Comparison of N x 40 Gb/s and 4N x 10 Gb/s WDM transmission over standard single-mode fiber at 1.55 μm

We compare the performance of dispersion-managed 4×40, 16×10, and 16×40 Gb/s wavelength-division-multiplexed transmission over 1000-km standard single-mode fiber operating at 1.55 μm. It is shown, that for N×40 Gb/s, the system performance is mainly limited by the degradations of each single channel. No significant additional degradation due to cross-phase modulation or four-wave mixing could be observed. Moreover, it is shown that focusing on the total fiber-input power, both transmission schemes, 4×40 Gb/s at 100-GHz channel spacing and 16×10 Gb/s at 25-GHz channel spacing, yielding the same total bandwidth show almost identical performance.