High-fidelity multiplexing meta-hologram for information display, storage and encryption. (December 2022)

• Record Type: Journal Article
• Authors: Liu, Tonghao; Li, Weihan; Meng, Yueyu; Tang, Wenxuan; Ma, Hua; Li, Xiaofeng; Zhu, Ruichao; Liu, Chao; Zhang, Hong; Wang, Jiafu; Qu, Shaobo
• Is Part Of: Materials & design. Volume 224(2022)
• Publication Date: 2022-12
• Subjects: Holography -- Multiplexing meta-holograms -- Information encryption -- High fidelity -- Circular polarizations -- Geometric phase; Materials -- Periodicals; Engineering design -- Periodicals; Matériaux -- Périodiques; Conception technique -- Périodiques; Electronic journals; 620.11
• DOI: 10.1016/j.matdes.2022.111353
• Languages: English
• ISSNs: 0264-1275

Abstract

Graphical abstract: Highlights: The Rayleigh-Sommerfeld diffraction theory and the diffractive neural network algorithm are used to construct the multiplexing meta-hologram. Low channel crosstalk of the designed helicity-assisted meta-atom ensures the high fidelity of the reconstructed multiple images. The multiplexing meta-hologram is proposed to independently and simultaneously reconstruct four images in three amplitude-phase channels and one phase-only channel. The multiplexing meta-hologram can theoretically achieve perfect holography in sixteen imaging channels by easily rotating, mirroring, and arranging the structures. The multiplexing meta-hologram is able to realize information display, storage and encryption by encoding all imaging channels. Abstract: Holography has been continuously spurring tremendous interest of researchers attributed to its unparalleled capability of photographically reconstructing the desired images. Based on the metasurfaces with multiple degrees of freedom, multiplexing meta-holograms are experiencing the research upsurge because of enormous application potential. However, existing multiplexing meta-holograms cannot tailor the amplitude information, and possess limited imaging channels and high channel crosstalk, which hinder the improvement of information capacity and imaging quality of multiplexing meta-holograms. Herein, an innovative multiplexing meta-hologram based on the helicity-assisted meta-atoms is proposed, which can perfectly reconstruct four independent images by altering the working frequency, polarization state and propagation direction of incident waves, and theoretically realize the holography in sixteen different channels by easily rotating, mirroring, and arranging the structures of meta-atoms. Numerous simulations and experiments collectively corroborate the feasibility of our methodology, and the quantitative analyses verify the high fidelity of the reconstructed images, which results from the low crosstalk between the amplitude modulation and phase modulation in different imaging channels. This inspiring strategy of multiplexing meta-hologram with large channel capacity and high imaging quality will have promising application prospects in information display, storage and encryption, and provide an alternative path for the design of multifunctional microwave devices.