Fig. 1. Schematic diagram of a reflective metasurface generating a perfect vortex beam.

Fig. 2. Generation of perfect vortex beam phase profile. (a) The phase profile generation method of the perfect vortex beam based on BBK when r₀ = 0.1 and l = 3. (b) The phase profile generation method of 2 × 2 perfect vortex beam arrays based on Dammann grating when r₀ = 0.04, l = 1, and p = 9.5 µm.

Fig. 3. Simulation results of perfect vortex beams with different topological charges. (a)–(f) x–y plane electric field strength distributions at z = 300 µm for topological charges of l = −3, −2, −1, 1, 2, 3, respectively. (g)–(l) x–z plane electric field strength distributions for topological charges of l = −3, −2, −1, 1, 2, 3, respectively. (m)–(r) Interference results of a perfect vortex beam with a spherical wave for topological charges l = −3, −2, −1, 1, 2, 3, respectively.

Fig. 4. Simulation results of perfect vortex beam control with different parameters r₀. (a)–(d) Electric field intensity distributions in x–y plane when r₀ = 0.04, 0.06, 0.08, 0.1. (e)–(h) Electric field intensity distributions in x–z plane when r₀ = 0.04, 0.06, 0.08, 0.1.

Fig. 5. Simulation results of perfect vortex beams for 2 × 2 arrays generated by Dammann gratings with different periods. (a)–(d) Phase profile distributions for l = −1, p = 9.5 µm, l = 1, p = 9.5 µm, l = −1, p = 19.5 µm, l = 1, p = 19.5 µm. (e)–(h) Distributions of electric field strengths in the x–y plane for l = −1, p = 9.5 µm, l = 1, p = 9.5 µm, l = −1, p = 19.5 µm, l = 1, p = 19.5 µm.

Fig. 6. Experimental test results of a perfect vortex beam and SEM image of the prepared metasurface sample. (a) Experimental setup diagram. (b)–(g) Experimental results with topological charges of 1, −1, 2, −2, 3, and −3, respectively. (h), (i) Experimental results of a perfect vortex beam array. (j) SEM image of the prepared metasurface sample. (k) Local SEM magnification image. (l) Comparison of experimental and simulated diameter data. (m) Comparison of the perfect vortex beam ring width results between experiments and simulations. (n)–(q) The perfect interference results of vortex beams and spherical waves.