Interferometric crosstalk reduction by phase scrambling

Interferometric crosstalk, arising from the detection of undesired signals at the same nominal wavelength, may introduce large power penalties and bit -error rate (BER) floor significantly restricting the scalability of optica l networks, In this paper, interferometric crosstalk reduction in optical w avelength-division-multiplexing (WDM) networks by phase scrambling is theor etically and experimentally investigated. Enhancement of 7- and 5-dB tolera nce toward crosstalk is measured in a 2.5-Gb/s transmission link of 100 km and 200 km of SSMF, respectively. This result proves the feasibility of opt ical networking in the local area network/metropolitan area network (LAN/MA N) domain while tolerating the relatively high crosstalk levels of present integrated optical switching and cross-connect technology. Experiment is in good agreement with theory. Recommendations on the use of phase scrambling to reduce crosstalk in WDM systems are given.