Carboxyl graphene oxide solution saturable absorber for femtosecond mode-locked erbium-doped fiber laser
Lv Rui-dong1, Li Lu2, Wang Yong-gang1, †, Chen Zhen-dong1, Liu Si-cong1, Wang Xi3, Wang Jiang1, Li Yong-fang1
       

(color online) The nonlinear saturable absorption curve of SA and the corresponding fitting curve.