Continuous-wave and chemical vapor deposition graphene-based passively Q-switched Er:Y2O3 ceramic lasers at 2.7 μm

We report on 976-nm diode-pumped Er:Y2O3 ceramic lasers in continuous-wave and passively Q-switched regimes. The maximum output power of continuous-wave laser operation is about 0.78 W with slope efficiency of about 11.8% at 2.7 mu m. Passively Q-switched Er: Y2O3 ceramic laser operation with chemical vapor deposition (CVD) graphene as the saturable absorber is also demonstrated for the first time, to our knowledge. Using a monolayer CVD graphene, the achieved shortest pulse width is about 408 ns, while the shortest pulse width reduces to about 296 ns with pulse energy of 2.59 mu J and peak power of 8.77 W by using a three-layer CVD graphene. The results reveal that graphene is a very promising saturable absorber operating in the middle infrared spectral region. (C) 2018 Optical Society of America