Aleksandr Donodin on TRANSNET, ECOC and his RAEng fellowship
Ahead of his invited talk "Optical Amplification in the S-band and Beyond: From Materials and Mechanisms to Practical Deployment" at ECOC 2026, Aleksandr Donodin reflects on his time with TRANSNET and ECOC, and looks ahead to future work with his RAEng Fellowship.
Alex has been a major contributor to TRANSNET's research and global reach. Over the past 4 years, he has authored 9 ECOC presentations and co-authored 12, including one post-deadline. ECOC 2022 in Basel was his first as a presenter, including the talk "38 dB Gain E-band Bismuth-doped Fiber Amplifier". When asked how his work has progressed since then, Alex told us:
"That 2022 result was essentially proof that a bismuth-doped fibre amplifier could deliver strong performance in a spectral region that conventional erbium-doped amplifiers cannot reach. Since then, the work has moved from “can we make it amplify?” to “can we make it practical?”—with lower noise, higher output power and energy efficiency, coverage across the O-, E- and S-bands, and validation in coherent multiband transmission systems carrying hundreds of terabits per second."
This first ECOC appearance remains particularly memorable for him, solidifying that his years of work on BDFAs were becoming part of a much wider multiband communications story. Due to the impact of COVID the previous two years, this was his first in-person conference during his PhD, and also the last (just 2 weeks before his submission deadline)! Another major highlight was seeing amplifier research feed into collaborative record-capacity system demonstrations, including the 430 Tb/s post-deadline result at ECOC 2025 - one of TRANSNET's most important results over the course of the programme.
"ECOC has been where many of the collaborations behind this work have developed, so it has become almost an annual record of how the research has progressed. ECOC remains perhaps my favourite with nice talks and good balance between industry and academia."
Alex hopes to add another highlight to the list with his invited talk this year “Optical Amplification in the S-band and Beyond: From Materials and Mechanisms to Practical Deployment.” In his own words:
"I am particularly excited about this talk because, although it will still place the work within the wider context of amplification beyond the conventional C- and L-bands, it gives me an opportunity to focus much more deeply on the S-band. Unlike the C-band, there is no single established amplifier solution, so I will compare several different approaches—including Raman, thulium-doped, bismuth-doped and hybrid bismuth–erbium amplification—and discuss the strengths, limitations and practical potential of each. The talk brings together work by many researchers over many years, and I hope it will offer a fuller picture of the S-band landscape than my previous talks, which have generally covered a broad collection of wavelength bands and technologies."
Alex received a prestigious Royal Academy of Engineering fellowship in 2025, for his project titled “Next generation of Energy-efficient Optical Regional and Data Centre Connections”. This will pioneer solutions to reduce the soaring energy demand of digital infrastructure. By combining bismuth-doped fibre amplifiers and optical frequency combs, the research aims to cut optical network power consumption by 30–50% per bit while enabling transmission capacities beyond 200 Tb/s.
Alex describes this as the next chapter of the work he began with TRANSNET. Under TRANSNET, he gained the environment, systems perspective and collaborations needed to move beyond considering an amplifier as a standalone device and instead ask what it changes at the system and network level: capacity, reach, energy consumption and complexity.
"That perspective directly shaped my Royal Academy of Engineering Research Fellowship, where I am combining O-band BDFAs, optical frequency combs, and lower-complexity digital signal processing to develop energy-efficient coherent links for data-centre interconnect and regional networks."
Alex has been instrumental in achieving TRANSNET's mission, with his fellowship award further proving the value of his work and innovation. As the end of the programme approaches, we look forward to Alex's last ECOC with us and to all he does next!