Fig. 2

The nanoimprint metalens arrays and the measurement results. a Optical photo of our nanoimprint metalens arrays. b The microscope photo. c Top-view SEM image of a portion of the metalens array. d Side-view SEM image with high magnification. e Normalized measured intensity distributions in the y-z plane of all 16 metalenses in the array. f The normalized measured focal plane intensity distribution of a single metalens. g The x-direction cross sections of the measured intensity profiles in (f). The solid green curve denotes the Airy fit of measured data (black square point). The green text gives the full widths at half-maximum (FWHM) of the fitting measured data. h Calculated MTF (solid green curve) of a single metalens. The dashed line represents the corresponding diffraction limit