Fig. 1. Schematic diagram of an information-encrypting metasurface. (a) The properties of GST after direct laser writing; (b) the three characteristic structures of laser direct writing GST correspond to the processing patterns; (c) the effect of the information encryption metasurface under natural light and strong light, respectively

Fig. 2. Characterization of modified grating structures. (a) Modified grating under 100× optical microscope; (b)(c) SEM image of modified grating; (d) AFM results of modified grating; (e) the graph corresponding to (d)

Fig. 3. Characterization of the dispersion properties of GST-modified gratings. (a) Relationship between polarization and modified structure; (b)−(e) modified structure under laser polarization conditions of 0°, 10°, 30°, and 40°, respectively; (f) schematic diagram of the device used to characterize the dispersion capability; (g)−(i) real shot display of RGB color; (j) the dispersion results obtained at different angles

Fig. 4. Information encryption metasurfaces for nested processing. (a) Design diagrams of three different modified structure arrangements on the device surface. (b) Photograph of the processed area under natural light conditions. (c) and (d) are optical microscopy images of the nested and background regions, respectively. (e) Pattern information decoded from different views