Reprogrammable meta-hologram for optical encryption

Abstract

Meta-holographic encryption is a potentially important technique for information security. Despite rapid progresses in multi-tasked meta-holograms, the number of information channels available in metasurfaces is limited, making meta-holographic encryption vulnerable to some attacking algorithms. Herein, we demonstrate a re-programmable metasurface that can produce arbitrary holographic images for optical encryption. The encrypted information is divided into two matrices. These two matrices are imposed to the incident light and the metasurface, respectively. While the all-dielectric metasurface is static, the phase matrix of incident light provides additional degrees of freedom to precisely control the eventual functions at will. With a single Si metasurface, arbitrary holographic images and videos have been transported and decrypted. We hope that this work paves a more promising way to optical information encryption and authentication.

Pixelated bifunctional metasurface-driven dynamic vectorial holographic color prints for photonic security platform

“…In other words, multiple pieces of information can be encoded into a single optical device. Thus, multifunctional metasurfaces not only enable miniaturized systems that can outperform existing optical devices, but they also open up applications in fields such as optical cryptography 28 – 32 or light detection and ranging (LiDAR) 20 , 21 , 33 – 35 .…”

Optical Coherence Encryption with Structured Random Light

“…Recent progress in the light field structure engineering [50][51][52], has highlighted the degrees of freedom of a structured light field as powerful tools for information encoding. For example, the optical encryption protocols based on the phase structure modulation [53] and orbital angular momentum and polarization state mode division multiplexing [54][55][56][57][58][59][60] have been developed lately.…”

Metasurface-based key for computational imaging encryption

“…Composed of two-dimensional (2D) arrays of nano-/micro-light scatterers (e.g., antennas and resonators), metasurfaces can effectively tailor different DOFs of light with their ultra-thin thicknesses (1)(2)(3)(4)(5)(6)(7)(8)(9)(10)(11)(12)(13)(14), leading to a series of potential applications in optical encryption. By modulating the polarization states and nonlinear responses in multiple channels, metasurface imaging has been used to encode and decode different images (15)(16)(17)(18)(19)(20)(21)(22)(23)(24)(25)(26)(27)(28)(29)(30)(31)(32)(33)(34). By modulating both the spectral and polarization responses, metasurface holography has been successfully applied to hiding different information into different colors and polarization channels (16)(17)(18)(19)(20)(21)(22)(23)(24)(25)(26)…”

“…By modulating the polarization states and nonlinear responses in multiple channels, metasurface imaging has been used to encode and decode different images (15)(16)(17)(18)(19)(20)(21)(22)(23)(24)(25)(26)(27)(28)(29)(30)(31)(32)(33)(34). By modulating both the spectral and polarization responses, metasurface holography has been successfully applied to hiding different information into different colors and polarization channels (16)(17)(18)(19)(20)(21)(22)(23)(24)(25)(26)(27)(28)(29). By controlling the linear polarization states for both the incident light and outgoing light, Malus metasurfaces that operate based on Malus's law have been designed and applied to multi-image encryption and anti-counterfeiting (30)(31)(32)(33)(34).…”