Fig. 4 |. Fabrication and characterization of the meta-imager.

a,b, Optical images of the fabricated metasurfaces comprising the meta-imager. The inset is a scanning electron microscopy image of each metasurface. Scale bar, 5 μm. c, An ideal optical kernel calculated using the angular spectrum propagation method. The weight of each spot is equal to the predesigned digital kernel. d, Measured intensity profile of the kernel generated by the fabricated meta-optic. e, Comparison between convolutional results based on the ideal and measured kernels. The dashed white line indicates the sampled pixels for comparison. The demonstration kernel is the same as those in c and d.