Active synchronization and modulation of fiber lasers with a graphene electro-optic modulator

We report the synchronization of two actively Q-switched fiber lasers operating at 1.5 mu m and 2 mu m with a shared broadband graphene electro-optic modulator. Two graphene monolayer sheets separated with a high-k HfO2 dielectric layer are configured to enable broadband light modulation. The graphene electro-optic modulator is shared by two optical fiber laser cavities (i.e., an erbiumdoped fiber laser cavity and a thulium/holmium-codoped fiber laser cavity) to actively Q-switch the two lasers, resulting in stable synchronized pulses at 1.5 mu m and 2 mu m with a repetition rate ranging from 46 kHz to 56 kHz. (C) 2018 Optical Society of America