INTEGRATED PHOTONIC CHIPS FOR QUANTUM KEY DISTRIBUTION IN SECURE OPTICAL NETWORKS

Quantum key distribution (QKD) provides information-theoretically secure communication guaranteed by the laws of quantum mechanics, offering protection against both classical and future quantum computer attacks. However, traditional bulk-optic QKD systems suffer from large size, high cost, poor scalability, and limited integration with existing fiber infrastructure. Integrated photonic chips have emerged as the key enabling technology to overcome these barriers by miniaturizing all critical components — lasers, modulators, interferometers, detectors, and frequency combs — onto millimeter-scale chips compatible with mass manufacturing.

This paper reviews the latest breakthroughs in integrated photonic QKD and presents two state-of-the-art implementations.