Intercore spontaneous Raman scattering impact on quantum key distribution in multicore fiber

Abstract

We propose a theoretical model to quantitatively estimate the intercore spontaneous Raman scattering (ICSRS) in multicore fiber based on intercore crosstalk. We analyze the properties of ICSRS through numerical simulations. Then, the impact of ICSRS on quantum key distribution (QKD) is evaluated with a classical dense wavelength division multiplexing system in a seven-core fiber. We evaluate the impact in two scenarios, long-distance transmission and metropolitan area transmission. For long-distance transmission, it is revealed that both the forward-ICSRS and backward-ICSRS will reduce the maximum transmission distance of QKD and backward-ICSRS has more impairment to QKD. However, over the range of metropolitan area networks, QKD is not impaired seriously by ICSRS with typical power of classical signal. Finally, we compare the properties of SRS generated in single-core fiber and the properties of ICSRS.