Ferroferric-oxide nanoparticle based Q-switcher for a 1 μm region

Transition metal oxides (TMOs) have been successfully demonstrated as Q-switchers for pulsed fiber lasers. In this work, the ferroferric-oxide (Fe3O4) nanoparticles are synthesized via chemical co-precipitation. Filmy Fe3O4/polyvinyl alcohol (PVA) is adopted as the Q-switcher in a 1 μm region. The Fe3O4/PVA film has the modulation depth of 7.8% and saturable intensity of 71.32 MW/cm2, respectively. By incorporating the Fe3O4/PVA film into Yb-doped fiber laser (YDF) cavity as a saturable absorber (SA), the stable Q-switching operation is obtained in 77-157 mW pump power range. At the pump power of 147 mW, the Q-switched YDF laser emits stable laser pulses with the maximum single pulse energy of 50.35 nJ and shortest pulse duration of 1.63 μs. The experimental results indicate that the zero-dimensional Fe3O4 nanoparticles have a bright prospect for nonlinear optics applications.