Two extremely stable conditions of optical soliton transmission in periodic dispersion compensation lines

We investigated numerically nonlinear return-to-zero-pulse transmission thr ough periodic dispersion compensation lines and clearly demarcate the two e xtremely stable transmission conditions. One case uses anomalous dispersion fibers as the transmission line and the other case uses normal dispersion fibers. Linear dispersion compensation elements are used in both cases so t hat the average dispersions are in the slightly anomalous region. These two conditions have opposite frequency chirp, and the normal dispersion fiber case indicates better characteristics than the anomalous dispersion fiber c ase.