Performance analysis is carried out to evaluate the effect of XPM on a Dispersion Managed (DM) 40Gb/s optical soliton transmission using direct detection, in the presence of Group Velocity Dispersion (GVD), Self-Phase Modulation (SPM), and Amplified Spontaneous Emission (ASE) in this chapter. It is found that for a distance of 2000 km, a power penalty of 1.9 dB is required to achieve a BER of 10-9 when XPM is taken into consideration. This power penalty increases with increasing neighbouring channel power and decreases with increasing channel separation. The system performance is also shown to be dependant on the system dispersion whereby the optimum dispersion is linked to the channel input power.
TopTheoretical Analysis
Using the slowly-varying envelope approximation, the propagation of the two channels along the transmission medium is governed by the Nonlinear Schröndinger Equation (NLS). For this analysis, we consider the attenuation factor, the second and third order dispersion coefficients (linked to GVD), the Raman shift as well as the SPM and XPM effects given as follows:
Channel 1:
(3.1)Channel 2:
(3.2)
where
represents the n
th channel’s attenuation parameter,
represents the n
th channel’s second order dispersion parameter,
represents the n
th channel’s third order dispersion parameter,
represents the n
th channel’s nonlinearity coefficient,
represents the n
th channel’s Raman shift, and
represents the walk-off parameter between channels 1 and 2.