Abstract-An approach based on linearization that allows us to calculate the timing and amplitude jitter for arbitrary pulse shapes in dispersion-managed fibers is developed. We apply this approach to calculate the jitter for dispersion-managed soliton, return-to-zero (RZ), and nonreturn-to-zero (NRZ) transmission formats. We then estimate the bit error rates. The approach described here yields more precise results than Monte Carlo simulations at a fraction of the computational cost.

Abstract-We have developed a model that accurately predicts the dynamics of the signal pulses and the growth of amplified spontaneous emission noise in a dispersion-managed soliton pulse train propagating in a recirculating fiber-loop experiment. Theoretically predicted dependencies of the amplitude and phase margins for the marks and the amplitude margin for the spaces as a function of distance are in remarkable agreement with the experiments. This model allows us to determine the key physical effects that limit the propagation distance in our experiments.Index Terms-Amplitude margin, amplified spontaneous emission noise, dispersion-managed soliton (DMS), excess gain, filter, phase margin, pulse dynamics, timing jitter.

We numerically simulated long-distance, high-bit-rate, wavelength division multiplexed (WDM) transmission in dispersion-managed systems. We investigated return-to-zero (RZ) and nonreturn-to-zero (NRZ) modulation formats with amplitude and phase modulation. Consistent with earlier experiments, we find that the chirped return-to-zero (CRZ) modulation format has significant advantages over the NRZ modulation format in WDM systems. We elucidate the physical reasons for these advantages. We then discuss, in detail, the dynamics of the CRZ systems, carefully distinguishing noise effects, single-channel nonlinear effects, and multichannel nonlinear effects. In this way, we provide a physical basis for understanding CRZ systems that should prove useful for future system design. In particular, we find that the pulse evolution is dominated by linear dispersion and that the spread in the eye diagrams is dominated by signal-spontaneous beat noise, just like in linear systems. However, we also find that symmetric dispersion compensation performs better than asymmetric dispersion compensation, due to the effects of nonlinearity. Additionally, we find that interchannel nonlinearities spread the eye diagrams without changing the dynamical behavior. Thus, the system is quasilinear in the sense that its properties resemble those of linear systems, but nonlinearity plays an important role.Index Terms-Amplified spontaneous emission (ASE) noise, chirped return-to-zero (RZ), nonlinearity, quasilinear, slope compensation, symmetric, wavelength division multiplexing (WDM).