A Survey of OAM-Encoded High-Dimensional Quantum Key Distribution: Foundations, Experiments, and Recent Trends
For researchers in quantum communication, this survey consolidates the state of the art and identifies practical limitations of OAM-based HD-QKD.
This survey reviews OAM-encoded high-dimensional QKD, covering fundamentals, experiments, and recent trends. It highlights challenges in generation, transmission, and detection, and summarizes progress in hybrid encodings, mode sorting, adaptive optics, and various QKD frameworks.
High-dimensional quantum key distribution (HD-QKD) enhances information efficiency and noise tolerance by encoding data in large Hilbert spaces. The orbital angular momentum (OAM) of light provides a scalable basis for such encoding and supports high-dimensional photonic communication. Practical OAM-based implementations remain constrained by challenges in state generation, transmission, and detection. This survey offers a consolidated overview of OAM-encoded HD-QKD, outlining fundamental principles, representative experiments, and system-level limitations. Recent progress in hybrid encodings, mode sorting, adaptive optics, and TF, CV, MDI, and DI frameworks is summarized with emphasis on practical feasibility.