Nonlinear Compensation Assessment in Few-Mode Fibers via Phase-Conjugated Twin Waves

In this paper, we further explore the concept of phase-conjugated twin waves (PCTW) for nonlinear cancellation in space-division multiplexed (SDM) systems. Previously, we demonstrated that the PCTW technique can successfully provide nonlinear cancellation in SDM systems. In this paper, we investigate the cases where two and four spatial modes are copropagating in a multimode fiber, considering three link lengths (1000, 3200, and 8000 km). Weak- and strong-coupling regimes are also evaluated. Our numerical simulation results show an average performance improvement >10 dB after a 1000 km transmission link.