Spectral Features with the Temporal and Spatial Mode-coupling Dynamic in a Few-mode System

We propose a novel mode-coupling (MC) model of the few-mode fiber (FMF) system through simultaneously considering the spatial and temporal dependency of the random perturbation. We investigate the spectral features in the scenarios of the 3- and 6-mode transmission system and observe the multiple-peak spectral response. In the time domain, the effective suppression of the signal fluctuation could be achieved by largening the coupling strength or the spatial randomness. In the frequency domain, the single-peak response around the zero-frequency and the multiple-peak response as a modulated signal were obtained from the output spectra when the multiple-mode interaction happened.