Intercore Crosstalk in Homogeneous Multicore Fibers: Theoretical Characterization of Stochastic Time Evolution

A time-varying phase shift associated with each phase matching point of homogeneous weakly coupled multicore fibers is proposed to describe the stochastic time evolution of the intercore crosstalk (ICXT) observed experimentally. This model for the stochastic ICXT time evolution represents a generalization of current ICXT theoretical models and potentiates the development of new time-adaptive ICXT mitigation techniques. The model is first proposed considering a single polarization scheme, and is then generalized to a dual polarization scheme and to account for the polarization coupling between cores. Comparison between spectrograms of the crosstalk transfer function (XTTF) amplitude evaluated using the single polarization model and measured experimentally shows excellent agreement for short (few minutes) decorrelation times. For large decorrelation times (above 1 h), some differences in the behavior of the time evolution of the XTTF amplitude are observed. Nevertheless, excellent match between the mean and variance of the XTTF amplitude evaluated from the model and from analytical expressions proposed in the literature is observed for short and large decorrelation times. It is also shown that the decorrelation time of the short-term average crosstalk remains unchanged when the dual polarization scheme is considered. Similar spectrograms of the XTTF obtained with the single and dual polarization ICXT models are also shown.