Real-time compensation of phase drift for phase-encoded quantum key distribution systems

• 来源期刊: 科学通报(英文版)
• 学科: 工学
• 年，卷（期）: 2011,（22）
• 页码范围: 2305-2311
• 页数: 7页
• 分类号: O413|TN918.1
• 语种: 中文

摘要

Phase drift is an inherent problem in phase-encoded quantum key distribution(QKD) systems.The current active phase trackingand compensation solutions cannot satisfy the requirements of a system with nonlinearity in phase modulation.This paper presents a four-phase scanning method,which is based on the quantitative analysis of the quantum bit error rate(QBER) from phasedrift and the performance requirements of phase compensation.By obtaining the four interference fringes and adjusting the codingmatrix of the system,this method automatically calculates the accurate driving voltages for the phase modulator.The implementation and experimental tests show that the proposed method can compensate phase drift caused by environmental changes and thesystem's nonlinearity,and is applicable to large-scale QKD networks.