Fabrication of color code by femtosecond laser-induced nanostructures on the surface of metal films with yttria-stabilized zirconia substrate

This study reported on the fabrication of color code with high capacity by femtosecond laser-induced periodic surface structures (LIPSS) on the surface of metal films with yttria-stabilized zirconia (YSZ) substrate. To solve the problem that the high-spatial-frequency LIPSS (HSFL) could not produce structural colors due to the self-organization mechanism, the method of coating metal films on the surface of YSZ was proposed. Then the low-spatial-frequency LIPSS (LSFL) which could produce structural colors were obtained by inducing the metal films. Through the organic combination of ultrafast laser oxidation and etching, uniform and complete nanostructures were obtained on the surface of Au/Ti film, in which the combination of gold nanoparticles and titanium dioxide ensured the high consistency of the fabrication of the nanostructures. The color code was prepared and displayed by adjusting the laser polarization direction and the incident angle of the light source. Finally, the decoding of color code was realized through the conversion of different base numbers. This study provided a new idea to realize the preparation and display of color code on the surface of metal films with YSZ substrate.