50-GHz channel-spacing analysis in N/spl times/2.5-Gbit/s systems

Summary form only given. Cross-phase modulation (XPM) and four-wave mixing (FWM) have been studied in a link composed of five spans of 100 km of G652 fiber (0.22 dB/km) followed by a 6-dB loss (28-dB span). It is found that FWM, not XPM, determines the maximum system capacity (the effect of XPM is overcome by self-phase modulation). However, FWM does not forbid 50-GHz spacing transmission with high SNR. Eighty channels spaced by 50 GHz are transmitted over 500 km of G652 fiber. The line amplifiers provide +5-dBm output power for all channels (+24 dBm total) with a 5.5-dB noise figure. Penalties with back-to-back are low and consist of 0.5-dB due to SNR, and of a variable part, consistent with results obtained with five channels. It is therefore possible to increase the capacity carried on G652 fiber up to 100 Tbit/s.km by only increasing the channel count and the amplifiers output powers.