Fig. 4: Evolutions of the metasurface-generated PPBs corresponding to the points on HyOPS.

a The selected six points on HyOPS representing six states of PPBs generated successively by metasurface. b Six states of polarization (SOP) of the light incident on the metasurfaces are chosen to generate various states of PPBs corresponding to the coordinates in (a). c The measured annular intensity patterns of the output states corresponding to the points in a for PPB1 and PPB2 in the x–y plane after transmission through a vertical linear polarizer depicted by the white double arrow. These images are captured at the designed focal position z = 200 μm. Scale bar: 10 μm. d The calculated and measured polarization orientations and distributions of PPB1 and PPB2 corresponding to point II in (a). Note that the horizontal polarization orientation is defined as 0 rad. Scale bar: 10 μm. e Measured annular intensity patterns of the PPB1 and PPB2 in the x–y plane at the wavelengths of 480 nm (blue), 580 nm (yellow) and 630 nm (red) at a propagation distance of z = 230, 195, and 180  μm. These images are captured through a linear polarizer depicted by the white double arrow. Scale bar: 10 μm.