The 3D and 2D far-field scattering patterns of coding metasurfaces 3 and 4 at 1.2 THz.(a) Coding metasurface 3 with pre-designed coding sequence of 0, 1, 2, 3, 4, 5, 6, 7/4, 5, 6, 7, 0, 1, 2, 3 along x-direction.(b) Coding metasurface 4 with pre-designed coding sequence of 0, 1, 2, 3, 4, 5, 6, 7/4, 5, 6, 7, 0, 1, 2, 3 along y-direction.