Fig. 3: Characterization of metasurfaces for the generation of arbitrary POVs.
From: Broadband generation of perfect Poincaré beams via dielectric spin-multiplexed metasurface
a Top: measured intensity distributions of the four optical vortices with a linear scale in the y–z plane at a design wavelength of 530 nm: \(|{{\rm{POV}}}_{{\mathrm{R}}},1\rangle\) and\(|{{\rm{POV}}}_{{\rm{L}}},5\rangle \) corresponding to the metasurface MF1; \(|{{\rm{POV}}}_{{\rm{R}}},5\rangle \) and \(|{{\rm{POV}}}_{{\rm{L}}},10\rangle \) corresponding to the metasurface MF2. Bottom: measured annular intensity profiles of four optical vortices at the designed focal position z = 200 μm. Scale bar: 10 μm. b Normalized cross sections of the annular intensity profiles of the four optical vortices along the white dash and solid lines of a for MF1 (top) and MF2 (bottom). c, d Top: measured normalized intensity distributions of the optical vortices with a linear scale in the y–z plane at the wavelengths of 480 nm (blue), 580 nm (yellow) and 630 nm (red). Each wavelength corresponds to two orthogonally circular polarization optical vortices (c: \(|{{\rm{POV}}}_{{\rm{R}}},1\rangle \) and \(|{{\rm{POV}}}_{{\rm{L}}},5\rangle \) for metasurface MF1; d: \(|{{\rm{POV}}}_{{\rm{R}}},5\rangle \) and \(|{{\rm{POV}}}_{{\rm{L}}},10\rangle \) for metasurface MF2). Bottom: measured annular intensity profiles of optical vortices at the propagation distances z = 230 μm, 195 μm, and 180 μm corresponding to the wavelengths of 480 nm (blue), 580 nm (yellow) and 630 nm (red). Scale bar: 10 μm.
