Highly efficient reduced graphene oxide mode-locked Nd：GGG laser

We report, for the first time to our knowledge, a diode-end-pumped passively mode-locked(ML) Nd-doped gadolinium gallium garnet laser based on a chemically reduced graphene oxide(RGO) saturable absorber mirror. The ML laser gives a pulse duration of 15.1 ps under the maximum average output power of 1.44 W, corresponding to a slope efficiency of 21.1%. The single-pulse energy and peak power are 21.6 n J and 1.43 k W, respectively. The results indicate that our RGO saturable absorber has promising prospects for applications in high-power and high-efficiency ultrafast lasers.