A spin and intensity multiplexed encryption metasurface

Recently, metasurfaces have received widespread attention due to their superior performance in regulating the physical properties of light. In the field of optical encryption, the most common methods utilizing metasurfaces mainly include metasurface coloration, malus metasurfaces and metasurface holography. However, such methods are complex to achieve and prone to noise interference. Here, a spin and intensity multiplexed compact metasurface optical element is proposed and its feasibility for stable optical encryption is verified through simulations. Based on the photon spin Hall effect, a series of optical ciphertexts are generated with continuous changes in the spin state and intensity. As a concept demonstration, this spin and intensity multiplexed encryption metasurface will promote advanced applications of metasurfaces in many fields, such as optical communication and holography.