Sub-wavelength structure for realizing structural color and holographic double anti-counterfeiting effect

Abstract

The invention provides a sub-wavelength structure for realizing structural color and holographic double anti-counterfeiting effect. The sub-wavelength structure comprises a metal substrate, a metal sub-wavelength structure and a medium protecting layer from bottom to top, wherein the medium protecting layer is only required when the selected metal material is easy to oxidize. The sub-wavelength structure is characterized in that under the function of transmission surface plasma resonance and local surface plasma resonance excited by the metal sub-wavelength structure, the super-narrow band circular polarization conversion is realized, and the high-purity color display is realized; by rotating an anisotropy structure, the geometric phases can be introduced without change of the structural color, the holographic codes are calculated by intersection and combination, and the completely different holographic images can be obtained in a far field; by changing the cycle and size of the sub-wavelength structure, the fork circular polarization spectrum line peak wavelength can cover the whole light wave band, so as to realize the full-color display; the anti-counterfeiting technique based on the sub-wavelength structure can be used for gradually troubleshooting, the structural color is suitable for initial inspection, and the holography is suitable for final inspection. The sub-wavelength structure has the advantages that the security class is high, the imitating threshold of a main template is high, the imitating cannot be reached within shorter time, and the structure is simple.

Description

technical field

[0001] The invention relates to the technical field of wide electromagnetic wave phase regulation and frequency spectrum selection, in particular to a sub-wavelength structure that realizes double anti-counterfeiting of structural color and holography. Background technique

[0002] Structural color appears by filtering out a specific wavelength range from a broadband light source. Due to the advantages of good durability, good display and easy observation, structural color has important application value in color display, digital imaging and anti-counterfeiting technology. The current research on structural color is to generate color through the structure's selective transmission, reflection or absorption of the spectrum, resulting in structural color devices that can only use spectral intensity information, but cannot use phase information. Using computational holography, information can be encoded as a phase or amplitude distribution, which can then be dec...

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