Fig. 1. Design concept of the SPMM device. The light from photographic scenes contains spectrum- and elliptic polarization-related information that is usually lost or ignored in traditional imaging systems. Our multi-foci metalens (inset) generates twelve foci/images corresponding to six spectral bands and two circular polarization states, thereby permitting the reconstruction of these lost features.

Fig. 2. Design and realization of the SPMM.(a, b) The metalenses designed for RCP (or LCP) based on the holography principle possess six working wavelengths and six corresponding off-axis foci at different positions on the same focal plane. (c) The SPMM with twelve different foci was acquired by mixing nanostructures of these two metalenses together randomly. (d, e) The simulated cross-polarization conversion efficiencies (d) and phase retardation (e) corresponding to six discrete wavelengths. The materials of the nanostructure and substrate were SiN_x and SiO_2, respectively. h=600 nm, w=130 nm, l=323 nm, and p=450 nm. (f) The SEM images of the fabricated metasurface (scale bar 2 μm). The fake color represents randomly mixed nanostructures. An optical inset shows the whole SPMM, which is 500 μm in diameter (scale bar 50 μm).

Fig. 3. Design and experimental focusing/imaging results for the SPMM.(a) The sketch map of optical setup with laser source (SeeFig. S4(a) in Supplementary information for detailed description). (b) The positions of the twelve foci of the SPMM. (c) The wavelength dependency of the normalized total intensity of light spots at positions F(λ_n, L or R) within 10 μm. (d) Illustration of the experimental imaging progress. (e) The focusing results of the SPMM for the incident light beam consisted of six wavelengths. The diameter of each enlarged sliced illustration is 35 μm. (f) Typical imaging results of the SPMM for the incident light beam consisted of six wavelengths. The diameter of each sliced illustration is 35 μm.

Fig. 4. Polarization-dependent focusing and imaging using the SPMM. (a) The relationship between normalized intensities I_RCP (or I_LCP) of RCP (or LCP) light and the polarization parameter η in the Jones matrices. (b) The contrast calculated by (I_RCP−I_LCP)/(I_RCP+I_LCP). (c) Typical polarization state measurement results at 500 nm, with the polarization state of the incident light beam varied gradually from LCP to RCP. The intensity of the focus at positionF(500 nm, R) increases from zero to maximum, with this trend reversed at F(500 nm, L). (d) Imaging results achieved by the SPMM at a wavelength of 540 nm.

Fig. 5. Multispectral and polarized imaging using the SPMM with ordinary white light beams. (a) Schematic illustration of the experiment. (b–d) Imaging results for a color picture consisting of four flags. The light source is a halogen lamp, and its spectrum is presented in (c). (e–g) Imaging results for the phrase "HUST", with the spectrum of a mobile phone flashlight that was used as the light source. (h) Histogram of the reconstructed spectra based on six regions marked with dash lines in (g). (i, j) Regular optical image and the SPMM imaging results for a transparent plastic stick. (k, l) A pair of typical images with the same spectral band are enlarged. (m) The reconstructed polarization ellipticity image can be calculated from the SPMM imaging results in (j). The images of corresponding opaque patterns are marked with dashed lines.