Practical 15 Mb/s quantum key distribution using compact single-photon detectors

Quantum key distribution (QKD) is recognized as an unconditionally secure method of communication encryption, relying solely on the principles of quantum mechanics. A key performance metric for a QKD system is secure key rate (SKR), which is a critical factor for real-world applications. Herein, we report a practical QKD system, equipped with compact gated InGaAs/InP single-photon detectors (SPDs), that has the ability to generate a high SKR of 15.2 Mb/s with a channel loss of 2 dB. This exceptional performance stems from the ultra-low afterpulsing probability of the SPDs, which significantly reduce the bit error rate in the QKD system. The typical quantum bit error rate (QBER) is 1.3%. The results validate the feasibility of an integrated, practical QKD system and offer a reliable solution for the future development of real-world QKD networks.