We investigate the impact of intercore crosstalk on the achievable transmission distance of
three square quadrature amplitude modulation (QAM) formats. We show that increasing
intercore crosstalk across an 18 dB range starting from-43.4 dB/100 km reduces the
achievable transmission distance for all formats, with a greater impact on higher order
modulation formats. For a crosstalk level arising from equal signal launch power in each
core of a homogeneous 7-core fiber, we measure a reduced transmission distance at BER …

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.