Fig. 1. Unit structure of metasurface for light field regulation. (a) Schematic of the unit cell of the metasurface structure for achieving broadband linear-circular polarization conversion^[1]; (b) schematic of silicon metasurface with huge intrinsic chirality^[2]; (c) resonant superstructure surface^[3]; (d) experimental image obtained on a plane 10 mm above the metasurface hologram^[4]; (e) schematic of complementary V-shaped antenna, simulating cross polarized radiation scattering amplitude and phase of a single complementary V-shaped antenna on a 500-μm thick silicon substrate^[5]; (f) structure of encoded particles^[6]; (g) schematic of pure phase space terahertz modulator^[7]

Fig. 2. Flowchart of computed generated hologram

Fig. 3. Flowchart of GS algorithm

Fig. 4. Experimental results of GS algorithm^[13]. (a) Ideal amplitude distribution in the target character plane; (b) ideal phase distribution; (c) experimental amplitude distribution; (d) experimental phase distribution

Fig. 5. Different images presented under left and right circularly polarized light, respectively^[14]

Fig. 6. Holographic images generated by left circularly polarized light incident on an asymmetric transmission type metasurface^[11]. (a) Incident from the front; (b) incident from the back; (c) simulated diffraction results

Fig. 7. Imaging effects of metasurface transmission space and transmission space under different polarized light irradiation^[16]

Fig. 8. Simulation result^[19]

Fig. 9. Flowchart of Yang-Gu algorithm^[22]

Fig. 10. Sampling images taken with different focal lengths and experimental results^[24]. (a) Photo taken at a focal length of 18 mm; (b) photo taken at a 55-mm focal length; (c) phase recovery diagram of Fig.10(a); (d) phase recovery diagram of Fig.10(b); (e) reconstruction of images

Fig. 11. Schematic of point source method^[25]

Fig. 12. Simulation results of image reconstruction at 10 GHz and 13 GHz^[21]. (a) Electric field distribution of the x-polarized component at the preset imaging plane at 10 GHz; (b) electric field distribution of the y-polarized component at the preset imaging plane at 10 GHz; (c) electric field distribution of the x-polarized component at the preset imaging plane at 13 GHz; (d) electric field distribution of y-polarized component at the preset imaging plane at 13 GHz

Fig. 13. Flowchart of simulated annealing algorithm

Fig. 14. Comparison between the calculated expected image and experimental result^[26]

Fig. 15. Comparison between theoretical calculation results and experimental results^[7]. (a) (d) Letter"C"; (b) (e) letter"N";(c) (f) letter"U"

Fig. 16. Simulation results^[28]. (a) Image of the letter"H"; (b) image of the letter"I"; (c) image of the letter"T"

Fig. 17. Flowchart of genetic algorithm

Fig. 18. Image reconstruction results^[29]. (a) Binary image reconstructed by hybrid genetic algorithm; (b) reconstructed image obtained by optimizing the co-vertex positions within cells using a hybrid genetic algorithm