Dual-color Q-switched mode-locking in an Erbium-doped fiber laser

TL;DR

This paper investigates the generation mechanism of dual-color Q-switched mode-locking in an Erbium-doped fiber laser, revealing a bound-state-like spectral envelope and two pulse evolution patterns through theoretical and numerical analysis.

Contribution

It introduces the first observation of a bound-state-like spectral envelope in dual-color QML fiber lasers and explores its formation mechanism via coupled Ginzburg-Landau equations.

Findings

Discovery of a bound-state-like envelope in dual-color QML spectrum

Identification of two QML pulse evolution patterns

Numerical investigation of QML formation mechanisms

Abstract

Q-switched mode-locking (QML) has been widely observed in various lasers, but its generation mechanism in passive mode-locking remains unclear. In this paper, we build up a dual-color QML Erbium-doped fiber laser and find a bound-state-like envelope on the optical spectrum for the first time. Theoretically, the formation mechanism of QML is numerically investigated using the coupled Ginzburg-Landau equations. In addition, we demonstrated the existence of two QML pulse evolution patterns with gain or polarization state variations in simulation. Our results deepen the understanding of QML pulses in mode-locked fiber lasers and provide a foundation for studying mode-locking nonlinear evolutionary paths.