Fig. 5: Edge detection of phase objects.
From: Compact meta-differentiator for achieving isotropically high-contrast ultrasonic imaging
Ideal phase object in the shape of the numeral 2 with (a) a phase delay of 2π/3 and (b) a phase advance of 2π/3 in relation to the ambient medium. Middle and right panels: simulated acoustic intensity and phase distributions at the output plane. c, d Similar to (a, b), but for the full-wave simulated phase objects made of resin material with a thickness of 1.2 mm. c shows a hollow pattern of the numeral 2 at the center, while panel (d) shows the complementary physical numeral 2. e, f Same as (c, d), but for the fabricated phase object samples made of the same material and parameters as in (c, d).
