Fig. 3: Concept of chiral gradient metasurfaces.
From: Chirality encoding in resonant metasurfaces governed by lattice symmetries
a Schematic illustration of the chiral gradient metasurface with bar resonators arranged in a square lattice. The rotation angle β of the resonator within the unit cell varies smoothly along the chip coordinate. The color of the bars encodes the chiral signal characteristic for the corresponding β. b Optical image of the fabricated chiral gradient metasurface based on Ge resonators on CaF2 substrate. The insets show the SEM images, with six unit cells each, taken at different coordinates along the chiral gradient stripe. Gray dashed line indicates the signal collection area that is scanned along the gradient stripe during the measurement. c Comparison of simulated chiral signal map (left) and the experimentally measured dependence of chiral signal on the coordinate along the chip (right).
