Ultra-wideband discrete Raman amplifier optimization for single-span S-C-L-band coherent transmission systems

Research output: Contribution to journalArticlepeer-review


We experimentally compare the performance of two key ultra-wideband discrete Raman amplifier structures, a cascaded dual-stage structure and an in-parallel dual-band structure, in fully loaded S-C-L band coherent transmission systems over 70 km of single-mode fiber. Our results show that dual-band discrete Raman amplifier with minimized backreflections can effectively avoid unstable random distributed feedback lasing, reduce the noise figure, and therefore improve the transmission performance for signals at shorter wavelengths, versus the cascaded dual-stage structure. The average noise figure for S-band signals is 6.8 dB and 7.2 dB for the dual-band structure and cascaded dual-stage structure, respectively, while the average S-band Q2 factor is similarly improved by 0.6 dB. Moreover, the cascaded dual-stage discrete Raman amplifier requires guard bands around the 1485-nm and 1508-nm pumps as the signal and pump wavelengths overlap, which results in a bandwidth loss of ∼10 nm and reduces the potential net data throughput to 28.6 Tb/s for 30-GBaud DP-16QAM signals. However, the dual-band structure can utilize the bandwidth more effectively, which leads to a higher estimated net data throughput of 31.2 Tb/s.
Original languageEnglish
Article number6472
Number of pages4
JournalOptics Letters
Issue number24
Early online date9 Nov 2022
Publication statusPublished - 15 Dec 2022

Bibliographical note

Published by Optica Publishing Group under the terms of the Creative Commons Attribution 4.0 License [https://creativecommons.org/licenses/by/4.0/]. Further distribution of this work must maintain attribution to the author(s) and the published article’s title, journal citation, and DOI.

Funding: H2020 Marie Skłodowska-Curie Actions (814276); Royal
Society (IEC\NSFC\211244); Engineering and Physical Sciences Research
Council (EP/V000969/1).

Acknowledgments: The authors thank Socionext for providing DACs, Lumentum for providing modulators, and Coherent for providing pump lasers.


Dive into the research topics of 'Ultra-wideband discrete Raman amplifier optimization for single-span S-C-L-band coherent transmission systems'. Together they form a unique fingerprint.

Cite this