Fig. 1. Schematic of the structure of LC coding metasurface unit cell

Fig. 2. Flowchart of genetic algorithm for reverse design of LC coding metasurface unit cell

Fig. 3. Schematic structure of coding metasurface unit cell with topological optimization design

Fig. 4. Reflection amplitude and phase response of the metasurface unit cell at LC effective dielectric constants ε of 2.55, 2.95, 3.15, and 3.65, respectively. (a) Reflection amplitude; (b) phase response

Fig. 5. Flowchart of genetic algorithm for reverse design array coding sequence

Fig. 6. Array coding sequence and corresponding far-field scattering results under different θobj, φobj. (a)(d) θobj, φobj is (10°, 315°); (b)(e) θobj, φobj is (20°, 120°); (c)(f) θobj, φobj is (30°, 220°)

Fig. 7. Array coding sequence and far-field scattering results for different beams. (a)(d) Triple beams with θobj, φobj of (15°, 60°), (15°, 180°), and (15°, 300°); (b)(e) quadruple beams with θobj, φobj of (0°, 0°), (25°, 60°), (25°, 180°), and (25°, 300°); (c)(f) quintuple beams with θobj, φobj of (20°, 18°), (20°, 90°), (20°, 162°), (20°, 234°), and (20°, 306°)

Fig. 8. Array coding sequence and far-field scattering results for different quintuple beams. (a)(d) Quintuple beam with θobj, φobj of (15°, 0°), (20°, 90°), (25°, 150°), (25°, 210°), and (20°, 270°); (b)(e) quintuple beam with θobj, φobj of (10°, 45°), (30°, 135°), (30°, 180°), (30°, 225°), and (10°, 315°); (c)(f) quintuple beam with θobj, φobj of (20°, 0°), (20°, 120°), (20°, 150°), (20°, 210°), and (20°, 240°)

Fig. 9. Vortex phase distribution under different topological charges. (a)(d) l=±1; (b)(e) l=±2; (c)(f) l=±3

Fig. 10. Far-field scattering intensity, phase results, and corresponding pattern purity distribution diagrams at 0.394 THz. (a)(d)(g) l=-1; (b)(e)(h) l=-2; (c)(f)(i) l=-3

Fig. 11. Far-field scattering intensity, phase results, and corresponding pattern purity distribution diagrams at 0.394 THz. (a)(d)(g) l=+1; (b)(e)(h) l=+2; (c)(f)(i) l=+3

Fig. 12. Top view of far-field scattered intensity, front view of far-field scattered intensity, and phase results for different beams. (a)-(c) Double vortex beams (l=+3) with θobj, φobj of (15°, 45°) and (25°, 180°); (d)-(f) triple vortex beams (l=+2) with θobj, φobj of (15°, 60°), (15°, 180°), and (15°, 300°); (g)-(i) quadruple vortex beams (l=-2) with θobj, φobj of (0°, 0°), (25°, 60°), (25°, 180°), and (25°, 300°); (j)-(l) quintuple vortex beams (l=-1) with θobj, φobj of (20°, 18°), (20°, 90°), (20°, 162°), (20°, 234°), and (20°, 306°)