Independent Control of Co-polarized and Cross-polarized Light Using Metasurface for Vector Vortex Beam Generation

We present a metasurface design for generating multi-channel vector vortex beams through simultaneous control of phase and polarization states. The metasurface consists of nested silicon nanopillars on a SiO2 substrate, designed to operate at 800 nm wavelength. By implementing independent control of deflection phase, lens phase, and vortex phase for each channel, we achieve the generation of dual-channel vector vortex beams with different topological charges. Numerical simulations demonstrate successful generation of vector vortex beams in separate channels, with both identical (l = 1) and different (l = 1 and l = 2) topological charges. The simulation results show well-defined doughnut-shaped intensity profiles and precise polarization control for each channel at the focal plane, confirming our design's capability for complex beam manipulation in multiple channels.