Reference-frame-independent quantum key distribution of wavelength division multiplexing with multiple quantum channels* *Project supported by the Fundamental Research Funds for the Central Universities, China (Grant No. 2019XD-A02), the State Key Laboratory of Information Photonics and Optical Communications, Beijing University of Posts and Telecommunications (BUPT) (Grant No. IPOC2021ZT10), and BUPT Innovation and Entrepreneurship Support Program (Grant No. 2021-YC-A315).

Abstract

Reference-frame-independent quantum key distribution (RFI-QKD) can allow a quantum key distribution system to obtain the ideal key rate and transmission distance without reference system calibration, which has attracted much attention. Here, we propose an RFI-QKD protocol based on wavelength division multiplexing (WDM) considering finite-key analysis and crosstalk. The finite-key bound for RFI-QKD with decoy states is derived under the crosstalk of WDM. The resulting secret key rate of RFI-QKD, which is more rigorous, is obtained. Simulation results reveal that the secret key rate of RFI-QKD based on WDM is affected by the multiplexing channel number, as well as crosstalk between adjacent channels.