Fig. 2: Theoretical analysis of isotropic spatial differentiation.
From: Compact meta-differentiator for achieving isotropically high-contrast ultrasonic imaging
Acoustic intensity and phase distributions of the PSF for the (a) focus metasurface and (b) spatial differentiator. c Intensity profiles along the vertical direction of the two PSFs. d An amplitude object in the shape of the numeral 2 with a height of 6λ, a width of 3.75λ, and a slit of 0.75λ placed at the input plane. Acoustic intensity and phase profiles at the output plane obtained through the (e) angular spectrum method and (f) convolution method.
