Performance of DBPSK in a 5 /spl times/ 10 Gb/s mixed modulation format Raman/EDFA WDM system

The impact of varying the pulse format as well as the data format of side channels on a differential binary phase-shift-keyed (DBPSK) center channel, as a function of channel spacing and propagation distance, was examined for the first time in a 5 /spl times/ 10 Gb/s Raman/erbium-doped fiber amplifier wavelength-division-multiplexed recirculating loop. The data format of the side channel was either on-off keying (OOK) or DBPSK, while its pulse format was either 50% return-to-zero or nonreturn-to-zero. For the system studied, it was found that the side channel OOK data format was always more detrimental than its pulse format to the performance of the DBPSK center channel.