Efficient design of high-capacity dense wavelength-division multiplex systems

An efficient design methodology for high-capacity dense wavelength-division multiplexed systems is presented. In contrast to complex and time-consumin g numerical simulations, analytical equations and heuristic approximations are used to model the system performance. They facilitate first-order perfo rmance estimates and the identification of limiting effects even for multi- Tb/s systems within a few seconds. Taking into account local and accumulated group velocity dispersion, impair ments due to fibre nonlinearities are described as a function of the averag e optical input power per channel. In combination with the degradation of t he optical signal-to-noise ratio caused by optical amplifier noise the maxi mum transmission distance versus optical input power can be determined. The validity of the models is verified by means of numerical simulations an d system experiments. The dependence on data rate, modulation format, fibre type and dispersion compensation scheme is determined. Practical examples illustrate the usefulness of our design approach.