A Yb-doped self-sweeping fiber laser with intensity dynamics control

A Yb-doped sigma-cavity self-sweeping fiber laser has been developed. It was demonstrated that the intensity dynamics can be controlled via changing the radiation direction in the ring part of the cavity. A continuous-wave (CW) self-sweeping operation was obtained for the case of co-propagating pump and generation radiation. In turn, for the configuration with counter-propagating pump and generation radiation a transition from CW to pulsed intensity dynamics with pump power increase was demonstrated for the first time. The generation occurred near the central wavelengths of 1082–1083 nm with the sweeping range varying from 0.1 to 0.5 nm for co– and counter-propagating pump and generation radiation, respectively. It was demonstrated that the intensity dynamics retain the properties typical for CW self-sweeping even in the case of μs-long pulses generation. New criteria for the characterization of the self-sweeping fiber lasers intensity dynamics were proposed. The results obtained can be used for development and characterization of self-sweeping lasers.