Multi‐Dimensional Optical Encryption With Metasurface‐Enabled Perfect Vortex Beam Array

Abstract

Perfect vortex beams (PVBs) carry valuable information in the intensity, phase, and polarization dimensions, offering powerful tools for optical communication, particle manipulation, and information encryption. Combining PVBs with a metasurface platform opens an avenue for multidimensional, high‐capacity, and secure optical encryption. However, precise control of the encoded dimensions and channels remains challenging. Here, we propose an optical encryption strategy based on a metasurface‐generated PVB array with four independent encryption dimensions and 441 parallel spatial channels. These dimensions, including PVB diameter, topological charge (TC) magnitude, TC sign, and polarization state, are mutually independent, significantly increasing the information capacity. In particular, the two phase‐related dimensions enhance encryption security because they cannot be directly measured by conventional CCDs. As a proof of concept, we develop a metasurface encryption system with high information capacity and improved security in the terahertz band. Four different QR codes are encrypted in a single metasurface device and can be decrypted only with the correct keys. By using each PVB as a basic information unit, the system becomes more controllable and robust. This work provides a strategy for high‐capacity and secure optical encryption, paving the way toward multidimensional photonic devices for encryption, data storage, and optical communication.