Generation of spatio-temporal extreme events in noise-like pulses NPE mode-locked fibre laser.

S V Smirnov,D V Churkin,O A Gorbunov,S Sugavanam

doi:10.1364/oe.25.023122

S V Smirnov, D V Churkin + Show 2 more

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https://doi.org/10.1364/oe.25.023122

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Journal: Optics Express	Publication Date: Sep 12, 2017
Citations: 17	License type: cc-by

Affiliation: Novosibirsk State University, Aston University

Abstract

We experimentally study spatio-temporal generation of extreme events in the radiation of NPE mode-locked fibre laser generating noise-like pulses. We show that new pulses starts from high-intensity spatio-temporal structure which consist of mainly 3 subsequent pulses which are both separated over fast and slow evolution time. Statistical analysis of the noise-like pulse evolution over round-trips shows that the pulse width and intensity varies with a period of around 85 round-trips which does not change from pulse to pulse. The intensity probability density function has a heavy tail originated only from events of pulse formation.

Highlights

Fibre lasers mode-locked by nonlinear polarization evolution (NPE) are well known in physics and applications by a robust design and high performance output
NPE-mode-locked fibre lasers are characterized by a great variability of possible lasing regimes even in the case of singlepulse operation [1]
Experimental setup and basic laser properties We study a nonlinear polarization evolution (NPE) mode-locked laser made of the Er-doped active fibre (Er-DC) placed in the ring cavity together with a 1 km long normal-dispersion (ND) fibre (D = - 44ps/nm/km), polarization beam splitter (PBS) and polarization controllers (PC1 and PC2), Fig. 1

Summary

Introduction

Fibre lasers mode-locked by nonlinear polarization evolution (NPE) are well known in physics and applications by a robust design and high performance output. NPE-mode-locked fibre lasers are characterized by a great variability of possible lasing regimes even in the case of singlepulse operation (one pulse travelling in the cavity) [1]. NPE-mode-locked lasers are designed to operate in a regime of noise-like pulses. Recent studies suggests that mechanisms of coherence’s loss in noise-like pulses mode-locked laser include interplay of modulation instability, parametric instability, cascaded four-wave mixing [15]. The output performances of the laser could be optimized during laser’s operation by using an evolutionary algorithm that prescribes a set of cavity parameters entailing specific self-starting mode locking [16]. The noise-like pulses can be used for pumping supercontinuum sources [18, 19], for applications in ultra-high resolution optical coherence tomography [20]

Methods

Conclusion