Cascaded metasurface for separated information encryption [Invited]
Jiahao Wang, Guodong Zhu, Weiguo Zhang, Zhou Zhou, Zile Li, Guoxing Zheng
Abstract
For a conventional cascaded metasurface, the combination channel and each single channel are mutually dependent because the phase modulation of a cascaded metasurface is the sum of each single one. Here we propose a cascaded metasurface that can independently encode information into multiple channels. Based on the orientation degeneracy of anisotropic metasurfaces, each single metasurface can produce a quick-response (QR) image in the near field, governed by the Malus law, while the combined channel can produce a holographic image in the far field, governed by geometric phase. The independent and physically separated trichannel design makes information encryption safer.