Hybrid intelligent strategy driving high-dimensional encrypted orbital angular momentum comb multicasting towards optical data-transmission networks.

Abstract

Achieving higher degrees and dimensions of light is one of the accessible paths for increasing the capacity of optical data-transmission systems. Orbital angular momentum (OAM), owing to its infinite and mutually orthogonal nature, offers a promising carrier for high-capacity and high-dimensional data transmission. However, current OAM-based shift keying and multicasting schemes predominantly rely on single-mode encoding or simple mode complexing, which fails to fully exploit the high-dimensional potential of OAM. This limitation primarily arises from the challenge of directly modulating complex multiplexed OAM states-such as OAM combs-which typically requires bulky optical setups and complicated iteration algorithms. Here, a hybrid intelligent strategy for high-dimensional OAM comb multicasting is demonstrated, enabling simultaneous multi-channel transmission with high-dimensional OAM encoding using a single phase-only hologram. By jointly AI-driven OAM comb generation and physics-guided wave-vector manipulation, a phase-only modulation framework is developed to directly tailor multiple structured OAM combs in a single modulation step, significantly improving the photon efficiency of OAM shift keying. The scalability and fidelity of the proposed approach are experimentally validated through 4, 6, and 8-channel multicasting demonstrations. Furthermore, a mixed encoding protocol is introduced to enhance transmission security in one-to-many multicasting scenarios, enabling parallel delivery of distinct image contents to different users. A six-channel OAM comb communication system achieves real-time transmission with a bit-error rate below 7 × 10⁻⁵. Our proposal offers a compact and scalable solution for high-dimensional OAM-based data transmission and provides a promising pathway toward next-generation large-capacity optical networks.