E-, S-, C- and L-band coherent transmission with a multistage discrete Raman amplifier

Abstract

We report for the first time an ultra-wideband coherent (UWB) WDM transmission over a 70 km standard single mode fibre (SSMF) solely using a multistage discrete Raman amplifier (DRA) over the E-, S-, C- and L-bands of the optical window. The amplifier is based on a split-combine approach of spectral bands enabling signal amplification from 1410-1605 nm over an optical bandwidth of 195 nm (25.8 THz). The proposed amplifier was characterized with 143 channelized amplified spontaneous emission (ASE) dummy channels in the S-, C- and L-bands and 4 laser sources in the E-band (1410–1605 nm). The amplification results show an average gain of 14 dB and a maximum noise figure (NF) of 7.5 dB over the entire bandwidth. Coherent transmission with the proposed amplifier was performed using a 30 Gbaud PM-16-QAM channel coupled with the ASE channels over a 70 km SMF. The ultra-wideband transmission using the tailored multistage DRA shows transmission bandwidth of 195 nm with a maximum Q2 penalty of ∼4 dB in E- and S-band, and ∼2 dB in C- and L-band.

Recent advances in wideband Raman amplifiers

“…In more recent experiments, this architecture has been extended to cover the E+S+C+L-bands by augmenting the dualstage architecture described above with an extra parallel section comprising an additional set of [1325,1345,1365] nm pumps, in a so-called split-combine approach 18 . The resulting DRA enables signal amplification from 1410-1605 nm, over an optical bandwidth of 195nm, with an average gain of 14dB and a maximum noise figure of 7.5dB.…”

Multi-Band ESCL Transmission Supported by Bismuth-Doped and Raman Fiber Amplification

“…The Raman amplifier features a flexible operation wavelength, if provided with necessary pump lasers, the ability to create a flat-top or tilted gain shape [14], and has been recently used for ESCL-band transmission over 70 km [17]. In contrast, the BDFA features an extraordinary gain of 38 dB [18], [19], an optical power conversion efficiency higher than 30% [18], and a noise figure as low as 4.5 dB [20].…”

Multi-Band Transmission Over E-, S-, C- and L-Band With a Hybrid Raman Amplifier

“…Similarly, in the S-, C-and L-band, amplification bandwidths of 150 and 135 nm have also been achieved using a dual-stage and dual-band DRAs [26], [27]. DRAs have also been demonstrated over the E-, S-, C-and L-band, where an amplification bandwidth of 210 nm was achieved and 200 Gbit/s per channel transmission was performed over signals in the range of 1410-1605 nm potentially enabling a transmission bandwidth of 21.8 THz [28], [29]. Together with experimental designs and demonstrations using Raman amplifiers, real-time nonlinear modelling of MBT is an essential tool to introduce intelligence, achieve the best resource allocation and maximise system throughput in the optical networks [30], [31].…”