Fig. 1. Brief overview of the structure of the review.

Fig. 2. Achromatic computational imaging based on metasurface modulation techniques. EDoF-based achromatic imaging: (a) cubic phase mask, reproduced with permission from Ref. 30 (CC-BY), (b) symmetric EDoF-based canonical phase mask, reproduced with permission from Ref. 31 © 2020 Chinese Laser Press. Optimization-based inverse design methods: (c) multizone dispersion-engineered metalens-based achromatic RGB focusing, reproduced with permission from Ref. 32 (CC-BY), (d) achromatic RGB imaging with efficient 3D inverse design methods, reproduced with permission from Ref. 33 (CC-BY), (e) achromatic visible imaging with EDoF-based inverse design, reproduced with permission from Ref. 31 © 2021 American Chemical Society, and (f) achromatic inverse design based upon artificial neural network, reproduced with permission from Ref. 35 © 2021 Wiley-VCH.

Fig. 3. Spectral modulation-based hyperspectral imaging. Hyperspectral imaging with random encoding with (a) regular-shaped metasurface design, reproduced with permission from Ref. 2 © 2022 Optical Society of America, (b) freeform-shaped metasurface, reproduced with permission from Ref. 44 © 2022 Wiley-VCH, (c) metasurface-based gratings, reproduced with permission from Ref. 45 © 2022 Optica Publishing Group, (d) multi-aperture spectral filter array-based hyperspectral imaging, reproduced with permission from Ref. 46 (CC-BY), (e) end-to-end learned optimal metasurface design, reproduced with permission from Ref. 3 © 2022 IEEE.

Fig. 4. Polarization modulation-based computational metasurface imager. (a) Polarization multiplexing-based single-pixel imaging, reproduced with permission from Ref. 55 (CC-BY), (b) extreme-DoF imaging with polarization multiplexing, reproduced with permission from Ref. 59 (CC-BY), (c), (d) wide FoV microscopic imaging methods with polarization multiplexing, reproduced with permission from Ref. 58 (CC-BY) and Ref. 57 (CC-BY), (e) polarization multiplexing for underwater descattering, reproduced with permission from Ref. 56 © 2021 Wiley-VCH, (f) polarization multiplexing-based 4D imaging, reproduced with permission from Ref. 60 (CC-BY), (g) full-Stokes imaging, reproduced with permission from Ref. 4 © 2019 AAAS, (h) efficient polarization imaging with polarization splitting, reproduced with permission from Ref. 61 © 2020 Optical Society of America, (i) compressive polarization imaging with random weak dichroism metasurface, reproduced with permission from Ref. 5 (CC-BY).

Fig. 5. Depth modulation and imaging techniques with metasurface imager. (a) DH-PSF engineering-based depth imaging, reproduced with permission from Ref. 65 (CC-BY), (b) EDoF and DH-based PSF engineering, with side-by-side metalens, reproduced with permission from Ref. 66 © 2020 ACS, (c) depth from dual-defocus multiplexing, inspired by jumping spider vision, reproduced with permission from Ref. 67 (CC-BY), and (d) triple metalens based 3D positioning, reproduced with permission from Ref. 68 © 2020 Optica Publishing Group.

Fig. 6. Angle dimension modulation for computational imaging. Wide-angle-imaging-based upon: (a) ommatidia-inspired pixel-wise angle-sensitive filtering, reproduced with permission from Ref. 70 (CC-BY), (b) angle-selective metalens array, reproduced with permission from Ref. 71 © 2022 Optica Publishing Group, (c) synthetic aperture with four small apertures, reproduced with permission from Ref. 72 © 2021 Chinese Laser Press. Wide-angle illumination for 3D depth imaging based upon: (d) pseudo-random coding, reproduced with permission from Ref. 73 (CC-BY), (e) uniform dense light patterns, reproduced with permission from Ref. 6 (CC-BY), (f) double-zone illumination, reproduced with permission from Ref. 74 (CC-BY), and (g) dual depth imaging mode with structured light-field imaging under common light conditions and structured imaging under low-light conditions, reproduced with permission from Ref. 75 © 2022 Wiley-VCH.

Fig. 7. Spectrum-angle/depth modulation-based computational imaging: spectral-angle joint modulation for (a) RGB and depth imaging with EDoF, reproduced with permission from Ref. 89 © 2021 ACS, (b) spectral light-field imaging, reproduced with permission from Ref. 91 (CC-BY), (c), (d) high-efficiency color imaging based upon color routing, reproduced with permission from Ref. 93 (CC-BY) and Ref. 92 © 2021 ACS, (e) single-image multichannel imaging, reproduced with permission from Ref. 94 © 2022 Optica Publishing Group, and (f) full-color wide-FoV imaging, reproduced with permission from Ref. 95 (CC-BY).

Fig. 8. Computational imaging framework of metasurface-based imaging. (a) The computational imaging process, containing optimizable imaging component and reconstruction algorithms; (b) independent optimization framework; and (c) end-to-end optimization framework.

Fig. 9. Metasurface modulation-based computational sensing methods.

Table 1. Overall summarization of existing computational metasurface imager.