Explosion induced rogue waves and chaotic multi-pulsing in a passively mode-locked all-normal dispersion fiber laser

Abstract

In this work, an experimental study of non-stationary pulse dynamics consisting of explosion events and chaotic multi-pulsing from an all-normal dispersion Yb-fiber laser operating in noise-like pulse (NLP) state have been reported. During explosion in NLP state, which resembled soliton explosion, dispersive Fourier transform measurements revealed large, intermittent amplitude fluctuations in the real-time spectrum indicative of rogue waves. The fluctuations either appeared randomly at the lasing wavelength within the Yb-gain spectra or at the frequency downshifted Raman Stokes wavelength. It was also observed that such fluctuation at the Raman wavelength could even exceed the amplitude of the spectral components at the main lasing wavelength. With suitable adjustments to polarization controllers, the laser operation could be switched to chaotic multi-pulsing state where the acquisition of a large number of consecutive roundtrips revealed inter-pulse motion with unique trajectories occurring over millisecond time scales.

Paths from stationary to chaos in passively mode-locked fiber lasers: research progress of soliton pulsations and soliton explosions

“…The solid green line in figure 10(b) presents that the pulse energy of soliton explosions will increase significantly as an explosion occurs, creating a powerful condition for the formation of optical rogue waves (ORWs) with high amplitude [178]. Real-time shot-to-shot spectrum evolution of soliton explosions recorded by the DFT technique shows that there are few large fluctuations in the event of Raman Stokes sideband explosions, evidencing the existence of ORWs [171]. Some reports also prove that the collision of breathing solitons will significantly enhance the amplitude of ORWs in bidirectional SWCNTs passively mode-locked fiber lasers [179,180].…”

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

“…Beyond soliton operation, a common regime of passively mode-locked fiber lasers is NLP generation [35][36][37][38][39][40][41][42][43]. An NLP is a large (∼ns) bunch of radiation, which contains a fine inner structure at sub-ps scale.…”

“…Fast scope measurements can also be used to study the dynamics in the spectral domain (spectral mapping, also called real-time spectroscopy). Single-shot optical spectra can be obtained from the time-domain signal through the dispersive Fourier transform (DFT), which in practice simply consists of using a long dispersive fiber before detection: the pulse is stretched temporally until its shape no longer relates to the original temporal waveform, but instead is an image of its optical spectrum [39,40,43,45]. Such measurements allow building the sequence of the single-shot spectra over successive round-trips and analyzing their evolution, in much the same way as in the time domain.…”

“…Among those regimes, one finds, for example, various types of pulsating instabilities [31], soliton explosions [32], multiple solitons dynamics [33,34], and noise-like pulsing [35][36][37][38][39][40][41][42][43]. A frequently related subject is the quest for extreme-intensity optical events (ORWs) [25,[39][40][41][42][43][44][45]. However, given the extreme diversity and richness of those complex regimes, most of which are still puzzling researchers, the subject can hardly be reduced to a few keywords.…”

Spatio-spectral dynamics of soliton pulsation with breathing behavior in the anomalous dispersion fiber laser

“…A variety of soliton transient dynamics was observed in passively mode-locked fiber lasers adopting the DFT technique: the build-up of dissipative soliton pulsation, [14] successive soliton explosion, [15] explosion induced rogue waves. [16] Breathing behavior of dissipative soliton pulsation, [17][18][19] multiple soliton pulsation, [20,21] dissipative soliton explosion [22] and the pulsating soliton molecule [23] are observed in the normal dispersion NPR mode-locked fiber laser by the DFT. In the anomalous dispersion region, the soliton pulsation with chaotic behavior [24] and the soliton pulsation sideband characteristics [12] are also studied.…”