Fig. 1. Conceptual diagram of three-wavelength holographic display and encryption for dual-structure metasurfaces

Fig. 2. Phase optimization flowchart of metasurfaces

Fig. 3. Simulation results of the nanobrick. (a) Schematic of nanostructure; (b) polarization conversion efficiency and relative propagation phase

Fig. 4. Design of the three-wavelength phase modulation scheme. (a) Optimized orientation angles and propagation phase distributions; (b) fabricated metasurfaces and partial scanning electronic microscopic image; (c) experimental setup; (d) imaging results for the three channels

Fig. 5. Encryption and simulation results of the three-wavelength channel metasurfaces scheme. (a) Encryption flowchart; (b) decryption process and results diagram

Fig. 6. Different decrypted parameters