Group-velocity-locked vector soliton molecules in a birefringence-enhanced fiber laser

TL;DR

This paper reports the first experimental observation of group-velocity-locked vector soliton molecules in a birefringence-enhanced fiber laser, revealing complex multi-soliton interactions and formations in a novel laser setup.

Contribution

It introduces a birefringence-enhanced fiber laser enabling the generation and observation of GVLVS molecules, a new type of multi-soliton complex in fiber lasers.

Findings

Observation of GVLVS molecules with various soliton separations

Coupling of orthogonally polarized components into multi-soliton complexes

Spectral fringes and double-humped profiles support soliton molecule formation

Abstract

Physics phenomena of multi-soliton complexes have enriched the life of dissipative solitons in fiber lasers. By developing a birefringence-enhanced fiber laser, we report the first experimental observation of group-velocity-locked vector soliton (GVLVS) molecules. The birefringence-enhanced fiber laser facilitates the generation of GVLVSs, where the two orthogonally polarized components are coupled together to form a multi-soliton complex. Moreover, the interaction of repulsive and attractive forces between multiple pulses binds the particle-like GVLVSs together in time domain to further form compound multi-soliton complexes, namely GVLVS molecules. By adopting the polarization-resolved measurement, we show that the two orthogonally polarized components of the GVLVS molecules are both soliton molecules supported by the strongly modulated spectral fringes and the double-humped intensity profiles. Additionally, GVLVS molecules with various soliton separations are also observed by adjusting the pump power and the polarization controller.