{'fraction_non_alphanumeric': 0.01509433962264151, 'fraction_numerical': 0.0025157232704402514, 'mean_word_length': 5.368, 'pattern_counts': {'":': 0, '<': 0, '<?xml version=': 0, '>': 0, 'https://': 0, 'lorem ipsum': 0, 'www.': 0, 'xml': 0}, 'pii_count': 0, 'substrings_counts': 0, 'word_list_counts': {'cursed_substrings.json': 0, 'profanity_word_list.json': 0, 'sexual_word_list.json': 0, 'zh_pornsignals.json': 0}}
Optimized dispersion maps for suppression of cross-phase modulation in WDM systems

Based on an analytical model which is verified by numerical simulations, we study the influence of the dispersion map on XPM induced signal degradations in long-haul WDM systems for different fibre types. Distributed undercompensation is shown to be an optimum choice for 10 Gb/s per channel transmission. Statistical studies of map variations confirm, that moderate deviations from the optimum dispersion map further reduce the XPM limited reach. For transmission over standard single-mode fibre, XPM generated in the dispersion compensating fibers which are required for a compensation of the large dispersion of the transmission fiber may impose a stringent limitation for terrestric ultra-long haul systems.