Characterization of Stimulated Raman Scattering in Field-Deployed Coupled-Core Multi-Core Fibers

We report the first experimental characterization of stimulated Raman scattering (SRS) in coupled-core multi-core fibers (MCFs). The experiment was performed using field-deployed fibers, with two complementary methodologies. First, the effective Raman gain coefficient was directly measured over a bandwidth of 120 nm – covering the upper S-, C- and lower L-bands – with the Raman pump being injected into different combinations of fiber cores and using either co- or counter-propagating signal. Second, we analyzed the spectral power tilt induced by SRS when transmitting a wavelength-division multiplexed signal spanning the entire C-band from 1529.4 nm to 1564.2 nm, which was found to be in agreement with the Raman gain coefficient measurements. Measurements performed on a co-deployed standard single-mode fiber (SMF) produced similar results. This observation, together with the notion that the Raman gain coefficient should be similar in MCFs and SMFs, validates our earlier derived model of SRS in fibers with strong mode mixing.