Abstract: Intensity dependence of the refractive index is known to be the major cause of nonlinear effects in optical fibers. These non-idealities’ effects are insignificant in the low power regime but become prominent when launch powers exceeds the threshold values. This seems to add to performance degradation due to the already present dispersion-induced pulse spreading. However, since fiber nonlinearities and dispersion present in the link tend to balance each other, complete dispersion-compensation results in low Q-parameter and high BER. The system can be significantly improved by optimizing the launch power and dispersion residue. In this work, extensive simulations have been performed to study the impact of launch power and dispersion residue on the performance of optical link to arrive at the optimal values. Main objective of the study is to minimize the BER at the receiver while optimizing the power and dispersion residue. A 100km optical link is established using 10Gbps-RZ transmission at an operating wavelength of 1552.5nm. Simulations show that in the low power regime, complete compensation (dispersion residue is zero) resulted in very low BER. Maximum Q parameter of 18 is achieved when the launch power is around 19dBm and DCF length is 12.5km i.e., dispersion residue is around 800ps/nm.
Keywords: Nonlinear effects, residual dispersion, Launch power, BER, DCF.