High-Throughput and Long-Distance Transmission With >120 nm S-, C- and L-Band Signal in a 125μm 4-Core Fiber

We investigate recirculating transmission of a wideband S-, C- and L-band signal in a 4-core fiber. We transmit 552 x 25 GHz spaced, 24.5 GBd channels, covering more than 120 nm bandwidth from 1487.8 nm to 1608.33 nm through each core of the multi-core fiber (MCF), which has the same 125μm cladding dimeter as standard single-mode fiber. We first use PDM-16QAM modulation and measure performance at distances up to 3001 km, corresponding to 43 spans of the 69.8 km MCF. At this distance we measure a decoded throughput of 319 Tb/s or 342 Tb/s when estimating from the generalised mutual information (GMI). Extending the transmission distance to 8027 km, a selection of PDM-QPSK modulated channels across the spectrum were received with an average GMI estimated data-rate of 83.7 Gb/s. These results show that wideband transmission including the S-band has the potential to increase data-rates in long-haul optical fiber transmission. Further, our experiment confirms that 125 μm diameter MCFs can multiply transmission capacity whilst offering benefits of resource sharing and integration, expected in SDM systems.