Fig. 1. Schematic diagrams of dielectric unit cell. (a) 3D view; (b) top view

Fig. 2. Phase and normalized amplitude of cross-polarized transmission coefficient T_RL varying with frequency under LCP incident wave when the rotation angle φ_rot is 0°, 30°, 70°, 120°, and 180°, respectively

Fig. 3. Schematic diagram of dual-dimensional multi-channel multiplexing based on terahertz dielectric metasurface combined with OAM and frequency

Fig. 4. Schematic diagrams of phase profile and structure of dielectric metasurface. (a) Phase profile; (b) 3D view and top view

Fig. 5. Simulated far-field amplitude and phase patterns of RCP transmission waves when LCP plane waves with frequency f₁ and angle θ_i(f₁) are incident on metasurface along with -x, -y, +x, and +y directions, respectively. (a) Channel C₁₁; (b) channel C₂₁; (c) channel C₃₁; (d) channel C₄₁

Fig. 6. Simulated far-field amplitude and phase patterns of RCP transmission waves when LCP plane waves with frequency f₂ and angle θ_i(f₂) are incident on metasurface along with -x, -y, +x, and +y directions, respectively. (a) Channel C₁₂; (b) channel C₂₂; (c) channel C₃₂; (d) channel C₄₂

Fig. 7. Simulated far-field amplitude and phase patterns of RCP transmission waves when LCP plane waves with frequency f₃ and angle θ_i(f₃) are incident on metasurface along with -x, -y, +x, and +y directions, respectively. (a) Channel C₁₃; (b) channel C₂₃; (c) channel C₃₃; (d) channel C₄₃

Fig. 8. For channel C₁₁, when LCP plane wave with frequency f₁ and angle θ_i(f₁) is incident on metasurface along with -x direction, that is (-18.3°, 0°), simulated far-field result of RCP transmission wave, and amplitude and phase results in directions of (-18.3°, 18.3°), (-36.6°, 0°), and (-18.3°, -18.3°)