Impact of physical effects onto the optimal signal power in CWDM optical networks

Nowadays in optical networks there is a trend to extend the maximum transmission distance. Several technical solutions are known but the simplest one is to increase the signal power in the optical fiber. However, the nonlinear behavior of the optical fiber limits the signal power e.g. the span of the all-optical network. This paper presents an analytical model and calculation results for the signal quality degradation in an 8-channel and an 18-channel, 2.5 Gbps coarse wavelength-division- multiplexing (CWDM) system. Based on the proposed model and performed analysis we give the optimal value of the signal power at the transmitter point.