Numerical demonstration of mode-division multiplexing transmission over dual-mode photonic crystal fiber enabled by fiber couplers

Abstract A 2 × 6-Gb/s mode-division multiplexing (MDM) transmission over 70-km dual-mode photonic crystal fiber (PCF) is numerically demonstrated by using a long-period fiber grating (LPFG) as the mode converter between orthogonal LP 01 and LP 11 modes. The mode multiplexing/demultiplexing is achieved by adjusting the interaction parameters of fiber couplers (FCs) to separately forward signals to straight path and cross path. By doing this, the simulation results for the proposed MDM transmission show negligible mode crosstalk and low power penalty.