Dual-information and large-scale structural color patterns by laser direct writing with a low-index tailored nanostructure array

Dielectric nanostructures are widely embraced in the field of structural color design due to their low-cost characteristics, enabling sub-micron scale color printing. However, challenges still exist in the selection of structures and image encryption. In this study, we propose a method for printing dual patterns using tailored scattering structures based on two-photon polymerization. We extensively analyze the color performance of each structure in zeroth-order diffraction under cross-polarized transmission and bright-field transmission illumination. By selecting appropriate structures based on their characteristics, we prepared full-color panels and successfully utilized these panels to print both color patterns and dual patterns, achieving multi-level control of color and information. Based on the above study, a large-sale color pattern with a hidden message in an area of 3.2 cm ×2.4 cm is printed, which can be directly observed. Our results demonstrate a sustainable and eco-friendly approach to color preparation, offering innovative strategies and methods for the fields of color science and steganography for information security.