Active phase compensation of quantum key distribution system

• 来源期刊: 科学通报(英文版)
• 年，卷（期）: 2008,（9）
• 页码范围: 1310-1314
• 页数: 5页
• 语种: 英文
• DOI: 10.1007/s11434-008-0023-0

摘要

Quantum key distribution (QKD) system must be robust enough in practical communication. Besides birefringence of fiber, system performance is notably affected by phase drift. The Faraday-Michelson QKD system can auto-compensate the birefringence of fiber, but phase shift is still a serious problem in its practical operation. In this paper, the major reason of phase drift and its effect on Faraday-Michel-son QKD system is analyzed and an effective active phase compensation scheme is proposed. By this means, we demonstrate a quantum key distribution system which can stably run over 37-km fiber in practical working condition with the long-time averaged quantum bit error rate of 1.59% and the stan-dard derivation of 0.46%. This result shows that the active phase compensation scheme is suitable to be used in practical QKD systems based on double asymmetric interferometers without additional de-vices and thermal controller.