Stable self-pulsing regime in a Brillouin ring fiber laser cavity

Abstract

This study reports that when solving by full integration a set of coupled ordinary differential equations that describe the spatial evolution of the guided pump and Stokes powers caused by stimulated Brillouin scattering in the regime of pump depletion, a structure of regular pulses emerge from the output of a Brillouin laser cavity characterized as a stable self-pulsing regime. The dependence of this self-pulsing mechanism on the laser cavity length, the coupling factor, and the pump power is investigated revealing the existence of three regimes: no lasing, continuous, and self-pulsing. When compared to records in the scientific literature, this is the first time, to the best of the author’s knowledge, that a stable self-pulsing regime is reported theoretically. Furthermore, we also demonstrated the pumping depletion during the formation of the self-pulsing regime. These results provide not only a better understanding of the dynamics of self-pulsing regimes in a fiber laser cavity but also the possibility of unlocking the mechanisms responsible for the formation of stable pulse trains in a Brillouin fiber-ring laser.

Dynamic Interplay Between Kerr Combs and Brillouin Lasing in Fiber Cavities

“…Note that multimode instabilities in Brillouin lasers have been extensively investigated, depending on the cavity parameters. They can lead to random fluctuations of the laser output, [24][25][26] or even a form of mode-locking [27][28][29][30][31] in low finesse cavities (weak feedback coupling), which was not observed here.…”

Sub-megahertz compact self-pulsed Raman laser

“…Self-pulsed Brillouin-Raman distributed feedback fiber laser with pulse width of 25 ns and repetition rate of 7 MHz operating at 1119 nm has been demonstrated [21]. And mathematical model has been proposed for the Brillouin ring fiber laser to analyse the self-pulsing regime [22]. However, the output power is low and the spectral range is narrow.…”