Circular polarization multiplexing holography based on dielectric metasurface

To solve the problem that circular polarization multiplexing cannot be realized by a single phase control mode, a rectangular silicon brick structure was used to design a metasurface that could realize circular polarization multiplexing holography at 1.55 μm by combining transmission phase and geometric phase. The simulation results show that under the illumination of left circularly polarized light and right circularly polarized light, two clear holographic images can be observed in the far field, with transmission efficiency of 60.8% and 61.5%, and polarization conversion efficiency of 79.1% and 78.7%, respectively. The designed circularly polarized multiplexing metasurface has the advantages of weak crosstalk, independent design of two channels, and simple design. Moreover, the metasurface components are small in size, light in weight, easy to integrate, and have great application potential in information reuse, information storage or encoding, anti-counterfeiting, and other aspects.