A displacement-encoded metasurface vector holographic element for novel anti-counterfeiting technology

Abstract

The invention discloses a displacement coding type metasurface vector holographic element capable of realizing a novel anti-counterfeit technology. The metasurface vector holographic element comprisesultra-structure molecular structures of two mutually-perpendicular metal nanorods forming a metasurface; polarization selective diffraction efficiency enhancement effect generated by a metal-medium-metal sandwich structure is achieved; a linear modulation mode of a polarization state phase through local displacement between the two perpendicular metal nanorods in each ultra-structure molecule, alinear modulation mode of a wave-front total phase through global displacement between adjacent ultra-structure molecules and a linear modulation mode of a polarization state amplitude proportion through rotating angles of the metal nanorods are realized. The displacement coding type metasurface vector holographic element has advantages of low preparation control accuracy requirement, simple structure, wide incidence angle, wide operating frequency band, freeness of dispersion and the like, regulation of wavefront in any forms of phases and polarization state spatial distribution can be realized, and the security level of holographic anti-counterfeit and encryption technologies is raised greatly.

Description

technical field [0001] The invention relates to the field of holographic anti-counterfeiting technology, in particular to a displacement-coded metasurface vector holographic element capable of realizing a novel anti-counterfeiting technology. Background technique [0002] Holography is a technique for reproducing images that are realistic to the original object by recording the amplitude and phase of specific light waves and reproducing them under certain conditions. It has important applications in the field of anti-counterfeiting, such as packaging and printing anti-counterfeiting technology. There is huge room for development. In traditional holographic implementations, holographic dry plates and spatial light modulators are the most widely used optoelectronic components for holographic projection displays, but single-chip holographic dry plates or spatial light modulators can only separate Modulation, while the simultaneous modulation of the two requires cascading of mul...

AI Technical Summary

Problems solved by technology

The regulation of the phase and polarization of this superstructure unit depends on the change of the structural geometry, which requires high control accuracy and increases the difficulty of nanofabrication, which is not conducive to practical applications and large-scale mass production of devices.

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