Rogue waves in a linear cavity Yb-fiber laser through spectral filtering induced pulse instability.

In this Letter, experimental observation of dissipative rogue waves (DRWs) due to spectral filtering induced pulse instabilities in a mode-locked ytterbium (Yb) fiber laser has been presented. A semiconductor saturable absorber mirror was used to mode-lock the linear cavity laser and a chirped fiber Bragg grating (CFBG) was used for dispersion management, which also acted as a spectral filter and output coupler. Under stable conditions, the cavity delivered dispersion managed dissipative solitons of 447 fs duration and 0.69 nJ pulse energy at 10.19 MHz repetition rate with uniform intensity distribution over a long time span. As the spectral width increased with pump power, random intensity fluctuations were observed in the pulse train due to the filtering effect of the CFBG. Employing a dispersive Fourier transform by stretching the output pulse train in time allowed the existence of DRWs more than 4 times stronger than the significant wave height to be observed. Further increments of pump power led to a stable multi-pulsing state.