BER Penalty Induced by Coherent MPI Noise in FTTH Optical Links

We measure the coherent multipath interference noise and the associated bit error rate (BER) penalty affecting an optical link in which a fraction of the signal is scattered from the fundamental into the first-order mode of a bend insensitive fiber, to mimic a situation that can be encountered in fiber to the home deployments. Our set up allows changing the relative weights and the phase difference between the two interfering modes, and measuring the BER in stationary and dynamical settings, namely with the interference conditions kept fixed or continuously varied during the measurement cycle, respectively. We show that the BER penalty detected in the dynamical measurements can be entirely ascribed to the stochastic variations of the received intensity, and we demonstrate a good agreement between the experimental data and the results of our numerical simulations.