Real-time characterization of spectral instabilities in a mode-locked fibre laser exhibiting soliton-similariton dynamics

Thibaut Sylvestre,Christophe Finot,Piotr Ryczkowski,Coraline Lapre,Göery Genty,Fanchao Meng,Cyril Billet,John M Dudley

doi:10.1038/s41598-019-50022-5

Abstract

The study of dissipative solitons in mode-locked lasers reveals a rich landscape of interaction dynamics resulting from the interplay of nonlinearity, dispersion and dissipation. Here, we characterize a range of instabilities in a dissipative soliton fibre laser in a regime where both conventional soliton and similariton propagation play significant roles in the intracavity pulse shaping. Specifically, we use the Dispersive Fourier Transform technique to perform real-time spectral measurements of buildup dynamics from noise to the generation of stable single pulses, phase evolution dynamics of bound state “similariton molecules”, and several examples of intermittent instability and explosion dynamics. These results show that the instabilities previously seen in other classes of passively mode-locked fibre lasers are also observed in the presence of strong nonlinear attraction of similariton evolution in an optical fibre amplifier.

Highlights

Within three years of the first laser operation in 1960, ultrashort pulses were being generated by the mechanism universally known as mode-locking[1]
Our experiments studied the dynamics of an Er-doped fibre (EDF) amplifier based ring laser producing pulses centred on ~1555 nm with a repetition rate of 9.50 MHz
We reported what we believe to be a previously-unobserved regime of operation associated with the intermittent appearance of short-lived stable single pulses within a phase of otherwise chaotic explosion-like dynamics

Summary

Introduction

Within three years of the first laser operation in 1960, ultrashort pulses were being generated by the mechanism universally known as mode-locking[1]. An important technique of this kind is the dispersive Fourier transform (DFT) for real-time spectral characterization, and it was its application to isolate filtered long wavelength “rogue wave” fluctuations in a supercontinuum that highlighted the potential of real time measurements in nonlinear fibre optics[5]. This work was significant in revealing the internal dynamics of soliton “molecules,” bound states of interacting pulses that exist in dissipative systems[19,20,21]. These results subsequently motivated many additional experiments using real-time techniques to characterize instabilities in mode-locked lasers, and fibre lasers where a wide range of different dynamics can be observed depending on the intracavity group velocity dispersion (GVD) map[22]

Methods

Results

Conclusion