Fig. 1. Mode division multiplexing amplification and transmission system

Fig. 2. Schematic diagrams of FM-EDFA based on FM-IWDM. (a) FM-EDFA experimental device; (b) structure of homemade FM-IWDM component; (c) relative refractive index difference of FM-EDF

Fig. 3. Gain and noise figure versus pump power of LP₀₁, LP_11a, and LP_11b channels. (a) Gain and differential modal gain; (b) noise figure

Fig. 4. Transmission performance of mode division multiplexing channels with and without FM-EDFA. (a) Bit error rate; (b) polarization dependent loss

Fig. 5. Gain and DMG versus pump power of LP₀₁ and LP_11b channels

Fig. 6. Sensitivity degradation and polarization dependent loss of LP₀₁ and LP_11b channels versus pump power. (a) Sensitivity degradation; (b) polarization dependent loss