Non-Interleaved Janus Metasurfaces Enabling Bidirectional Dual-Band Dual-Polarization Wavefront Engineering

Janus metasurfaces have emerged as transformative platforms for controlling electromagnetic wave propagation and exhibit unprecedented capabilities in asymmetric functionalities. Such designed interfaces enable directional wavefront manipulation, opening up new possibilities for bidirectional optical communication systems. However, introducing polarization multiplexing into bidirectional transmission while manipulating bidirectional spatial incident waves using a single non-Interleaved metasurface remains challenging. Here, a non-interleaved bidirectional Janus metasurface is proposed, which achieves five-channel wavefront manipulation by simultaneously transmitting through tri-polarization channels in the forward direction and reflecting through dual-polarization channels in the backward direction at different frequencies. In addition, separate phase distributions are encoded into distinct polarization channels with nearly zero mutual interference among the five channels. Benefiting from its multifunctional capabilities, the proposed Janus metasurface provides strong technical support for realizing high-efficiency and secure data transmission in next-generation wide-area wireless communication systems.