Panchromatic plasmonic color patterns: from embedded Ag nanohole arrays to elevated Ag nanohole arrays

Plasmonic structural color is one of the most fascinating applications of recently fast developing plasmonics, which is a promising candidate technology for information processing, color displays and optical measurement devices. However, the implementation of plasmonic structural color in modern optical and spectral imaging systems demands strongly a simple fabrication process, low power consumption, and complex color pattern integration. Thus far, tuning of the plasmonic color has been generally achieved by morphology alteration or adjusting the lattice constants of plasmonic nanostructures. Nevertheless, this strategy suffers greatly from high cost and low throughput when designing complex color patterns. Herein, by precisely controlling the refractive indices on two sides of Ag nanohole arrays (NAs) that are embedded between a silica coating and a glass substrate, we are capable of filtering white light into individual colors across the entire visible band. Moreover, the straightforward strategy we propose is compatible with the traditional photolithography process, with which complex color patterns can be easily achieved. We further experimentally demonstrate that these engineered colored samples can be used as chromatically switchable anti-counterfeit tags. We anticipate that the method we demonstrate can provide a new approach for the fabrication of compact color filtering devices.