Subnanosecond and picosecond generation regimes of all-PM Yb-doped fiber lasermode-locked by NOLM

We demonstrated two stable pulsed operation regimes of all-polarization maintaining (PM) Yb-doped fiber laser oscillator with pulse duration of 640 and 85 ps. Nonlinear optical loop mirror (NOLM) was used for laser mode-locking. The first operation regime delivered high energy pulses of 5 nJ, and second regime delivered pulses of 0.7 nJ at a common repetition rate 5 MHz. The dynamics of the temporal and spectral parameters of laser pulses was studied using mathematical simulation based on numerical solution of the nonlinear Schrödinger equation. The simulation results showed that in stable regime with pulse duration of 85 ps the pulse could be compressed to 2 ps. (paper)