一种用于实际高速量子密钥分发的5GHz和7.5V多幅度调制器驱动电路。

A 5 GHz and 7.5 V multi-amplitude modulator driving circuit for practical high-speed quantum key distribution.

作者信息

Liu Xiang, Huang Ming-Qi, Min Hao, Jin Ge, Jiang Xiao, Peng Cheng-Zhi

机构信息

Hefei National Laboratory for Physical Sciences at the Microscale and Department of Modern Physics, University of Science and Technology of China, Hefei, Anhui 230026, China.

CAS Center for Excellence and Synergetic Innovation Center in Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei, Anhui 230026, China.

出版信息

Rev Sci Instrum. 2020 Feb 1;91(2):024705. doi: 10.1063/1.5140695.

DOI:10.1063/1.5140695

PMID:32113405

Abstract

Quantum key distribution (QKD) offers the ability of information theoretic security key exchange. The secure key rate is an important indicator for the practical QKD systems, which determines what kinds of applications can be supported. One most effective way to enhance the secure key rate is to increase the system repetition frequency. Here, we report an implementation of a high-speed DC-coupled modulator driving circuit with a repetition rate of up to 5 GHz. The circuit outputs a multi-amplitude return-to-zero pattern pulse with a maximum amplitude of 7.5 V. The design adapts to the various electro-optic modulators widely employed in QKD systems. The minimum pulse width is measured as 75 ps, with the relative noise level less than 1.5% for all the output amplitudes under random modulation.

摘要

量子密钥分发（QKD）提供了信息理论安全密钥交换的能力。安全密钥率是实际QKD系统的一个重要指标，它决定了可以支持哪些类型的应用。提高安全密钥率的一种最有效方法是提高系统重复频率。在此，我们报告了一种重复率高达5 GHz的高速直流耦合调制器驱动电路的实现。该电路输出最大幅度为7.5 V的多幅度归零型脉冲。该设计适用于QKD系统中广泛使用的各种电光调制器。测量得到的最小脉冲宽度为75 ps，在随机调制下，所有输出幅度的相对噪声水平均小于1.5%。