Dissipative Soliton Generation in a Phase-Biased All-PM Fiber Oscillator in the Normal-Dispersion Regime

We numerically and experimentally demonstrate a phase-biased fiber oscillator with all-polarization-maintaining (all-PM) fibers. Through theoretical analysis, it is demonstrated that incorporating a non-reciprocal phase shifter improves the self-starting capability of the designed fiber laser. Moreover, the phase shifter in the all-PM laser configuration helps boost the repetition rate and further enhances the environmental stability. Numerical simulations are conducted for the proposed fiber laser operating in the normal-dispersion regime to investigate the spectral and temporal characteristics and the build-up dynamics. Experimentally, by manipulating the separation of the intra-cavity grating pair for dispersion compensation, this simple and novel Ytterbium-doped fiber laser delivers ultrashort pulses featuring a pulse duration of 1.81 ps, operating at a repetition rate of 44.4 MHz in the 1030 nm band. The delivered pulses are compressed externally using a grating pair, achieving a minimum pulse duration of 174 fs. We believe the proposed fiber oscillator provides a robust pulsed light source for numerous optical applications such as micromachining or optical frequency comb generation.