Fig. 1. Conceptualization of the plasmonic metasurface for generating a complete polarization set. (a) Illustration of the Au-SiO₂-Au metasurface that reflects and additionally splits a CP incident beam into six spatially separated channels, each featuring a specific polarization state. The polarization states change to their orthogonal counterparts when the spin of the incident light is reversed. The RCP incidence generates spots Sp₂, Sp₃, Sp₄, Sp₅, Sp₆, and Sp₈, respectively, whereas LCP incidence produces spots Sp₂, Sp₄, Sp₅, Sp₆, Sp₇, and Sp₈, respectively. The absolute values of polar angles for deflected LP and CP spots are around 15.4° and 22.1°, respectively, at the design wavelength of 850 nm. (b) Top view of a metasurface segment that consists of six different kinds of interleaved meta-pixels with the mirror (empty spaces), HWP (bricks, marked in red), and QWP (crosses, marked in blue color) functionalities. The mirror and HWP meta-pixels produce co-polarized and cross-polarized circular polarization states, respectively, while the QWP meta-pixels, differentiated by four distinct orientations, generate four unique linear polarization states. |x>, |y>, |a>, and |b> represent horizontal, vertical, 45°, and −45° linear polarizations, respectively. For illustrative purposes, each meta-pixel is reduced to 4 × 4 meta-atoms. The change of spin due to reflection is not considered here.

Fig. 2. Performance of the meta-atoms under RCP incidence. (a) Simulated reflection amplitude and phase of the four HWP meta-atoms with different orientations at the design wavelength of 850 nm. (b) Simulated diffraction efficiencies of the HWP supercell, shown in the inset, as a function of wavelength. (c) Simulated reflection amplitude and phase of the four QWP meta-atoms at the design wavelength of 850 nm. (d) Simulated diffraction efficiencies of the QWP supercell, shown in the inset as a function of wavelength. The dimensions of all selected meta-atoms are shown in Table S1.

Fig. 3. Optical microscope (a) and SEM (b–g) images of the fabricated metasurface. The scale bars in (c–g) are 1 µm. The meta-pixels shown in (c–g) generate respectively the reflection of LCP (RCP) at 45° (135°), |a> (|b>) at 180°, |b> (|a>) at 0°, |x> (|y>) at 90° and |y> (|x>) at 270° under the RCP (LCP) incidence.

Fig. 4. Experimental demonstration of spin-controlled polarization set generation at the design wavelength of 850 nm. (a–d) Polarization-resolved intensity profiles. The feature spots are marked as Sp₂-Sp₈ for future analysis. (e) Polar plots of the RCP (blue) and LCP (red) incident beams. (f, h, j, and l) Polar plots of the diffracted LP beams (Sp₂, Sp₄, Sp₆, and Sp₈) from the QWP meta-pixels with cross arms oriented at −45° (f), 0° (h), 90° (j), and 45° (l), respectively. The AoLPs are rotated by 90° once the incident light is switched from RCP to LCP. (g, k) Polar plots of the diffracted CP beams (Sp₃ and Sp₇) from the HWP meta-pixels. Only the cross-polarized CP beam is visible, with its handedness altered by the spin of incident light. (i) Polar plot of reflected CP beams (Sp₅) with co-polarization states from the mirror meta-pixels.

Fig. 5. Operation performance of the metasurface for y-polarized incident light at the design wavelength of 850 nm. (a–d) Polarization-resolved intensity profiles. The feature spots are marked as Sp₂-Sp₈ for future analysis. (e) Polar plot of the y-polarized incident beam. (f, l) Polar plots of the diffracted elliptically polarized beams (Sp₂ and Sp₈) from the QWP meta-pixels with cross arms oriented at −45° (f) and 45° (l), respectively. (g, k) Polar plots of the diffracted CP beams (Sp₃ and Sp₇) from the HWP meta-pixels. Both LCP and RCP beams are visible, each receiving half of the power as the incoming light splits. (h, j) Polar plots of the diffracted y-polarized beams (Sp₄ and Sp₆) from the QWP meta-pixels with cross arms oriented at 0° (h) and 90° (j), respectively. (i) Polar plot of the reflected y-polarized beam (Sp₅) from the mirror meta-pixels.