Optimization of dispersion compensation for long distance 40 Gbit/s soliton transmission lines by the Q-map method

We investigate periodic dispersion compensated 40 Gbit/s soliton transmission lines by a numerical simulation and transmission experiment. We developed the simulation method for the optimization of these lines using Q-maps. The optimal dispersion compensation becomes a constant value of +/-20 ps/nm in different compensation periods, because of the optimal strength of the dispersion management. In the experiment, we evaluated transmission performance in the parameters of signal wavelength, signal power, and the location of dispersion compensation elements. The location is quite important in the design of such lines. In the 640 km transmission experiment using 2-pieces of dispersion compensation fibers, we observed error-free transmission in the wavelength range of 1.2 nm in the optimally designed line. This line design is practical for the next generation of 40 Gbit/s based communication systems.