Photonic integrated quantum key distribution receiver for multiple users

Abstract

Integrated photonics has the advantages of miniaturization, low cost, and CMOS compatibility, and it provides a stable, highly integrated, and practical platform for quantum key distribution (QKD). While photonic integration of optical components has greatly reduced the overall cost of QKD systems, single-photon detectors (SPDs) have become the most expensive part of a practical QKD system. In order to circumvent this obstacle and make full use of SPDs, we have designed and fabricated a QKD receiver chip for multiple users. Our chip is based on time-division multiplexing technique and makes use of a single set of SPDs to support up to four users QKD. Our proof-ofprinciple chip-based QKD system is capable of producing an average secret key rate of 13.68 kbps for four users with a quantum bit error rate (QBER) as low as 0.51% over a simulated distance of 20 km in fiber. Our result clearly demonstrates the feasibility of multiplexing SPDs for setting QKD channels with different users using photonic integrated chip and may find applications in the commercialization of quantum communication technology.

Chip-based quantum key distribution

“…The MDI-QKD architecture is naturally suited for multi-user QKD networks [43], since the most expensive and intricate component-the measurement device-can be placed in an untrusted relay and shared among many QKD users. Therefore, MDI-QKD has been widely recognized as a promising quantum communication technology for star-type secured networks [34,44].…”

Advances in Chip-Based Quantum Key Distribution

“…The Si-based integrated chip provided a phase-stable platform for high-speed QKD. Other qubit-based QKD demonstrations using Si-based implementations include works carried out by Huawei [ 97 ], the Toshiba Cambridge Institute [ 98 ], Sun Yat-sen University [ 99 ], the University of Padua [ 100 ], IOS-CAS [ 103 , 105 ] and the University of Science and Technology of China [ 104 , 105 ].…”

Advances in Silicon Quantum Photonics

“…SNSPDs are among the most costly and least portable resource in quantum photonicstheir availability is often a bottleneck in quantum photonics research. Time multiplexing detectors between multiple users alleviates this, and was recently demonstrated in a QKD setting with a silicon chip [293].…”