Fig. 6

Vortex beam generator (a) Under x-polarized and y-polarized incidence at a frequency of 1.234 THz. (b) Reflection amplitude and phase variations with different side lengths of diamond-shaped blocks under x-polarized and y-polarized incidence. (c) Simulated 2D near-field and (d) 3D far-field electric field distributions under x-polarized incidence. (e) Simulated 2D near-field and (f) 3D far-field electric field distributions under y-polarized incidence.