A Survey of OAM-Encoded High-Dimensional Quantum Key Distribution: Foundations, Experiments, and Recent Trends

TL;DR

This survey reviews the foundational principles, experimental progress, and recent trends in high-dimensional quantum key distribution using orbital angular momentum, highlighting challenges and advancements for practical implementation.

Contribution

It provides a comprehensive overview of OAM-encoded HD-QKD, summarizing recent experimental techniques, system limitations, and emerging hybrid encoding methods.

Findings

Progress in mode sorting and adaptive optics enhances practical feasibility.

Recent experiments demonstrate high-dimensional encoding robustness.

Hybrid encoding approaches improve transmission efficiency.

Abstract

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.