Research on Co-propagation System Integrating Quantum Key Distribution and Classical Communication

Abstract

【Objective】Developing devices that integrate quantum technology with communication enables the coexistence of quantum signals and classical signals in single-mode fiber networks. This can effectively promote the application and popularization of Quantum Key Distribution (QKD) technology.【Methods】The paper, through the analysis of the requirements and key technologies for co-fiber transmission, proposes a method for Continuous Variable (CV)-QKD signals and classical signals to be transmitted over the same fiber in a C-band Dense Wavelength Division Multiplexing (DWDM) system. It also, for the first time, integrates the QKD system into optical communication transmission equipment.【Results】Experimental test results prove that CV-QKD can coexist with 96 classic channels in C band. Through the 67 km link with 20.5 dB attenuation, a key rate of 0.42 kbit/s can be obtained.【Conclusion】The proposed scheme has good performance in terms of quantum key rate, stability, and co-propagation compatibility. The article further analyzes and prospects quantum network application solutions, providing technical support for building an integrated quantum secure communication network.

Keywords

• QKD
• CV
• co-propagation
• DWDM
• quantum network