Non-Interleaved Janus Metasurface for Independent Wavefront Engineering of Arbitrary Polarizations

Metasurfaces have been extensively explored through various multiplexing strategies as powerful platforms for electromagnetic wave manipulation. However, direction multiplexing remains relatively underexplored, suffering from low efficiency caused by interleaved atoms and limited polarization versatility. Here, a novel concept of non-interleaved Janus meta-devices is proposed for an operation in the microwave regime, which enables high-efficiency, asymmetric wavefront control of arbitrarily polarized waves. For demonstration and potential applications, we design two proof-of-concept meta-devices by simultaneously controlling both geometric and propagation phases. As such, a metasurface that generates orbital angular momentum with distinct topological charges under oppositely incident right-handed circular polarization is designed. An additional rotational degree of freedom for elliptical polarization conditioning further enables direction-dependent holography, projecting the numerals “4” and “7” under illumination of elliptically polarized light with ellipticity π/6 and phase delay π/3. This design significantly expands polarization versatility while enabling compact and reconfigurable asymmetric wave manipulation, offering new opportunities for future applications such as directional wireless communications.