Performance enhancement via XPM suppression of a linear all-PM mode-locked fiber oscillator.

Abstract

We demonstrate the strong performance enhancement of an all-polarization-maintaining mode-locked fiber oscillator using a linear self-stabilized fiber interferometer via the suppression of the cross-phase modulation (XPM). Numerical simulations reveal that XPM significantly affects the saturable absorber dynamics resulting in strong distortions of the mode-locked steady-states and output pulse quality. For experimental verification, we construct an oscillator with XPM suppression, employing an intra-cavity YVO4 crystal to obtain a differential walk-off effect and compare its characteristics with a reference oscillator in a standard configuration. It is shown, that the XPM suppression not only lowers the mode-locking threshold by more than 45% but further results in improved pulse quality at the output ports and reduced nonlinear loss in the artificial saturable absorber.