40 Gb/s and 4 x 40 Gb/s TDM/WDM standard fiber transmission

We investigate the possibilities of 40 and 4 x 40 Gb/s time division multip lexing wavelength division multiplexing (TDM/WDM) return-to-zero (RZ) trans mission over embedded standard single-mode fibers (SMF) at a transmission w avelength of 1.55 mu m both experimentally and theoretically. Dispersion of the SMF is compensated by a dispersion compensating fiber (DCF), Transmiss ion over a span of 150 km of SMF in the single-channel case and of 100 km S MF in the multichannel case are reported. Numerical calculations are employ ed to investigate the possibility of cascading the spans both for single-ch annel and multichannel transmission. For single-channel transmission, it is shown that optimum performance is achieved with post-compensation of the D CF, The input power at the SMF and DCF input have to be chosen carefully, F or four channel transmission, the performance is mainly limited by residual dispersion in the outermost wavelength channels. It is shown numerically t hat improvement is achieved by employing the newest type DCF which also com pensates the dispersion slope of the SMF. For a WDM channel separation of 2 nm no significant additional degradation due to cross-phase modulation (XP M) or four-wave mixing is observed.