Multiscale Chiral Plasmonic Structural Color Metamaterials With Tunable Chirality and Polarization‐Dependent Optical Encryption

ABSTRACT Chiral plasmonic structural color metamaterials (CPCMs), composed of two Ag/Au nanoshells and nanoholes with intermediate polystyrene spheres, are fabricated via a single etching and two deposition steps. The resulting heterostructures simultaneously generate plasmonic colors and strong chiroptical activity in the visible region, with the g ‐factor up to 0.16. The color originates from the coupling between the Ag/Au nanoshells and nanoholes, while the chirality stems from the asymmetric electric field distribution and current oscillations. Both color and chirality can be precisely tuned by adjusting the feature size and the overlap angle between metal layers. Due to the anisotropic geometry of the CPCMs, polarization‐controllable color changes are observed. Furthermore, combination with projection micro‐stereolithography (PµSL) enables multiscale patterning of left‐ and right‐ CPCMs on a single substrate, allowing polarization‐dependent optical encryption. This scalable platform provides a versatile route toward programmable chiroptical devices, sensing, and anti‐counterfeiting applications.