All-dielectric metasurface doublet enabling beam steering and polarizing beam splitting

Multifunctional metasurfaces, fulfilling a variety of tasks, have attracted drastically growing interest. Here we proposed and embodied an all-dielectric metasurface doublet (MD) by vertically concatenating twosome arrays of rectangular nanoresonators on either side of a quartz substrate, in which distinct phase profiles are encoded for orthogonally polarized light. Bifunctional beam manipulation including enlarged steering and polarizing beam splitting was enabled by the MD. The superior performance of the proposed device paves the way to largescale photonic integrated applications.