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arXiv · 2005.09956

Polarization-Encrypted Orbital Angular Momentum Multiplexed Metasurface Holography

Hongqiang Zhou·Basudeb Sain·Yongtian Wang·Christian Schlickriede·Ruizhe Zhao·Xue Zhang·Qunshuo Wei·Xiaowei Li·Lingling Huang·Thomas Zentgraf
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Abstract

Metasurface holography has the advantage of realizing complex wavefront modulation by thin layers together with the progressive technique of computer-generated holographic imaging. Despite the well-known light parameters, like amplitude, phase, polarization and frequency, the orbital angular momentum (OAM) of a beam can be regarded as another degree of freedom. Here, we propose and demonstrate orbital angular momentum multiplexing at different polarization channels using a birefringent metasurface for holographic encryption. The OAM selective holographic information can only be reconstructed with the exact topological charge and a specific polarization state. By using an incident beam with different topological charges as erasers, we mimic a super-resolution case for the reconstructed image, in analogy to the well-known STED technique in microscopy. The combination of multiple polarization channels together with the orbital angular momentum selectivity provides a higher security level for holographic encryption. Such a technique can be applied for beam shaping, optical camouflage, data storage, and dynamic displays.

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Hongqiang Zhou, Basudeb Sain, Yongtian Wang, Christian Schlickriede, Ruizhe Zhao, Xue Zhang, Qunshuo Wei, Xiaowei Li, Lingling Huang, Thomas Zentgraf. 2020-05-20. Polarization-Encrypted Orbital Angular Momentum Multiplexed Metasurface Holography. https://doi.org/10.1021/acsnano.9b09814

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