We compared the transmission performances of 600 Gbit/s PM‐64QAM WDM signals over 75.6 km of single‐mode fibre (SMF) using EDFA, discrete Raman, hybrid Raman/EDFA, and firstorder or second‐order (dual‐order) distributed Raman amplifiers. Our numerical simulations and experimental results showed that the simple first‐order distributed Raman scheme with backward pumping delivered the best transmission performance among all the schemes, notably better than the expected second‐order Raman scheme, which gave a flatter signal power variation along the fibre. Using the first‐order backward Raman pumping scheme demonstrated a better balance between the ASE noise and fibre nonlinearity and gave an optimal transmission performance over a relatively short distance of 75 km SMF.
Bibliographical noteFunding Information:
Funding: UK Engineering and Physical Sciences Research Council (EPSRC) Grant EP/S003436/1 (PHOS), EP/V000969/1 (ARGON), Polish Ministry of Science and Higher Education Grant 12300060, and National Natural Science Foundation of China Grant 61975027.
© 2021 by the authors. Licensee MDPI, Basel, Switzerland.
- Optical fibre communication
- Raman amplification