Xinning Huang’s research team’s report demonstrates a dual-wavelength stable Q-switched Er-doped fiber (EDF) laser with a reduced graphene oxide (rGO)-based saturable absorber. The rGO is prepared by depositing the graphene oxide on fluorine mica (FM) using a thermal reduction method. The modulation depth and saturable intensity of rGO/FM are measured to be 5.8% and 73.6 MW cm(-2). By employing the rGO/FM film in the EDF laser cavity, stable dual-wavelength Q-switching operation is achieved. The two wavelength peaks locate at 1531.84 nm and 1558.14 nm. The shortest pulse duration is 1.83 mu s. The maximum output power is measured to be 14.65 mW, corresponding to the maximum single pulse energy of 154.34 nJ. The experimental results evidently show that the rGO is a promising type of nonlinear material.

（Original research article "Laser Physics Vol. 29, Issue 6, 065101 (2019) https://iopscience.iop.org/article/10.1088/1555-6611/ab0d12 "）