Fig. 1. Schematic of the anomalous reflection on metasurface with three diffraction orders

Fig. 2. (a) Schematic of unit cell of dielectric grating; (b) Dielectric metasurface for anomalous reflection

Fig. 3. Reflectivity and phase response verses the duty ratio of metagrating at 0.96 THz

Fig. 4. (a) Simulation results of anomalous reflection efficiency; (b) Electric field of anomalous reflection above the metasurface （X-Z plane）; (c) Power flow around the metasurface; (d) Anomalous reflection efficiency when the duty ratio of the first grating is scanned

Fig. 5. (a) Schematic of polarization-independent two dimensional metasurface; (b) Electric field of anomalous reflection above the two dimensional metasurface (X-Z plane); (c) Efficiency of TE mode and TM mode; (d) Anomalous reflection efficiency comparison between our design (blue) and the generalized Snell's law-based linear phase gradient profile design (red)

Fig. 6. (a) Electric field anomalous reflection above the metasurface when incident angle is 5°; (b) Anomalous reflection efficiency comparison between our design (blue) and the generalized Snell's law-based linear phase gradient profile design (red) when incident angle changes from 0° to 20°