MnO2 nanosheets as saturable absorbers for a Q-switched fiber laser

Manganese oxide nanosheets (MnO 2 NSs) with two-dimensional formation and typically ultrathin thickness have gained a great deal of attention due to their excellent physical and chemical properties. However, the potential capability of MnO 2 NSs in laser application has been rarely explored. Here, we first report the MnO 2 NSs as the saturable absorber (SA) for generating Q-switched pulsed laser. The MnO 2 NSs–based SA not only shows a broadband absorption, but also possesses nonlinear saturable absorption feature. By integrating the MnO 2 NSs-SA into an erbium-doped fiber laser cavity, a stable passively Q-switched operation at central wavelength of ∼1558 nm was realized with a threshold pump power of 220 mW, and 1.26 μs pulse width with a repetition rate of 92.35 kHz was obtained. Our results indicate that the MnO 2 NSs can serve as promising candidates for constructing optical pulsed lasers.