Experimental demonstration of 680Gbit/s capacity for the medium-haul undersea lightwave cable systems

摘要

An increasing demand of the data communication especially represented by the Internet traffic needs more capacity for the trunk line of global network. As the undersea cable system is the major player of the global network, there is a high pressure to expand the transmission capacity of the lightwave communication system. As a matter of fact, 640Gbit/s per fiber capacity was already reported for the trans-oceanic distance under the laboratory condition [1]. Even though, this demonstration utilizes a forward error correction (FEC) that would be used to establish the system margin, and there is no margin to design commercially available system based on this experiment. From the practical point of view, to achieve 10~(-9) bit error rate (BER) is one criterion to design a commercial system with sufficient margin. On the other hand, 500Gbit/s transmission was already demonstrated for the medium-haul system with sufficient system margin [2]. As the medium-haul system is applicable for the regional systems such as Asian system and Mediterranean system, an investigation of the system capacity expansion is quite important. In this paper, we demonstrate 68WDM, 10Gbit/s transmission over 3270 km. A combination of large effective area fiber and small dispersion slope fiber is applied to the transmission line to compromise both low nonlinear characteristic and small cumulative dispersion. The results proved the feasibility of the medium-haul system with more than several hundreds Gbit/s capacity.