Correlations Preceding High-Intensity Events in the Chaotic Dynamics of a Raman Fiber Laser.

Andrés Aragoneses,Yingqi Ding

doi:10.3390/e21020151

Andrés Aragoneses, Yingqi Ding

Open Access

https://doi.org/10.3390/e21020151

Copy DOI

Abstract

We study the time series of the output intensity of a Raman fiber laser with an ordinal patterns analysis in the laminar-turbulent transition. We look for signatures among consecutive events that indicate when the system changes from triggering low-intensity to high-intensity events. We set two thresholds, a low one and a high one, to distinguish between low intensity versus high-intensity events. We find that when the time series is performing low-intensity events (below the low threshold), it shows some preferred temporal patterns before triggering high-intensity events (above a high threshold). The preferred temporal patterns remain the same all through the pump current range studied, even though two clearly different dynamical regimes are covered (laminar regime for low pump currents and turbulent regime for high pump currents). We also find that the turbulent regime shows clearer signatures of determinism than the laminar regime.

Highlights

Besides the innumerable technological applications, lasers are a fascinating tool for the study and characterization of nonlinear dynamics in a laboratory-controlled manner [1]
We analyze the output intensity of a quasi-cw Raman fiber laser formed of km of normal dispersion fiber
Two different regimes can be distinguished in the output power of the Raman fiber laser as we vary the pump current

Summary

Introduction

Besides the innumerable technological applications, lasers are a fascinating tool for the study and characterization of nonlinear dynamics in a laboratory-controlled manner [1]. The light amplification of these lasers involves nonlinear interactions of millions of longitudinal cavity modes. This leads to a highly complex dynamics in the output intensity of the laser. In previous studies [13,14], it was found that behind the high complexity of the time series of the output intensity of the fiber laser, the system showed some structure that could be unveiled using an ordinal patterns analysis. In [14], through a simple mathematical model and an ordinal patterns analysis, it was seen that the transition was related to internal frequencies of the dynamics

Objectives

Methods

Results

Conclusion