Impact of inter-core crosstalk on the transmission distance of QAM formats in multi-core fibers

We investigate the transmission distance of three QAM modulation formats, in the presence of inter-core crosstalk in a 7-core fiber. We show that crosstalk limits transmission distance for all formats with a greater impact on higher order modulation formats. For a crosstalk level equivalent to equal signal launch power in each core, we measure a reduced transmission distance at BER=1.5×10
⁻²
of 17%, 23% and 36% for PDM-QPSK, PDM-16QAM and PDM-64QAM respectively.