High-peak-power subnanosecond passively Q-switched ytterbium-doped fiber laser

A passively Q-switched ytterbium doped fiber laser has been demonstrated with a Cr(4+):yttrium aluminum garnet saturable absorber and distributed stimulated Brillouin scattering. A linearly polarized output with approximately 375 kW peak power and a pulse duration as short as 490 ps have been obtained. A theoretical model is developed to simulate passive Q switching with the stimulated Brillouin scattering, which shows good agreement with the experiment.