Integration of classical communication and quantum key distribution using frequency division multiplexing
Yunyu Shao, Ziyi Shen, Yuehan Xu, Lang Li, Zicong Tan, Xiaojuan Liao, Peng Huang, Tao Wang, Guihua Zeng · Chinese Optics Letters · 2025
Since the working conditions of classical and quantum signals are very different, how to effectively integrate classical and quantum communication networks without affecting their respective performance has become a great challenge.In this paper, we proposed a scheme to realize classical communication and continuous-variable quantum key distribution (CV-QKD) based on frequency-division multiplexing (FDM), and we verified the feasibility of simultaneously realizing CV-QKD and classical optical communication data synchronous transmission scheme under the same infrastructure.We achieved a 0 bit error rate in 50 frames and a 20 Mb/s bit rate for the classical signal and an average secret key rate of around 5.86 × 10 5 bit/s for the quantum signal through a 4 dB fiber channel.This work provides a scheme to establish a QKD channel by only reserving a small passband in the entire optical communication instead of an entire wavelength, increasing efficiency and simplifying the integration of QKD and classical communication.