Fig. 1. Principle of OPC.

Fig. 2. (i) Numerical model of 112  Gbit/s DP-64-QAM coherent transmission [PBS: polarization beam splitter, PBC: polarization beam combiner]; (ii) OPC-NM module; (iii) SPM-based all-optical IL; (iv) OBP module; (v) graphical representation of optical power along FL, MLSI, and PD-SI.

Fig. 3. Q factor (dB) as a function of signal input launch power in 112  Gbit/s DP-64-QAM coherent transmission over 800 km SMF for diverse fiber transmission impairment compensation methods.

Fig. 4. Constellation plots after EDC, OBP, OPC-NM, and DBP for 112  Gbit/s DP-64-QAM at 0 dBm signal launch power.

Fig. 5. System performance at various transmission distances for 112  Gbit/s DP-64-QAM at −4  dBm signal launch power.