Aluminum oxide nanoparticles as saturable absorber for C-band passively Q-switched fiber laser

We report on aluminum oxide nanoparticles (Al2O3 NPs) as a saturable absorber (SA) for passively Q-switched erbium-doped fiber laser (EDFL) operating at a wavelength of 1560.6 nm within the C-band region. A thin film of Al2O3-SA was prepared using polyvinyl alcohol (PVA) as a host polymer. Very stable pulses with a 57.8 KHz repetition rate and 5.6 mu s pulse width at a threshold pump power of 158 mW were obtained. A 2.8 mu s pulse width, 81 kHz pulse repetition rate, with maximum pulse energy of 56.7 nJ at a diode pump power of 330 mW were recorded. To the best of the authors' knowledge, this is the first time that a Al2O3-based SA has been used to generate a Q-switched EDFL. (C) 2017 Optical Society of America