50.47-Tbit/s Standard Cladding Coupled 4-Core Fiber Transmission Over 9,150 km

Abstract

Since optical submarine cable systems are a part of the global communications infrastructure, their total capacity must be continuously and dramatically enlarged. Recently, methods how to maximize the transmission capacity under electrical power limitations have been studied, and it has been reported that a single band (C-band only) transmission system with more fiber pairs (FPs) could be a promising technology. This finding has triggered work on submarine cables with more FPs. For a further increase in FPs in optical submarine cable systems, which also have space limitations in existing cable designs, spacedivision multiplexing (SDM) technologies such as multi-core fibers (MCFs) and multi-mode fibers (MMFs) could be promising solutions. In particular, 125-m standard cladding SDM fibers are attractive for early deployment in submarine cable systems since they are expected to have high productivity and high mechanical reliability similar to existing single-mode fibers (SMFs) with the same cladding diameter. In this paper, we report transpacific MCF transmission over a 30-nm bandwidth using standard cladding ultralow-loss coupled 4-core fibers, extending our previous work. The Q 2 -factors of 608 (4 core  152 WDM) SDM/WDM channels modulated with 24-Gbaud DP (dual polarization)-QPSK (quadrature phase shift keying) exceeded the assumed forward error correction (FEC) limits after a 9,150-km transmission. As a result, transmission capacity of 50.47 Tbit/s and a capacity-distance product of 461.8 Pbit/s•km were achieved for standard cladding diameter SDM fibers.

Randomly-Coupled Multi-Core Fiber Technology

“…Although multiple-input-multiple-output (MIMO) digital signal processing (DSP) is necessary for undoing mode mixing among the cores, ultralong-haul transmission over >12 000 km using off-line processing [24], [28] and real-time 7200-km transmission using online processing on a field-programmable gate array (FPGA) have been demonstrated [29]. Wideband transmission experiments have also been performed in the C-band [30] and in C + L-band [31].…”

Research on fusion splicing technology of 7-core fiber

“…Space division multiplexing (SDM) is an effective method to overcome the capacity crunch of optical communication systems based on the current conventional single-mode fiber (SMF) [12] . Increasing and making full use of the spatial dimension is the only way to further improve the optical fiber communication capacity physically, and also provides a new degree of freedom for network switching [13][14][15] . In the SDM transmission system, different signals can be transmitted simultaneously through multiple spatial paths.…”