Rogue waves in mode-locked fiber lasers

We report on the theoretical observation of optical rogue waves in a dissipative system, namely, a mode-locked fiber laser. These rogue waves are pulses of huge peak power which may chaotically appear in the laser. They exist in the normal dispersion regime and exhibit peak powers exceeding those of stable dissipative solitons by a factor of 13. Their height exceeds the so-called significant wave height by a factor of 6. The peak power of the rogue waves can be changed by varying the laser gain. These rogue waves arise from noise by a peculiar nonlinear focusing process of the intracavity light in this dissipative system without requiring any specific initial conditions. Moreover, we identify the crucial effect of gain saturation on the focusing process and, consequently, on the peak amplitude of rogue waves. Similar to rogue events in the ocean, the laser rogue pulses are also accompanied by holes which are moving dark solitons.