Comparative study of pulse interactions in optical fiber transmission systems with different modulation formats

We compare nonlinear channel interactions in classical soliton, periodicall y-stationary dispersion-managed soliton ( DMS), and chirped-return-to-zero (CRZ) systems. We studied multichannel systems with a single pulse in each channel and a more general case with multiple bit streams in each channel. First, we nd that in classical soliton systems, the distortions are reversi ble, while in the DMS and CRZ systems hey are not. Second, we nd hat he cla ssical soli on system shows no increase in he degradation as he number of c hannels increases, while both he DMS and CRZ systems do show an increase in the degradation. (C) 2001 Optical Society of America.