Kuang-Yi Wu

Network performance for cascaded dispersion-free slicers

The impact of cascaded spectral Slicers on network performance is investigated in this paper. For a dispersive spectral Slicer, its dispersion is inversely proportional to the square of its channel spacing. When many narrow-band spectral Slicers are cascaded together, the total dispersion can cause significant penalty on system performance. We demonstrated the deleterious effects on system performance caused by the dispersion of cascaded spectral Slicers. To solve this problem, we applied a signal processing technique to design theoretically dispersion-free spectral Slicers. The design principle and simulation results of dispersion-free spectral Slicers are presented. Based on this signal processing technique, six dispersion-free 50-GHz Slicers were made and cascaded together. The total group delay ripples across spectrum within ±12GHz around center frequencies are less than ±0.8ps, which are much less than the group delay variation of ±14ps within the same bandwidth for dispersive Slicers. The power penalty of cascade dispersion-free Slicers is investigated by deploying them in a 16-channel OC-192 WDM (wavelength-multiplexing division) link. The measurement result shows no noticeable power penalty.