Fig. 4. Merged metasurfaces for chiral holograms.

a Illustration of the chiral metasurface hologram merging subarray A and subarray B to enable spin-controlled wavefront shaping. Subarrays A and B are composed of stepped nanoapertures in Form A and Form B, contributing to the images “owl” and “window”, respectively. b Partial SEM image of the merged metasurface corresponding to a. Scale bar: 500 nm. c Reconstructed images for the chiral metasurface hologram at 820 nm. The polarization states of the incident beam are RCP, right-handed elliptically polarized, linearly polarized, left-handed elliptically polarized, and LCP from left to right. Scale bar: 10 μm. d Captured holographic images at different wavelengths of 720 nm, 770 nm, 820 nm, 845 nm, and 870 nm under RCP (top row) and LCP (bottom row) incidence. Scale bar: 10 μm