Soliton formation from a noise-like pulse during extreme events in a fibre ring laser

Abstract

We study experimentally the interactions between soliton and noise-like pulse (NLP) components in a mode-locked fibre ring laser operating in a hybrid soliton-NLP regime. For proper polarization adjustments, one NLP and multiple packets of solitons coexist in the cavity, at 1530 nm and 1558 nm, respectively. By examining time-domain sequences measured using a 16 GHz real-time oscilloscope, we unveil the process of soliton genesis: they are produced during extreme-intensity episodes affecting the NLP. These extreme events can emerge sporadically, appear in small groups or even form quasi-periodic sequences. Once formed, the wavelength-shifted soliton packet drifts away from the NLP in the dispersive cavity, and eventually vanishes after a variable lifetime. Evidence of the inverse process, through which NLP formation is occasionally seeded by an extreme-intensity event affecting a bunch of solitons, is also provided. The quasi-stationary dynamics described here constitutes an impressive illustration of the connections and interactions between NLPs, extreme events and solitons in passively mode-locked fibre lasers.

Complex dynamics of passively mode-locked fiber lasers with strict polarization control

“…Finally, another kind of complex dynamics, involving quasi-periodic energy fluctuations, wavelength shifts, extreme-intensity events, the formation of solitons in a NLP, and even NLP to solitons conversion, was observed experimentally and described in a ring laser cavity (Fig. 1a)) [57,58]. In this case, measurements were performed using a 16 GHz fast oscilloscope.…”

Principles of operation of a passively mode-locked fiber ring laser and 3D mapping of ultra-short pulses

“…It is important to remark that the complete identification and characterization of this regime of NLP and bunches of solitons was presented in [29]. Besides, the pulse dynamics of this regime is analyzed in [36]. In contrast, the object of this work is only to illustrate an experimental 3D mapping measurement.…”

“…Different behaviors and interactions of pulses have been investigated, which encompass different types of pulses: noise-like pulses (NLPs) [6,25,26,28], dissipative solitons [30,31], spiny solitons [32], among others. A recently developed tool, which is useful in ML-FL researches, is a 3D mapping technique of the pulse temporal profile, which helps analyzing pulse dynamics [31,[33][34][35][36].…”

Experimental study of non-stationary operation of a dual-wavelength passively mode-locked fibre ring laser

“…It is important to remark that, due to the resolution and bandwidth limitations of the fast oscilloscope, the amplitude of the envelope depends on the distribution of the solitons in the bunch, in particular on their spacing: indeed, the envelope amplitude will represent the energy of single solitons only if their spacing is large enough; if they are closely packed, the envelope reproduces the energy of multiple solitons. Another intriguing dynamics is one that involves the generation of a bunch of solitons by extremely high events in a NLP, first experimentally evidenced in [31]. NLPs [32][33][34][35][36] are ∼ns-long packets containing hundreds or thousands of chaotic sub-pulses and present a broad optical spectrum [37,38].…”