Four-function metasurface based on a tri-band integrated meta-atom for full space control of circularly polarized waves

Highly integrated planar meta-devices have attracted much attention in optics and communication, which can achieve multitasking wavefront manipulations at multiple frequencies. Integrated meta-devices can increase data capacity and functional diversity. However, further expansion of functions in integrated devices is still challenging. Here, a multilayer geometric phase metasurface is proposed. The functions are expanded via decoupling the resonance of different layer structures or decoupling its phase modulation. Under circularly polarized (CP) wave incidence, the proposed multifunctional metasurface performs four functions at three distinct frequencies. When left-handed circularly polarized (σ+ CP) waves at 8 GHz is incident from the lower half of space, deflection is realized. When a CP wave with different handedness at 10 GHz is incident from the upper half of space, focusing and diverging lenses are realized, respectively. When σ+ CP waves at 17 GHz is incident from the lower half of space, the reflective holography is realized. We designed, manufactured, and experimentally proved the multifunctional integrated full-space metasurface. The simulation and measurement results are in good agreement, verifying the four-function and tri-band metasurface design strategy. The method proposed in this paper opens up a new opportunity for increasing the information capacity and has application prospects in communication systems, optical storage, and image display.