved in both cross-polarized transmission and co-polarized reflection components under oppositely directed incident waves. Our metasurface with broken mirror symmetry can fully exploit four independent information channels under opposite propagation directions. A series of proof-of-concept is constructed to validity of our methodology, and the simulations and experimental results further show that the proposed non-interleaved bidirectional metasurface can provide an attractive platform for various applications, ranging from structured light conversion, optical imaging, multifunctional optical information processing and others.

中文翻译：

---

具有全空间散射通道的非交错双向 Janus 超曲面

超表面因其前所未有的电磁波前操纵能力而引起了广泛的兴趣。紧凑、超薄和多功能的超表面需要新颖的设计原则。在这里，我们提出并通过实验证明了一种非交错和非分段的双向 Janus 超表面，该超表面在全空间散射通道中编码多种功能，在微波区域具有不同的传播方向和极化。具体而言，通过旋转和调整同一元原子内的基本双箭头形结构，可以在相反方向的入射波下实现交叉偏振透射和共偏振反射分量的独立相位控制。我们的具有破坏镜像对称性的超表面可以在相反的传播方向下充分利用四个独立的信息通道。为验证我们方法的有效性，构建了一系列概念验证，模拟和实验结果进一步表明，所提出的非交错双向超表面可以为各种应用提供有吸引力的平台，从结构光转换、光学成像、多功能光学信息处理等。