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