Cobalt-doped zinc oxide nanorods as saturable absorber in passively q-switched fiber laser

All-fiber passively Q-switched fiber lasers have been demonstrated by using cobalt-doped zinc oxide (Co-ZnO) nanorods, which is embedded into a polyvinyl alcohol (PVA) film as a passive Q-switcher. The SAs has been fabricated by mixing nanorods Co-ZnO solution with PVA solution and dried it in a room temperature. It is incorporated into an Erbium-doped fiber laser (EDFL) cavity to generate a Q-switching pulses train operating at 1559.0 nm. The repetition rates of the laser can be tuned from 56.1 kHz to 79.4 kHz as the power of the pump is varied from 30.5 mW to 109.4 mW. Concurrently, the pulse width decreased from 7.30 µs to 4.62 µs. The laser produces maximum pulse energy of 142 nJ.