NEC has announced the successful experimental demonstration of 1.15-Tb/s ultra-long haul optical transmission over 10,000 kilometers using optical superchannel technology. This is the first instance that a terabit/s channel generated from a single laser source has been transmitted over such a distance. Four superchannels were transmitted together by wavelength division multiplexing (WDM) to achieve a total capacity of 4 Tb/s and a spectral efficiency of 3.6 b/s/Hz. The results clearly demonstrate that practical high-capacity transmission for transoceanic communication can be achieved using cost-effective superchannel technology.
NEC’s system uses state-of-the-art hardware and advanced techniques, including optical multi-tone generation, large-core/ultra low-loss fiber, intradyne digital coherent detection, and digital equalization at higher oversampling, along with well-established technologies such as EDFAs and DP-QPSK modulation. The experiment yielded a 2-dB system margin above the hard decision FEC threshold without using processing-intensive MAP or MLSE algorithms.
