Passive Q-switched erbium-doped fiber laser based on graphene saturable absorber

A Q-switched Er-doped fiber laser is demonstrated using graphene as saturable absorber (SA). The graphene SA is fabricated to the fiber end using optically driven deposition method. As we increase the pump power from 128 mW to 380 mW, the pulse repetition rate of the Q-switched fiber laser changed from 23 to 67 KHz and the pulse width varies from 5.2 to 0.9μs. A repetition rate of 67 KHz is obtained at the maximum pump power of 380 mW, with pulse width and pulse energy of 0.9μs and 179 nJ, respectively.