Broadband Tunable Passively Q-Switched Erbium-Doped ZBLAN Fiber Laser Using Fe3O4-Nanoparticle Saturable Absorber

Abstract

Featured Application: Spectroscopic, sensing, material processing, and laser surgery. We experimentally demonstrate a passively Q-switched wavelength tunable 2.8 μm erbium-doped fiber laser. Fe3O4 nanoparticles deposited on a gold mirror are used as a saturable absorber (SA). Stable Q-switched pulses within the tunable range of 2710–2810 nm are obtained. At the wavelength of 2760 nm, a maximum Q-switched output power of 188 mW is achieved with a repetition rate of 115.8 kHz and a pulse width of 1.3 μs. The corresponding pulse energy is 1.68 μJ. This demonstration shows the ability of Fe3O4 to function as a broadband mid-infrared SA.