Frequency-and-spin Multiplexed Multifunctional Metadevices

Abstract

Achieving kaleidoscopic wavefront controls or versatile distinct multifunctions with a thin flat plate are pivotal yet challenging in integrated optics. Anisotropic metasurface affords us an efficient recipe primarily for arbitrary linear polarization, but is ceased to be efficient for multiple functionalities at arbitrary spin states. Here, we report a strategy for multitasking in a shared aperture by involving split ring resonators (SRRs) and cross bar operated at low and upper frequencies in an emerging chessboard-configured meta-atom. By individually rotating the SRRs with endowing geometric phase, two similar functions with flipped phases are realized at low band under two circularly polarized waves, whereas by involving both orientation and structural variations of cross bars (geometric and propagation phase), two independent optical functions can be engineered at high frequency. The key for such multitasking benefits from the totally suppressed interference between both structures and the completely spin-decoupled dual-phases at high frequency. To verify the significance of our approach, a proof-of-prototype sample is demonstrated for wavefront manipulation by integrating quad vortices and two-dimensional holograms, etc. Our finding in frequency-and-spin multiplexing is expected to trigger great interest in high electromagnetic/optical integration with boosted information capacity and a new degree of freedom.