∼100 nm wavelength tunable noise-like pulse based on two-dimensional parameter optimization of Tm-doped fiber laser

Abstract

We report a wavelength widely-tuned noise-like pulse (NLP) thulium-doped fiber laser. Free of additional filter, NLP with a wavelength tunable range of ∼ 100 nm is realized by lowering the formation threshold power of NLP at different wavelengths and combining with intracavity birefringent filter. With the optimized two-dimensional intracavity parameters (gain fiber length of 2.9 m and single mode fiber length of 45 m), the NLP fiber laser achieves an adjustable wavelength from 1873.4 nm to 1969.3 nm (95.9 nm wavelength tunable range). The pulse width and average power of the NLP in the tuning range vary from 6.46 ns to 16.86 ns and from 0.211 W to 0.355 W, respectively. To our knowledge, this is the widest wavelength tunable NLP fiber laser, capable of variety applications in optical coherence tomography, material processing, imaging and so on.