An Adaptive Parameter Control Scheme of Core Devices in DV-QKD

In a discrete-variable quantum key distribution (DV-QKD) system, the optical devices, such as the single photon detector (SPD) and optical fiber, can be affected by the external environment. This will lead to the reduction of the efficiency of QKD system. In order to reduce the impact of the changes of external environment and maintain the system efficient and stable, it is necessary to control the parameters of SPD and phase modulator (PM). In this paper, an adaptive parameter control scheme of core devices in DV-QKD system is proposed to keep the QKD system efficient and stable. The scheme has been implemented and tested in a “Plug&Play” DV-QKD system developed by our research group. The experimental results demonstrate the effectiveness of our scheme. Besides, the scheme can also be modified accordingly to suit for other types of DV-QKD systems.