Dual-mode orbital angular momentum (OAM) base cell array and metasurface preparation method

A dual-mode orbital angular momentum (OAM) convergence base cell array, wherein the base cell array comprises 2n(2n−1) anisotropic cell structures and 2n isotropic cell structures;

• and the base cell array has an array structure of 2n×2n, n denoting a bit number;
• each of the anisotropic cell structures comprises a bottom ground layer, a dielectric substrate layer and a top pattern layer which are disposed in sequence from bottom to top, the top pattern layer of the anisotropic cell structure having an axisymmetric H-shaped structure;
• and
• each of the isotropic cell structures comprises a bottom ground layer, a dielectric substrate layer and a top pattern layer which are disposed in sequence from bottom to top, the top pattern layer of the isotropic cell structure having a square structure.