Random distributed multi-pulse dynamics in mode-locked regimes of a highly nonlinear fiber ring laser

Abstract

The generation and transition dynamics of random distributed multi-pulse are studied numerically and experimentally in the mode-locked fiber laser. The influence of various cavity parameters on the generation of multi-pulse in the fiber laser is investigated and the random distributed multi-pulse with delta-like characteristics in the autocorrelation trace is generated numerically. The results show that the highly nonlinear fiber can significantly enhance the nonlinear effect in the cavity to effectively and quickly enter the multi-pulse region. By adding the highly nonlinear fiber to the fiber laser in the experiment, the random distributed multi-pulse is generated under appropriate polarization state and pump power, which is consistent with the simulation results. The transition dynamics of the variation in the number of pulses during the formation process of the random distributed multi-pulse is studied by using the time-stretch dispersive Fourier transform technology. The random distributed multi-pulse combines the advantages of both pulse and chaotic signals, with a higher peak-to-peak value and random distribution in the time interval between pulses. Our work provides fundamental insights into the evolution and dynamic behavior in random distributed multi-pulse and broaden its potential applications in the correlation fiber loop ring down sensing.