High-peak-power nanosecond pulse generation by stimulated Brillouin scattering pulse compression in a seeded Yb-doped fiber amplifier

Brillouin scattering-induced rogue waves in self-pulsing fiber lasers

We report the experimental observation of extreme instabilities in a self-pulsing fiber laser under the influence of stimulated Brillouin scattering (SBS). Specifically, we observe temporally localized structures with high intensities that can be referred to as rogue events through their statistical behaviour with highly-skewed intensity distributions. The emergence of these SBS-induced rogue waves is attributed to the interplay between laser operation and resonant Stokes orders. As this behaviour is not accounted for by existing models, we also present numerical simulations showing that such instabilities can be observed in chaotic laser operation. This study opens up new possibilities towards harnessing extreme events in highly-dissipative systems through adapted laser cavity configurations.

Dynamics of stimulated Brillouin scattering in optical fibers without external feedback induced by frequency detuning from resonance

In optical fibers, stimulated Brillouin scattering are usually investigated in the regime of resonance. Whereas, in this paper, we discover for the first time that, without participation of Kerr effect, frequency detuning from resonance can give rise to rich dynamical behaviors for stimulated Brillouin scattering in optical fibers. Distinct from the dynamics presented in the conventional Brillouin lasers, this kind of phenomena does not need external feedback at all but also presents a variety of classifiable dynamical features for continuous-wave pumping, including steady state, periodic state and chaos. We analyze that the main mechanisms responsible for these dynamical behaviors include the transient response of acoustic wave, relaxation oscillation, frequency mixing effect induced by three-wave coherent coupling and Brillouin gain-induced group velocity change. Moreover, it should be pointed that it is the first time to discover in theory that there exists the frequency mixing effect induced by three-wave coherent coupling in the regime of non-resonance for the stimulated Brillouin scattering process, which as a consequence determines the periodic state.

High-power passively Q-switched thulium fiber laser with distributed stimulated Brillouin scattering

We report a novel passively Q-switched 2 μm Tm(3+) fiber laser simply by distributed stimulated Brillouin scattering with an all-fiber configuration. The maximum output power is 2.49 W with an optical-to-optical slope efficiency of 12%, and the laser wavelength is centered at ~1991 nm with a spectral width of >10 nm. The single pulse energy can be over 50 μJ with a pulse width of about 20 ns, and the pulse repetition rate can be tuned from several kilohertz to tens of kilohertz by changing the pump power. To the best of our knowledge, this is the highest-average-power passively Q-switched 2 μm Tm(3+) fiber laser in the nanosecond regime.