Fig. 4. Experimental demonstration of the MCP metasurface for the multiplexed manipulation of OAM and wavelength.

a Plane and OAM waves propagate normally into the MCP metasurface with two wavelengths (red: 633 nm, blue: 473 nm). b Upper: The metasurface and its SEM image. Lower: SEM images of the sample (φ₁ = φ₃ = 0° and φ₂ = φ₄ = 90°). The colors we add (red and blue) correspond to the working wavelengths. c Printing and holographic images are reconstructed by one MCP metasurface. Left: a binary image and a grayscale image. The scale bar is 100 µm. Right: different Latin letters reconstructed by incident OAM waves with different topological charges (l = −6, −3, 3, 6) and wavelengths. The scale bar is 70 µm. For clear display, the printing images show the intensity corresponding to the wavelength, and the holograms only show the intensity with white