Modeling of Tm–Ho codoped fiber saturable absorber based passive Q-switching of an Er-doped fiber laser

A theoretical model concerning the Tm–Ho codoped fiber saturable absorber based passive Q-switching of an Er-doped fiber laser is established. Comparison with the Tm-doped fiber saturable absorber is described and discussed. Numerical results indicate that, compared with a Tm-doped fiber saturable absorber, the Tm–Ho codoped fiber saturable absorber shortens the lifetime of the 3F4 energy level and improves the operation of the laser system.