Optimizing stable mode-locked operation of Yb-doped fiber laser

We report on a novel simple configuration of an Yb-doped fiber laser cavity comprising only Yb-doped fiber and a saturable absorber element. Numerical results show that stable mode-locked operation does exist in such a laser cavity in limited range of parameters. The conditions to obtain stable pulses are investigated as a function of the Yb-fiber bandwidth, length, and gain coefficient. The temporal and spectral behavior of the femtosecond pulses are also studied for different input parameters. The instability dynamics of the mode-locked pulse is also elucidated.