A femtosecond thulium holmium co-doped fiber laser based on graphene oxide evanescent filed interaction

We demonstrate an all fiberized, passively mode-locked thulium holmium co-doped fiber laser operating at a wavelength of ~1.95 μm using the graphene-oxide evanescent field interaction. A temporal pulse width of ~590 fs is experimentally obtained at 33.25 MHz.