Fig. 11

(a) Schematic of the sun’s annual trajectory over Wuhan. (b) Experimental demonstration of the Fourier meta-lens with oblique incidence. (I) Measured and simulated foci offset with different incident wavelengths and angles. (II) Intensity distribution of the focal images for different incident angles and wavelengths. (c) Schematic (I) and side view (II) of a single-layer planar meta-lens with an ultrawide FOV. Inset: meta-atom configuration. Simulated focal spots (III), Strehl ratio, and focusing efficiency (IV) at different angles of incidence. (d) Schematic of focusing on- and off-axis light by a metasurface doublet lens (left side of (I)) comprised of dielectric meta-atoms (right side of (I)). Simulated (top row of (II)) focal intensity profiles, measured (middle and bottom row of (II) for TE and TM mode) and measured focusing efficiency (III) of the metasurface doublet lens for different incident angles. (e) A schematic of the meta-lens doublet (I) comprising two meta-lenses: aperture meta-lens (depicted in orange of (II)) and focusing meta-lens (depicted in light blue of (II)), where each meta-lens consists of an array of rotated nanofins (bottom line of (II)). (III) Ray diagram for diffraction-limited focusing along the focal plane. Inset: magnified plots near their focal planes. (f) (I) Schematic of the optical setup for characterization. Normalized point spread function images and intensity distributions (second column of (II)) measured in the focal plane for angles of incidence of 0°, 30°, and 50°. (III) Focusing efficiency and FWHM of the point spread function as a function of the angle of incidence. (b) Reproduced with permission [100]. Copyright 2018, Wiley-VCH. (c) Reproduced with permission [174]. Copyright 2020, ACS. (d) Reproduced with permission [207]. Copyright 2016, NPG. (e) Reproduced with permission [153]. Copyright 2017, ACS. (f) Reproduced with permission [208]. Copyright 2021, ACS