Fig. 1. Process of imaging development. (a) Negative refraction left-handed material^[40]; (b) metalens structure^[41]; (c) 2D microwave cloaking^[42]; (d) V-shape antenna^[8]; (e) resonant phase metasurfaces^[43]; (f) geometric phase metasurfaces^[46].(g) propagation phase metasurfaces^[17]

Fig. 2. Achromatic lenses based on metasurfaces. (a) multi-wavelength achromatic metasurfaces^[62]; (b) multi-wavelength achromatic metasurfaces in layered structures^[63]; (c) narrow-band achromatic metalens^[64]; (d) infrared broadband achromatic metalens^[65]; (e)visible broadband achromatic metalens^[66]; (f) polarization-insensitive achromatic metalens^[67]

Fig. 3. Metasurface-based spectral imager and imaging principle. (a) Schematic diagram of the spectral imager^[69]; (b) line-scan folded metasurfaces hyperspectral imaging^[69]; (c) single nanowire metasurfaces spectrometer^[70]; (d) multi-aperture parallel superstructure surface snapshot imaging system^[71]; (e) snapshot hyperspectral imager^[72]

Fig. 4. Polarization imaging based on metasurfaces. (a) Split-focal plane polarization camera^[73]; (b) full Stokes polarization image^[74]; (c) crosstalk-free achromatic full Stokes imaging^[75]; (d) staggered metalens full Stokes polarization imaging^[76]; (e) spectral and polarized metalenses^[77]

Fig. 5. Metasurfaces for structured light 3D imaging. (a) Active tunable metasurfaces based on TCO materials^[81]; (b) MEMS-based metasurfaces for 3D imaging^[82]; (c) multimode optical fiber high frame rate 3D imaging^[83]; (d) full-space random point cloud projection 3D imaging^[86]; (e) large field-of-view point cloud projection 3D imaging^[87]; (f) large field-of-view high-density point cloud projection 3D imaging^[88]

Fig. 6. Passive 3D imaging. (a) Underwater binocular metasurfaces^[90]; (b) full-color achromatic metasurfaces^[91]; (c) three-dimensional single-particle tracking of light-field metasurfaces^[92]; (d) aberration-corrected three-dimensional localized metasurface-based lens array^[93]

Fig. 7. Back-end imaging of metasurfaces. (a) Dual-aperture metasurfaces imaging system^[95]; (b) metasurface-based depth sensor^[96]; (c) SLIM imaging system^[97]; (d) metasurfaces-based single-stripe projection imaging system^[98]; (e) real-time programmable metasurface imager^[94]

Fig. 8. End-to-end based metasurfaces. (a) Polarization-insensitive visible metasurfaces^[99]; (b) flowchart for co-optimization of multi-channel imaging^[100]; (c) flowchart for end-to-end design of multifunctional metasurfaces^[101]; (d) compact snapshot hyperspectral imaging system^[102]

Fig. 9. AR/VR display system. (a) Transmissive full-color AR near-eye display^[104]; (b) achromatic metalens to achieve VR near-eye display^[105]; (c) reflective retinal display^[106]; (d) Metaform micro-imaging^[107]; (e) contact lens-based near-eye display^[108]; (f) dynamically adjustable AR display^[109]

Fig. 10. Applications of fiber/optical waveguides. (a) Propagation coupling of phase-gradient metasurfaces to control waveguide modes^[110]; (b) endoscopic optical imaging^[111]; (c) high-speed switchable wavefront shaping at the GHz level^[112]; (d) full-color 3D holographic AR display^[113]

Fig. 11. Super-resolution imaging and quantum imaging based on metasurfaces. (a) Schematic diagram of metasurfaces^[114]; (b) metasurface-assisted confocal imaging system^[114]; (c) metasurface-based modulated wave source^[115]; (d) optical imaging based on quantum entanglement of polarized metasurfaces^[117]; (e) metasurfaces used for fringe imaging^[118]; (f) high-dimensional multiphoton quantum source based on metasurface metalens array^[119]