Mode-locked thulium-doped fiber laser with microfiber based polarization beam splitter

Abstract

We report on a passively mode-locked thulium-doped all-fiber laser utilizing our fabricated microfiber-based polarization beam splitters (PBSs). The all-fiber PBSs composed of two parallel and coupled microfibers are fabricated to separate light in two orthogonal polarizations, when the coupling region length and microfiber diameter are appropriately chosen to meet the polarization splitting condition. By incorporating the PBSs into the thulium-doped fiber laser cavity, both traditional and dispersion-management solitons at anomalous and near-zero dispersion regimes have been attained. The experimental results have validated the potential of the microfiber-based PBS as an ideal artificial saturable absorber in mode-locked fiber laser, as well as other fiber systems.