WDM/SDM transmission of 10 x 128-Gb/s PDM-QPSK over 2688-km 7-core fiber with a per-fiber net aggregate spectral-efficiency distance product of 40,320 km⋅b/s/Hz

Abstract

We demonstrate 2688-km multi-span transmission using wavelength-division multiplexing (WDM) of ten 50-GHz spaced 128-Gb/s PDM-QPSK signals, space-division multiplexed (SDM) in a low-crosstalk 76.8-km seven-core fiber, achieving a record net aggregate per-fiber-spectral-efficiency-distance product of 40,320 km·b/s/Hz. The demonstration was enabled by a novel core-to-core signal rotation scheme implemented in a 7-fold, synchronized recirculating loop apparatus.

Review of Space-Division Multiplexing Technologies in Optical Communications

“…In such long-haul transmissions, a recirculation loop is indispensable whose configuration is distinguishing. A 2688-km transmission distance was achieved by using 7-fold, 76.8 km of 7-core MCF [51,52]. In every loop, the source signal was launched to every core in sync through an optical switch, and simultaneously, core assignment was rotated in a cyclic fashion to average the variation of each core.…”

Petabit/s Optical Transmission Using Multicore Space-Division-Multiplexing

“…However, it seems difficult to employ higher order multi-level signals due to the excessive crosstalk. For seven core fibers, crosstalk under −30 dB has been realized, and QPSK transmission with 15-b/s/Hz aggregate SE and 32-QAM-OFDM transmission with 60-b/s/Hz aggregate SE have been reported [7], [8].…”

Recent Progress in Space-Division Multiplexed Transmission Technologies

“…MDM transmission employing orbital angular momentum (OAM) modes [32] has also demonstrated where 400 Gb/s QPSK data was transmitted recently over 1.1 km [33]. SDM transmission utilizing MCFs with low crosstalk, on the other hand, have also seen many experimental demonstrations on high-capacity transmission of 100 Tb/s, 300 Tb/s up to 1 Pb/s, employing uncoupled 7-core, 19-core, and 12-core MCFs [34][35][36][37][38], respectively or long distance transmission over 1,000 km [39][40]. Multi-mode (MM) or multi-core (MC) optical amplifiers are strongly required for long-haul systems and should be major enablers to make SDM systems cost-effective and energy-efficient compared to present systems.…”