Single-sized Phase-Change Metasurfaces for Dynamic Information Multiplexing and Encryption

Optical metasurfaces empower us to manipulate the electromagnetic space andcontrol light propagation at the nanoscale, offering a powerful tool to achievemodulation of light for information processing and storage. In this work, wepropose a phase-change metasurface to realize dynamic multiplexing andencryption of near-field information. Based on the orientation degeneracy andpolarization control governed by Malus's law, we elaborately design theorientation distribution of Sb_2S_3 meta-atoms with the same dimension tosimultaneously satisfy the amplitude modulation requirements of differentchannels. Using the corresponding polarization control as decoding keys, threedifferent nanoprinting images can be displayed, and these multiplexed imagescan be switched on and off by leveraging the reversible tunability of theSb_2S_3 meta-atoms between the amorphous and crystalline states. With theunparalleled advantages of ultra-compactness, simple design strategy, highinformation density and security, the proposed metasurfaces afford promisingprospects for high-end applications in ultracompact and intelligent dynamicdisplay, high-dense optical data storage, optical information encryption, etc.