Q-switched mode-locking of an erbium-doped fiber laser incorporating a graphene oxide-deposited D-shaped fiber

We experimentally demonstrate a passively Q-switched, mode-locked fiber laser incorporating a graphene oxide (GO)-deposited side-polished D-shaped fiber. Using both features of nonlinear saturable absorption and large polarization dependence loss of the GO-deposited side-polished D-shaped fiber, stable Q-switched mode-locked pulses are readily obtained from an erbium fiber ring cavity.