Quantum and classic converged communication system based on MDM-SDM and transmission method

Abstract

The invention discloses a quantum and classic converged communication system based on MDM-SDM, which comprises an Alice sending end, a Bob receiving end and an MDM-SDM multiplexing unit, the Alice sending end is connected with the Bob receiving end through the MDM-SDM multiplexing unit. According to the invention, the heterogeneous groove-assisted gradient refractive index type FM-MCF special optical fiber is adopted, an MDM-SDM two-dimensional multiplexing quantum and classic fusion transmission system is realized, and the capacity bottleneck of a fusion network is solved. By selecting the appropriate number of fiber cores and the appropriate number of modes, the requirement for signal processing can be lowered, interference of classic signals on quantum signals is further reduced throughmode orthogonality and spatial isolation between the signals, and better quantum key distribution performance can be easily obtained during converged communication. And a feasible scheme with high security, low loss and low cost is provided for the construction of a super-large capacity converged communication network in the future.

Description

technical field [0001] The invention relates to the field of quantum information, in particular to an MDM-SDM-based quantum and classical fusion communication system and transmission method. Background technique [0002] Quantum secure communication provides the potential of secure key distribution under the guarantee of quantum mechanics, and proves the possibility of unconditional security. It is the fastest-growing, most practical and scalable technology in quantum communication. In the past 30 years, free space and optical fiber-based QKD (Quantum Key Distribution, Quantum Key Distribution) experiments have proved the feasibility of quantum secure communication by using different physical principles. However, QKD systems generally use dedicated optical fibers and equipment, which has limitations in network scale and practicability. In order to reduce costs and increase the efficiency of optical fiber transmission, QKD and classical communication systems can be integrate...

AI Technical Summary

Problems solved by technology

In 2019, Tobias A. Eriksson et al. experimentally studied the feasibility of space division multiplexing of CV-QKD signals and WDM multiplexed 24.5Gbaud 16QAM (Quadrature Amplitude Modulation, quadrature amplitude modulation) in 19-core MCF. Placing the CV-QKD signal at the wavelength in the guard band of the classic signal band further suppresses the crosstalk between signals, but because of the limited cladding space of the multi-core fiber used, the number of cores is limited, which is not conducive to further Increase transmission capacity

[0005] "Existing technology patent: (CN110247705A) provides a quantum access network architecture and method based on multi-core optical fiber, which can support a large number of quantum user access, but the seven-core optical fiber used in it has limited cladding, and it is difficult to further increase communication capacity. , the present invention better proposes to use FM-MCF special optical fiber to realize converged transmission, and utilizes the two-dimensional multiplexing method combining space dimension and mode dimension to solve the communication capacity bottleneck problem

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