(a) A typical geometry of cross-shaped aperture and optical transmission images of the university logo with colors between the lettering and the background interconverted under the linear polarized direction of 0° or 90°. (b) Bright-field transmission images produced by the aperture array when back-illuminated with white light under LPL of the orthogonal polarization state. (c) Structure of the linearly polarizable V-shaped gold antenna for nonlinear holograms and two third-harmonic generation holographic images at 422 nm generated by vertically or horizontally polarized light at 1266 nm, respectively. (d) The transmission process of chiral color pixels under LCP and RCP illumination and the geometric structure of double-layer aluminum arcs. (e) Methods to encode two different images into one color print by designing the structure of pixels in one piece. (f) Information encryption and recognition processes of paper-printed QR codes covered by self-healing chiral photonic films. (g) Cloverleaf images composed of stratified chiral photonic polymers displayed under different polarization light. (h) Three design principles and the corresponding images of the single-celled trifunctional metasurface with triple manipulations of light. (i) Approaches of information encryption based on the metasurface with an independent channel of wavelength and polarization and its corresponding pattern presented under different input conditions. Reproduced with permissions: (a) from [92
], Copyright 2016, American Chemical Society; (d, e) from [95
], Copyright 2019, The Royal Society of Chemistry; (f) from [98
], Copyright 2018, The Royal Society of Chemistry; (g) from [99
], Copyright 2019, Wiley-VCH; (h) from [100
], Copyright 2020, Wiley-VCH; (i) from [102
], Copyright 2019, American Chemical Society.