Bi-directional Erbium Doped Fiber Amplifier in XPM Limited High-capacity DWDM System in C Band

This article is focused on high-capacity DWDM system with bi-directional erbium doped fiber amplifier (EDFA). Optical amplification is important process in long-haul optical networks. EDFA is the best known for the ability to amplify broadband signals. One of the advantages of EDFA is that amplifiers are not required for each channel in multichannel transmission. The downside of EDFA is the creation of fiber nonlinear effects. With the ever-increasing transmission distance and network capacity it is not fully possible to prevent negative influence of fiber nonlinear effects such as self-phase modulation (SPM), cross-phase modulation (XPM) and four wave mixing (FWM). Because nonlinear effects are power sensitive, optimalization of EDFA is crucial for the performance of the whole system. In this paper we present 32-channel DWDM system (according to the recommendation ITU-T G.694.1) with capacity of 1.28 Tb/s and nonlinear single-mode optical fiber (SMF) with symmetrical and non-symmetrical EDFA. The aim of the work is to find out which of the EDFA schemes is better for our designed DWDM system. The resulted signals were analysed and BER and Q-factor values were calculated. Non-symmetrical scheme can achieve signal level 21.325 dBm and OSNR 4.771. For symmetrical scheme is signal level is 21.797 and OSNR is 4.617.