Fig. 4. Metasurfaces for simultaneous control of phase and polarization. (a) Schematic of the dual-layer plasmonic metasurfaces composed of rectangular nano-apertures. (b) The diagram for the full control of polarization and phase, in which 36 pairs of nano-apertures with different parameters are used. (c) SEM image and (d) measured far-field intensity profiles of the plasmonic metasurfaces to generate a radially polarized beam. (e) Schematic of the unit cell for dielectric metasurfaces. (f) Sketch map of a focusing lens combined with a quarter-waveplate. (g) Illustration of the unit cell of a meta-hologram to generate a holographic image with spatially varying polarization states. Three parameters, including local displacement s, global displacement p and orientation angle ψ of two orthogonal Au nanorods can be used to simultaneously control the phase and polarization. (h) Experimental demonstration of vectorial holography. Four sets of diatomic meta-molecules are arranged in sequence, then each letter in holographic image represents one single specific polarization. (a–d) Reproduced with permission.¹⁰⁴ (e and f) Reproduced with permission.¹⁰⁷ (g and h) Reproduced with permission.¹⁰⁹.