Recent Advances in Silicon Photonics for Quantum Key Distribution

Abstract

As a secure communication technology grounded in the principles of quantum mechanics, Quantum Key Distribution (QKD) holds great promise for future information security. However, the practical deployment of QKD hinges critically on system integration. Integrated optical quantum technologies offer a compact, stable, and scalable solution by enabling precise control over the generation, transmission, and detection of quantum states of light. Among the diverse photonic integration platforms, silicon photonics is particularly notable for its compatibility with Complementary Metal-Oxide-Semiconductor (CMOS) processes, its high integration density, and its potential for large-scale production. These features make silicon photonics a leading candidate for advancing QKD systems toward chip-scale realization. This review focuses on recent progress in QKD system demonstrations based on silicon photonics, highlighting the key technological milestones and integration strategies that are driving the transition from laboratory prototypes to real-world applications.

Keywords

• QKD
• integrated optical quantum technology
• silicon photonics