Fig. 5: Singlet meta-imager for edge detection.
From: Ultracompact meta-imagers for arbitrary all-optical convolution
a Sketch for singlet meta-imager with the object and image distances labeled in l1 and l2, respectively. b Phase and amplitude profiles of the meta-imager realizing the edge detection. Its phase is obtained by adding both phases of metalens (f = 2.5 mm) and meta-modulator. The amplitude modulation comes from only the meta-modulator part because the metalens has an amplitude of 1. Scale bars: 100 μm. c Microscopic (left) and SEM (right) images of our fabricated singlet meta-imager with five discretized amplitudes. These amplitude profiles of 1, 0.75, 0.55, 0.3, and 0 are realized by using the nanobricks with (W = 110 nm, L = 160 nm), (W = 110 nm, L = 150 nm), (W = 110 nm, L = 140 nm), (W = 110 nm, L = 130 nm) and (W = 150 nm, L = 150 nm), respectively. Scale bars: 100 μm (left panel) and 300 nm (right panel). d Transmitted (cross-polarized part) pattern of the singlet meta-imager under the circular-polarization illumination. Scale bar: 100 μm. e Experimental (triangles) and simulated (curves) amplitude profiles along the line HH′ (see (b, d)). The experimental amplitude profiles are extracted from the measured transmission. f–h Characterization of edge detection by using the singlet meta-imager. The original binary-amplitude object f is located at the input plane of the singlet meta-imager, which yields the experimental (g) and simulated (h) edges with M = 1. Scale bars: 10 μm. i Experimental (dots) and simulated (curves) intensity profiles along the line II′ (see (g, h))
