Behavior and measurement method of inter- core crosstalk in multicore fibers with core-dependent loss

We quantitatively discussed the effect of core-dependent loss (CDL) on the crosstalk (XT) of multicore fibers (MCFs). In practical ranges of XT and CDL, CDL has no significant effect on power coupling coefficients and XT between cores. Therefore, taking into account the CDL-induced signal attenuation difference among cores is sufficient when considering the signal-to-XT ratio in an MCF with CDL. We also analytically investigated the effect of CDL on XT measurements, and found that the effects of the CDLs induced in an MCF as a measurement target and a measurement setup (including input/output devices) can be canceled in the geometric mean of linear values (or the arithmetic mean of decibel values) of the XT by switching the source core and destination core of the XT. (c) 2022 Optica Publishing Group under the terms of the Optica Open Access Publishing Agreement