Abstract
Performance analysis is carried out to evaluate the effect of XPM on a dispersion managed 20Gb/s optical WDM transmission system using either On-Off Keying (OOK) or Differential Phase Shift Keying (DPSK) modulation, in the presence of GVD, SPM, and ASE noise in this chapter. It is found that to achieve a BER of 10-9 at a distance of 160 km, a 1.0 dB XPM power penalty is incurred for input channel power of 3 dBm in OOK transmission and 7 dBm in DPSK. The power penalty increases with input channel powers, but it is inversely proportional and exhibits oscillations with respect to channel separation. The oscillation is evenly spaced for DPSK but not for OOK and suggests the presence of optimum separation values. XPM penalty decreases when high dispersion fiber is used, and it also increases linearly with increasing dispersion slope. Small residual dispersion can reduce the penalty of nonlinear effects.