Polarisation dynamics of mode-locked fibre lasers

This presentation highlights recent advances in the polarisation dynamics of mode-locked fibre lasers and their application to dual-comb Mueller polarimetry. Using erbium-doped fibre lasers as a model platform, the author outlines his group’s contributions to understanding a broad range of vector-soliton behaviours—including polarisation attractors, soliton rain, and harmonic mode-locking—within a unified vector framework. Two recently identified synchronisation mechanisms are highlighted: slow dissipative-soliton breathing arising from desynchronisation between orthogonal polarisation states, and vector subharmonic entrainment induced by a weak injected signal with a time-varying state of polarisation. The presentation then shows how the intrinsic polarisation diversity of a single-cavity dual-comb laser can enable compact Mueller polarimetry without external polarisation optics. This approach supports simultaneous fibre Bragg grating measurements of strain and torsion, as well as material classification for polarimetric LiDAR.

Biography

Sergey Sergeyev is an Associate Professorial Research Fellow at the Aston Institute of Photonic Technologies, Aston University, and an internationally recognised researcher in nonlinear photonics. His work spans polarisation dynamics in mode-locked fibre lasers, optical frequency combs, dual-comb spectroscopy, Mueller-matrix polarimetry, and fibre-optic sensing. His key contributions include vector solitons, spiral attractors, vector resonance multimode instability, bright–dark rogue waves, acoustic resonance-driven harmonic mode locking, polarisation-driven dissipative-soliton breathing, and vector subharmonic entrainment.

More recently, he introduced single-cavity dual-comb Mueller polarimetry for material-aware LiDAR and simultaneous fibre Bragg grating strain and torsion sensing. His previous academic and industrial career has included appointments in Belarus, Sweden, Ireland, and the UK at Belarusian State University, Ericsson, Acreo, KTH, and Waterford Institute of Technology. He joined Aston University as a Marie Curie Senior Research Fellow in 2010 and has held his current position since 2018. He has published more than 230 peer-reviewed papers, co-edited a CRC Press monograph, contributed to patented optical technologies, and led UK and European programmes worth over £7 million. His Royal Academy of Engineering and Royal Society Industry Fellowships advance polarimetric LiDAR for crop monitoring and fibre-optic sensing for wind-turbine structural health monitoring.