Nonlinear interference between solitons and nonstationary dispersive waves in a passively mode-locked fiber laser

Abstract

We numerically investigated the interaction of a soliton with nonstationary dispersive waves as well as the soliton interaction induced by them, in a fiber ring laser mode locked by a nonlinear polarization rotation technique. In low-loss mode-locked states, a resonant frequency shifting effect and two time-jittering motions of solitons are found during the interaction. An analysis reveals that an indirect phase-matching interference between a pulsed dispersive wave and a soliton upon cross-phase modulation breaks the conservation of soliton momentum, while the subsequent soliton reconstruction leads to a recovery of the conservation. The interference mechanism, together with the conservation of soliton momentum, accounts for some basic behaviors of soliton laser dynamics.