Bifurcations and multiple-period soliton pulsations in a passively mode-locked fiber laser.

We observed, numerically and experimentally, multiple-period pulsations of the soliton parameters in a passively mode-locked fiber laser. Pulsation periods can vary from a few to hundreds of round trips. Short and long period pulsations can appear in combination. The new periods in the soliton modulation appear at bifurcation points related to certain values of the cavity parameters.