Abundant dynamics of group velocity locked vector solitons from Er-doped fiber laser based on GO/PVA film

Abstract

With the insertion a segment of polarization-maintaining fiber (PMF) inside the cavity, abundant dynamics of group velocity locked vector solitons (GVLVSs) in Er-doped fiber laser have been investigated by using graphene oxide/polyvinyl alcohol (GO/PVA) film as a saturable absorber (SA). The generated Kelly sidebands in emission spectra reveal peak-valley or valley-peak alternation and slightly shift in two orthogonal components, which are the characteristics of GVLVSs. Through proper adjustment of polarization controllers (PCs) inside the EDFLs cavity, versatile vector soliton dynamics such as polarization locked GVLVSs (PL-GVLVSs), polarization rotation GVLVSs (PR-GVLVSs), dual wavelength GVLVSs, bound state GVLVSs, bunch GVLVSs and harmonic mode-locking GVLVSs (HML-GVLVSs) have been observed. The separation between two emission peaks from the dual wavelength GVLVSs was controlled by the Lyot filter and related to the insertion length of PMF inside the cavity. Unlike PL-GVLVSs, the period-doubling phenomenon has been found in two orthogonal components of the PR-GVLVSs. Besides, the bound state GVLVSs were generated showing strongly modulated interference fringes in emission spectrum. For the bunch and HML GVLVSs, the number of solitons inside the cavity increased with the pump power, and it showed the quintuple solitons and the 7th HML-GVLVSs at the highest pump power.

Keywords

• dual wavelength
• graphene oxide
• group velocity locked vector solitons
• lyot filter
• multiple soliton