In the dense wavelength division multiplexing (DWDM) there are many factors
affecting their performance. These factors can be divided into linear and nonlinear
effects. The linear effects such as chromatic dispersion (CD) and polarization mode
dispersion (PMD) can be compensated easily by dispersion compensation fiber
(DCF) or fiber Bragg gratings (FBG). The nonlinear effects are the major and most
dangerous factors that affect the signal quality and the overall performance of the
DWDM. The nonlinear effects can be divided into self-phase modulation, cross
phase modulation, four waves mixing, stimulated Brillion scattering and stimulated
Raman scattering. This paper discusses the nonlinear effects of the DWDM system
and the different ways to overcome these effects to improve the overall signal
quality. This simulation analysis was performed using Optisystem (7) simulator