Fig. 9: Images of fabricated metalenses and fabrication methods via the TPP technique.

a SEM image of the fabricated IP-Dip stacked diffractive doublet lens with supporting wall. b SEM image of the fabricated IP-Dip multilayer achromatic metalenses with supporting wall. c SEM image of the fabricated HAMLs, including 80 μm diameter merged HAML (upper left), 40 μm diameter merged HAML (upper right), 40 μm diameter air-spaced (lower left) HAML, and 20 μm diameter merged HAML (lower right), all with different sizes of IP-Dip nanopillars and different heights IP-Dip phase plates. d SEM image of the fabricated metalens with different heights of IP-Dip nanoholes and phase plates, scale bar: 3 μm. e SEM image shows the fabricated metalens with IP-L helical nanostructures with different orientations. f SEM image of the fabricated metalens, with a magnified view reveals the details of the 3D variable zirconium–silicon hybrid sol–gel nanobricks. g SEM image of the MLD array on the surface of CMOS sensor(left). The single IP-S MLD is imaged by SEM (upper right) and directly by the CMOS sensor (lower right). h SEM image shows a SMF (red) aligned with a free-form optical surface exhibiting a saddle-type shape. The polarization control is achieved through the presence of an IP-Dip chiral photonic crystal structure (blue). Additionally, beam shaping is facilitated by incorporating an IP-S free-form lens structure equipped with a Fresnel zone plate (green), scale bars: 25 mm. i SEM image of the fabricated metafiber with high AR IP-L nanopillar with different sizes. j SEM image of the fabricated metafiber with IP-Dip concentric nanorings. k SEM image of the fabricated metafiber with different heights of IP-Dip nanocubes, scale bar: 25 μm. l SEM image of the fabricated metafiber with adaptive heights of IP-Dip nanocubes, scale bar: 20 μm. m SEM images of the fabricated metafiber with the IP–Dip ellipsoidal-shaped tip nanopillars. n Upper: SEM image shows the influence of the exposure laser power on the pillar width. Center: SEM image shows the multilevel printed nanopillars of increasing height. Lower: SEM image of the fabricated matrix for the evaluation of nanopillars with different AR, the diameter of the nanopillars is fixed at 0.6 μm, the pitch equals the unit cell width of 0.8 μm. IP-Dip is the material for all nanopillars. o Configuration of the parallel 3D projection TPL system and the generation of independently controlled laser foci, TL tube lens, MLA microlens array, DM dichroic mirror, OB objective lens. p The unit nanostructures of metalens whose sizes can be adjusted by the pixel number. q SEM image of the fabricated SU-8 nanopillar array with various pixel numbers, scale bar: 20 μm. r SEM image of the fabricated metalens stitched by 3 × 3 arrays of 80 × 80 SU-8 nanopillars, scale bar: 50 μm. s A zoom-in and tilted view of (r), scale bar: 20 μm. a Reprinted with permission from ref. ¹⁸⁵. Copyright 2019 Optica Publishing Group. b Reprinted with permission from ref. ¹⁸⁶. Copyright 2023 American Association for the Advancement of Science. c Reprinted with permission from ref. ¹⁸⁷. Copyright 2020 Springer Nature. d Reprinted with permission from ref. ¹⁸⁸. Copyright 2021 De Gruyter. e Reprinted with permission from ref. ¹⁸⁹. Copyright 2019 John Wiley and Sons. f Reprinted with permission from ref. ¹⁹⁰. Copyright 2023 John Wiley and Sons. g Reprinted with permission from ref. ¹⁹⁵. Copyright 2021 Springer Nature. h Reprinted with permission from ref. ¹⁹⁷. Copyright 2016 Springer Nature. i Reprinted with permission from ref. ¹⁹⁸. Copyright 2022 Springer Nature. j Reprinted with permission from ref. ¹⁹⁹. Copyright 2021 American Chemical Society. k Reprinted with permission from ref. ²⁰⁰. Copyright 2021 Springer Nature. l Reprinted with permission from ref. ²⁰¹. Copyright 2024 Optica Publishing Group. m, n Reprinted with permission from ref. ²⁰². Copyright 2024 Optica Publishing Group. o–s Reprinted with permission from ref. ²⁰³. Copyright 2024 Optica Publishing Group