中国物理B ›› 2023, Vol. 32 ›› Issue (3): 30306-030306.doi: 10.1088/1674-1056/ac7450

• • 上一篇    下一篇

Performance analysis of quantum key distribution using polarized coherent-states in free-space channel

Zengte Zheng(郑增特)1, Ziyang Chen(陈子扬)2,†, Luyu Huang(黄露雨)1, Xiangyu Wang(王翔宇)1,‡, and Song Yu(喻松)1   

  1. 1 State Key Laboratory of Information Photonics and Optical Communications, Beijing University of Posts and Telecommunications, Beijing 100876, China;
    2 State Key Laboratory of Advanced Optical Communication Systems and Networks, School of Electronics, and Center for Quantum Information Technology, Peking University, Beijing 100871, China
  • 收稿日期:2022-03-18 修回日期:2022-05-09 接受日期:2022-05-29 出版日期:2023-02-14 发布日期:2023-02-21
  • 通讯作者: Ziyang Chen, Xiangyu Wang E-mail:chenziyang@pku.edu.cn;xywang@bupt.edu.cn
  • 基金资助:
    This work was supported by the Key Program of the National Natural Science Foundation of China (Grant No. 61531003), the National Natural Science Foundation of China (Grant No. 62001041), China Postdoctoral Science Foundation (Grant No. 2020TQ0016), and the Fund of State Key Laboratory of Information Photonics and Optical Communications.

Performance analysis of quantum key distribution using polarized coherent-states in free-space channel

Zengte Zheng(郑增特)1, Ziyang Chen(陈子扬)2,†, Luyu Huang(黄露雨)1, Xiangyu Wang(王翔宇)1,‡, and Song Yu(喻松)1   

  1. 1 State Key Laboratory of Information Photonics and Optical Communications, Beijing University of Posts and Telecommunications, Beijing 100876, China;
    2 State Key Laboratory of Advanced Optical Communication Systems and Networks, School of Electronics, and Center for Quantum Information Technology, Peking University, Beijing 100871, China
  • Received:2022-03-18 Revised:2022-05-09 Accepted:2022-05-29 Online:2023-02-14 Published:2023-02-21
  • Contact: Ziyang Chen, Xiangyu Wang E-mail:chenziyang@pku.edu.cn;xywang@bupt.edu.cn
  • Supported by:
    This work was supported by the Key Program of the National Natural Science Foundation of China (Grant No. 61531003), the National Natural Science Foundation of China (Grant No. 62001041), China Postdoctoral Science Foundation (Grant No. 2020TQ0016), and the Fund of State Key Laboratory of Information Photonics and Optical Communications.

摘要: In free space channel, continuous-variable quantum key distribution (CV-QKD) using polarized coherent-states can not only make the signal state more stable and less susceptible to interference based on the polarization non-sensitive of the free-space channel, but also reduce the noise introduced by phase interference. However, arbitrary continuous modulation can not be carried out in the past polarization coding, resulting in that the signal state can not obtain arbitrary continuous value in Poincare space, and the security analysis of CV-QKD using polarized coherent-states in free space is not complete. Here we propose a new modulation method to extend the modulation range of signal states with an optical-fiber-based polarization controller. In particular, in terms of the main influence factors in the free-space channel, we utilize the beam extinction and elliptical model when considering the transmittance and adopt the formulation of secret key rate. In addition, the performance of the proposed scheme under foggy weather is also taken into consideration to reveal the influence of severe weather. Numerical simulation shows that the proposed scheme is seriously affected by attenuation under foggy weather. The protocol fails when visibility is less than 1 km. At the same time, the wavelength can affect the performance of the proposed scheme. Specifically, under foggy weather, the longer the wavelength, the smaller the attenuation coefficient, and the better the transmission performance. Our proposed scheme can expand the modulation range of signal state, and supplement the security research of the scheme in the free-space channel, thus can provide theoretical support for subsequent experiments.

关键词: polarized coherent-states, free-space channel, performance analysis

Abstract: In free space channel, continuous-variable quantum key distribution (CV-QKD) using polarized coherent-states can not only make the signal state more stable and less susceptible to interference based on the polarization non-sensitive of the free-space channel, but also reduce the noise introduced by phase interference. However, arbitrary continuous modulation can not be carried out in the past polarization coding, resulting in that the signal state can not obtain arbitrary continuous value in Poincare space, and the security analysis of CV-QKD using polarized coherent-states in free space is not complete. Here we propose a new modulation method to extend the modulation range of signal states with an optical-fiber-based polarization controller. In particular, in terms of the main influence factors in the free-space channel, we utilize the beam extinction and elliptical model when considering the transmittance and adopt the formulation of secret key rate. In addition, the performance of the proposed scheme under foggy weather is also taken into consideration to reveal the influence of severe weather. Numerical simulation shows that the proposed scheme is seriously affected by attenuation under foggy weather. The protocol fails when visibility is less than 1 km. At the same time, the wavelength can affect the performance of the proposed scheme. Specifically, under foggy weather, the longer the wavelength, the smaller the attenuation coefficient, and the better the transmission performance. Our proposed scheme can expand the modulation range of signal state, and supplement the security research of the scheme in the free-space channel, thus can provide theoretical support for subsequent experiments.

Key words: polarized coherent-states, free-space channel, performance analysis

中图分类号:  (Quantum cryptography and communication security)

  • 03.67.Dd
03.67.Hk (Quantum communication) 03.67.-a (Quantum information)