FWM mitigation in 2.56 Tb DWDM-OTDM optical link employing modified duobinary modulation and dispersion compensation

In this paper, FWM reduction in 40 Gbps DWDM-OTDM optical network of 64 channels with 50 GHz frequency spacing is analyzed using modified duobinary return-to-zero (MDRZ) modulation. Due to the decrease in channel spacing, the nonlinearity in the fiber such as Four-Wave Mixing (FWM) increases due to which the performance of dense wavelength division multiplexing (DWDM) optical link degrades. Therefore, FWM reduction has significant role in enhancing the spectral efficiency to increase the bandwidth for long-haul communication. Symmetrical compensation technique is used to diminish the FWM and OTDM is used for expansion of the users per channel. The spectral efficiency of proposed system has been improved by increasing the transmission length of quality signal. Optimized system is simulated using OptSim simulator and examined under dispersion compensation management to reduce the nonlinearities. Modulation is enhanced and unequal channel spacing is incorporated to reduce the FWM. 40 Gbps MDRZ data is inferred by CW laser of -15 dBm to 15 dBm varied power. Optical link performance is interpreted by measuring Q-factor and BER.