High-efficiency transmissive metasurface for dual-polarized dual-mode OAM generation

In this paper, a high-efficiency dual-polarized transmissive metasurface is presented for the generation of dualmode convergent orbital angular momentum (OAM) beams. The proposed transmissive metasurface is composed of dual-polarized metasurface units, which are constructed from four stacked patches coupled through a Jerusalem-cross aperture on the interlayer ground, to complete the phase modulation for the orthogonal polarizations. The proposed transmissive metasurface units can achieve full 2p phase modulation along with low transmission loss. Converged OAM beams with modes numbers l(x) = +1 and l(y) = -2 are thus stimulated through the proposed transmissive metasurface for both orthogonal polarizations, which have been demonstrated numerically and experimentally.