Single-sized phase-change metasurfaces for dynamic information multiplexing and encryption

TL;DR

This paper introduces a phase-change metasurface that enables dynamic multiplexing and encryption of near-field optical information through polarization control and reversible state switching of Sb$_2$S$_3$ meta-atoms.

Contribution

It presents a novel design of phase-change metasurfaces using orientation degeneracy and polarization control for secure, high-density optical information encoding and dynamic display.

Findings

Multiple images can be multiplexed and switched via polarization control.

Reversible switching between amorphous and crystalline states enables dynamic encryption.

High information density and security in ultra-compact metasurface design.

Abstract

Optical metasurfaces empower us to manipulate the electromagnetic space and control light propagation at the nanoscale, offering a powerful tool to achieve modulation of light for information processing and storage. In this work, we propose a phase-change metasurface to realize dynamic multiplexing and encryption of near-field information. Based on the orientation degeneracy and polarization control governed by Malus's law, we elaborately design the orientation distribution of Sb$_2$S$_3$ meta-atoms with the same dimension to simultaneously satisfy the amplitude modulation requirements of different channels. Using the corresponding polarization control as decoding keys, three different nanoprinting images can be displayed, and these multiplexed images can be switched on and off by leveraging the reversible tunability of the Sb$_2$S$_3$ meta-atoms between the amorphous and crystalline states. With the unparalleled advantages of ultra-compactness, simple design strategy, high information density and security, the proposed metasurfaces afford promising prospects for high-end applications in ultracompact and intelligent dynamic display, high-dense optical data storage, optical information encryption, etc.