Fig. 16: Performances of metalens-based telescopes.

a Schematic of planar Cassegrain telescope. b Imaging results of the Cassegrain telescope. Row 1: Photographs of slit objects, from left to right, the center-to-center distance of the slit is 200 μm, 150 μm, and 100 μm, scale bar: 100 μm. Row 2: Images results, from left to right, corresponding to the slit objects in row one, scale bar: 200 μm. c The energy flux of the typical metasurface Cassegrain telescope is depicted. d Schematic representation of the monolithic integrated telescope, which is constructed using cascaded metasurfaces. e The target, a number “four”, which is generated by a USAF 1951. f Measured results of the monolithic integrated telescope imaging. g Photograph of the telescope based on the metalens which is capturing the moon. h An IR image of the moon is captured. The camera is equipped with a 4 f system that magnifies the image by a factor of 2×. i Photograph of the meta-astrophotography apparatus. Inset: schematic of the meta-astrophotography apparatus. j Imaging results of the Moon at its last quarter phase. k Photograph of the MDL based telephoto camera. l RGB photograph of the moon. m Photograph of the metalens integrated telescopic system. n Enlargement of the moon image in the central FOV. o The current aperture size of several of the largest metalens telescope systems, compared with that of the Hubble Space Telescope (HST) and the James Webb Space Telescope (JWST). a, b Reprinted with permission from²⁵⁶. Copyright 2020 De Gruyter. c Reprinted with permission from²⁵⁷. Copyright 2021 Multidisciplinary Digital Publishing Institute. d–f Reprinted with permission from²⁵⁸. Copyright 2023 American Chemical Society. g, h Reprinted with permission from⁹⁵. Copyright 2023 American Chemical Society. i, j Reprinted with permission from⁹⁷. Copyright 2024 American Chemical Society. k, l Reprinted with permission from²⁶⁰. Copyright 2025 American Institute of Physics Publishing. m, n Reprinted with permission from²⁶¹. Copyright 2025 Springer Nature