Dynamic Model for Coupled-Core Fibers

Capacity trends in fiber optical communication systems are closely related to space-division multiplexing (SDM) solutions. A coupled-core fiber (CCF) is one of the most promising SDM candidates for a high data rate transmission because of its tolerance to nonlinear effects and reduced accumulation of group delay spread (GDS) with distance. As the modes of the cores in CCFs are strongly coupled, a communication link requires multiple-input multiple-output (MIMO) processing to recover the input signals. MIMO algorithms, in turn, operate with the different number of finite impulse response taps that represents the memory length of an equalizing filter. The calculation of the number of taps requires the knowledge of GDS, which can be estimated from the received data if a channel model is given. Moreover, if the model accounts for dynamic (time varying) effects it can be used to test the adaptive performance of MIMO equalizer. In this work we propose a straightforward dynamic random coupling model for CCFs. We investigate the dynamic behavior of group delays and impulse responses and also derive and analyze frequency and time autocorrelation functions.