Effective negative Kerr non-linear coefficient using highly non-linear fibers: A scalable backward propagation approach

We have numerically evaluated optical backward propagation (OBP) by the conjunction of dispersion compensating fiber (DCF) and a non-linear compensator (NLC) devised by effective negative Kerr non-linear coefficient using two highly non-linear fibers (HNLF) to compensate fiber transmission impairments, i.e. chromatic dispersion (CD) and non-linearities (NL). The OBP module is evaluated for dual-polarization (DP) mary (m=4,16,32,64,256) quadrature amplitude modulation (QAM) in 112 Gbit/s coherent transmission over standard single mode fiber (SMF). We have also proposed a intensity limited optical backward propagation module (IL-OBP) by using a self-phase modulation-based optical limiter with an appropriate pre-chirping to compensate for the intensity fluctuations in the transmission link. Our results depict that in highly non-linear sensitive 256QAM transmission, we have observed a 40% increase in the transmission distance by implementing IL-OBP as compared to conventional OBP.