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 μm. 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 μJ 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.