Suppression of self-pulsations in DFB fiber lasers

Summary form only given. The origin of self-pulsations in Er-doped distributed-feedback (DFB) fiber lasers is related to ion clustering at high erbium concentrations. The clusters act as saturable absorbers with switching time much shorter than the population inversion recovery time and can eventually result in spiking behavior of the laser. Reducing the erbium concentration while still providing enough gain in a short cavity DFB fiber laser can be achieved by Yb co-doping which increases the pumping efficiency. Stabilization of the laser against self-pulsations can also be accomplished by resonant pumping or co-pumping directly into the metastable Er-ion state, damping down the oscillations of the population inversion.