An intracavity resonant Fabry-Perot saturable absorber (R-FPSA) induces
modelocking in a laser such as a fiber laser. An optical limiter such as
a two photon absorber (TPA) can be used in conjunction with the R-FPSA,
so that Q-switching is inhibited, resulting in laser output that is cw
modelocked. By using both an R-FPSA and a TPA, the Q-switched modelocked
behavior of a fiber laser is observed to evolve into cw modelocking.