Unveiling temporal correlations characteristic to phase transition in the intensity of a fibre laser radiation

TL;DR

This paper employs advanced time-series analysis tools to identify and characterize temporal correlations during the phase transition from laminar to turbulent regimes in a fibre laser, revealing coherent structures and strong correlations.

Contribution

It introduces the application of ordinal analysis and horizontal visibility graphs to laser intensity data, uncovering temporal correlations during the transition to turbulence.

Findings

Detection of temporal correlations during the transition

Identification of coherent structures with specific time-scales

Strong correlations in pulse timing and intensities

Abstract

We use advanced statistical tools of time-series analysis to characterize the dynamical complexity of the transition to optical wave turbulence in a fibre laser. Ordinal analysis and the horizontal visibility graph applied to the experimentally measured laser output intensity reveal the presence of temporal correlations during the transition from the laminar to the turbulent lasing regimes. Both methods unveil coherent structures with well defined time-scales and strong correlations both, in the timing of the laser pulses and in their peak intensities. Our approach is generic and may be used in other complex systems that undergo similar transitions involving the generation of extreme fluctuations.