Pulse formation mechanisms switching in hybrid mode-locked fiber laser

TL;DR

This paper investigates the mechanisms of pulse formation in hybrid mode-locked fiber lasers, revealing the dynamic switching among different mode-locking techniques through experiments and simulations, and advancing understanding for multi-wavelength laser development.

Contribution

It introduces a novel simulation method for filtered gain spectrum and explores the switching of pulse formation mechanisms in hybrid mode-locked fiber lasers.

Findings

Identified three pulse formation mechanisms: SA-dominated, NPE-dominated, and co-domination switching.

Proposed a new simulation approach using customized filtering for gain spectrum.

Deepened understanding of hybrid mode-locking dynamics and potential for multi-wavelength lasers.

Abstract

Hybrid mode-locking has been widely used in enhancing pulse quality, however how the hybrid two mode-locking techniques work remains unclear. In this paper, we experimentally investigate three pulse formation mechanisms in saturable absorbers (SA) and nonlinear polarization evolution (NPE) passively hybrid mode-locked fiber laser, which are SA-dominated, NPE-dominated, and SA-NPE co-domination switching. Clarified the exists dynamic competition and cooperation among the mode-locking techniques. For the first time, the method of simulating filtered gain spectrum with customized filtering is proposed, and the switching of pulse formation mechanisms is numerically investigated using the coupled Ginzburg-Landau equations. Our results deepen the understanding of hybrid mode-locked fiber lasers and provided a foundation for multi-wavelength mode-locked lasers with different mode-locking techniques in a single cavity.