Abstract

There is a huge increase of the capacity required by undersea system operators. To increase the capacity of a long-haul transoceanic submarine WDM transmission system, the spectral efficiency is a key parameter. The transmission experiments reported with spectral efficiency of 0.4 (bit/s)/Hz or better^1–5 exhibited however a minimum Q factor which is not sufficient to account for system margin required in an industrial submarine system. Indeed, time varying system performance impairment (1.2 dB), manufacturing impairment (0.5 dB), allowance for repair and aging (0.7 dB), represent about 2.4 dB impairment which should be taken into account in the transmission feasibility. In this experiment, we demonstrate for the first time that the NRZ format at 10 Gbit/s combined with a true 25 GHz spacing can be employed in a 1.12 Tbit/s 6300 km industrial transmission system since all the 112 transmitted channels exhibit a 2.7 dB margin above the Q factor required to get 10^–13 BER with a concatenated Reed-Solomon FEC with 7% redundancy.^6,7 The average system margin is 3.6 dB.

© 2002 Optical Society of America