Variation in the performance of multispan 10-Gb/s systems due to the group delay ripple of dispersion compensating fiber Bragg gratings

The variation in the performance of multispan lightwave systems that use dispersion-compensating fiber Bragg gratings (FBGs) is characterized in terms of the peak-to-peak group delay ripple over the -1dB bandwidth of the gratings. The irregular dependence of the group delay ripple on wavelength, and the variability in the properties of the group delay ripple for nominally identical gratings make it difficult to predict the overall reflection spectrum for a cascade of gratings. The uncertainty in the overall spectrum must be considered in the system design process. By considering 2401 distinct configurations for the gratings in a four-span 320-km system, simulation results are presented that specify the requirement for the group delay ripple in order for the system performance to remain within a specified penalty.