Modeling Optical Fiber Space Division Multiplexed Quantum Key Distribution Systems

We report a model to evaluate the performance of multiple quantum key distribution (QKD) channel transmission using spatial division multiplexing (SDM) in multicore (MCF) and few-mode fibers (FMF). The model is then used to analyze the feasibility of QKD transmission in 7-core MCFs for two scenarios of practical interest. First for transmission of only QKD channels, the second for simultaneous transmission of QKD and classical channels. In the first case, standard homogeneous MCFs enable transmission distances per core compatible with transmission parameters (distance and net key rate) very close to those of single core singlemode fibers. For the second case, heterogeneous MCFs must be employed to make this option feasible