Metasurface image anti-counterfeiting method based on space-frequency multiplexing

Abstract

The invention discloses a metasurface image anti-counterfeiting method based on space-frequency multiplexing, the image anti-counterfeiting method is realized by a metasurface with a polaroid function, the metasurface is composed of a substrate and a nano brick array etched on the substrate, the polarization direction and intensity of incident linearly polarized light can be regulated and controlled, and continuous gray level image display is realized. Through ingenious design of the spatial frequency, the same metasurface displays two different images under two different cut-off frequencies,and has the advantages of high resolution and high fidelity. The invention provides a novel image anti-counterfeiting method which can be widely applied to the fields of information multiplexing, encrypted display and the like.

Description

technical field [0001] The invention belongs to the field of micro-nano optics technology, and in particular relates to a metasurface image anti-counterfeiting method based on space-frequency multiplexing. Background technique [0002] Due to the increasingly sophisticated imitation technology and means, in order to protect the interests of corporate brands and consumers, anti-counterfeiting technology is becoming more and more important. In order to achieve the purpose of anti-counterfeiting, anti-counterfeiting technology needs to be able to accurately identify the authenticity and not be easily imitated. In recent years, metasurfaces have attracted much attention due to their ultrathin subwavelength structures and the advantages of precise manipulation of electromagnetic field amplitude, phase, and polarization state. As a two-dimensional planar material, metasurfaces can achieve many functions by combining some control methods. For example, metasurface holograms with di...

AI Technical Summary

Problems solved by technology

At present, many researchers use metasurface materials to control the polarization state to achieve some specific functions, but the design based on metasurface nanoprinting and superimposed spatial frequency multiplexing has not yet been proposed and studied.

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