Spin- and Space-Multiplexing Metasurface for Independent Phase Controls of Quadruplex Polarization Channels

Spin-decoupled metasurfaces can realize independent phase controls of two orthogonally circularly polarized (CP) waves, and hence have attracted much attention in recent years. However, all previously reported metasurfaces capable of simultaneously manipulating the transmission and reflection of CP waves can only achieve two decoupled polarization conversion channels. In this work, a spin- and space-multiplexing metasurface is proposed, that can achieve independent phase controls of four different CP conversion channels, including two cross-polarized transmission channels and two co-polarized reflection channels. The performance of the metasurface is experimentally validated by multi-channel independent holographic imaging. The results show that four independent holograms are realized in four CP conversion channels by only using a single metasurface, which can greatly improve the information capacity of the metasurfaces and make full use of polarization and space resources.

Automated summary

Spin-decoupled metasurfaces have attracted much attention for their ability to independently control the phase of two orthogonally circularly polarized waves. However, previous metasurfaces could only achieve two decoupled polarization conversion channels. This study proposes a spin- and space-multiplexing metasurface that can independently control the phase of four different circular polarization conversion channels. Experimental validation using multi-channel independent holographic imaging shows the potential to greatly improve information capacity and utilize polarization and space resources effectively.