Reduction of intersymbol interference in dispersion-managed soliton systems compensated by chirped fibre gratings using nonlinear optical loop mirrors

We address the problem of group delay ripples in chirped fibre gratings on dispersion compensation in optical transmission systems. We show that the intersymbol interference, which is a highly harmful effect induced by the group delay ripples in transmission systems, can be substantially reduced by the use of nonlinear optical loop mirrors. This leads to an improvement of the system performance by more than one order of magnitude when compared with a grating-compensated dispersion-managed system without nonlinear optical loop mirrors. We find similar performances irrespective of whether the structure of group delay ripples is modelled by a sinusoidal function or the grating is modelled by the coupled-mode equations.