Theoretical analysis of quantum key distribution systems when integrated with a DWDM optical transport network

TL;DR

This paper provides a theoretical and numerical analysis of how noise from Raman scattering, four-wave mixing, and crosstalk affects various quantum key distribution systems integrated with classical DWDM networks, focusing on secure key rates and maximum distances.

Contribution

It offers a comprehensive theoretical framework and simulation results for the performance of different QKD protocols within DWDM networks, considering various channel configurations.

Findings

Optimal configurations maximize achievable distance.

Secure key rates depend on channel allocation schemes.

Performance varies between C-band and O-band implementations.

Abstract

A theoretical research and numerical simulation of the noise influence caused by spontaneous Raman scattering, four-wave mixing, and linear channel crosstalk on the performance of QKD systems was conducted. Three types of QKD systems were considered: coherent one-way (COW) QKD protocol, subcarrier-wave (SCW) QKD system, and continuous-variable (CV) QKD integrated with classical DWDM channels. We calculate the secure key generation rate for the systems mentioned addressing different channel allocation schemes (i.e., configurations). A uniform DWDM grid is considered with quantum channel located in C-band and O-band (at 1310 nm) of a telecommunication window. The systems' performance is analyzed in terms of the maximal achievable distance values. Configurations for the further analysis and investigation are chosen optimally, i.e., their maximal achievable distances are the best.