Janus Vectorial Complex‐Amplitude Holography Based on Terahertz Magnetized Photonic Weyl Semimetal Metasurface

ABSTRACT Janus metasurfaces endow the channels with physical‐layer asymmetry, a key property of encryption and unidirectional systems. However, the complexity arising from such asymmetry hinders Janus metasurfaces from incorporating more dynamic channels and manipulation dimensions, further restricting their information processing capability. Herein, we demonstrate a Janus vectorial complex‐amplitude holography via magnetized photonic Weyl semimetal metasurface, which enables dynamic modulation and high‐dimensional optical manipulation covering full Poincare Sphere. Based on the robust polarization dichroism modulation of Weyl semimetal, four dynamic asymmetry channels with complex‐amplitude images from the vectorial hologram are reconstructed. The experiment demonstrates its maximum isolation of 31.72 dB and maximum modulation depth of 97.4% at the functional frequency of 0.55THz. Finally, we employ physical‐layer asymmetry in Janus metasurfaces to asymmetric secure communication, which is expected to avoid the attack algorithm. This metasurface extends the dimensions and dynamic states of Janus imaging and paves the way for next‐generation terahertz communication networks with high security and high capacity.