Measurement of microwave meta-quaternion vortex arrays enabling Luoshu-WeightLock imaging encryption

Electromagnetic metasurfaces exhibit considerable potential for generating high-purity vortex beams and enabling high-resolution imaging and information encryption. However, traditional GHz devices face challenges, including reduced efficiency due to bulky size and material losses. Herein, we designed a multilayer structure and demonstrated through simulations that this configuration served as an efficient transmissive meta-atom. We designed arrays in multiple sizes and finally determined that the optimal minimal unit was the meta-quaternion vortex array, which was subsequently used as the pixel basis for the target image. A digitally patterned GHz metadevice was fabricated and experimentally characterized with right-handed circularly polarized (RCP) light. The experimental results were in excellent agreement with the simulations. We combined the classical nine-grid encryption method (Luoshu) with metasurfaces and introduced the weighted superposition computation technique (WeightLock) to achieve multilayer encryption of target characters. Our research offered novel strategies for the next-generation 5G/6G communication systems, radar detection, and information encryption fields, demonstrating broad application prospects in intelligent communication and advanced radar technologies.