Self-pulsing dynamics of ytterbium-doped fiber laser with pump-bypassed cavity

In addition to efficient continuous wave laser action at 1.06 μm (⁴ F _3/2→⁴ I _11/2 transition), with a slope efficiency 30% and 30 mW pump power threshold, this work presents a throughout study of the spectroscopic, and thermo-optical properties of a 2.0 mol % Nd³⁺ doped fluoroindogallate glass. The characterization of the sample using the pump probe experimental technique indicated the presence of two broad excited state absorption bands from 0.94 to 1.05 μm (⁴ F _3/2→² D _3/2, ² G _9/2, ⁴ G _11/2, ² K _15/2) and from 1.16 to 1.42 μm (⁴ F _3/2→⁴ G _9/2, ⁴ G _7/2, ² K _13/2), found not to interfere with the stimulated emission at 1.06 μm, with a peak cross section value σ_SE = 2.55×10^-21 cm² and a full width at half maximum of 22 nm. Thermal lens measurements were performed to quantify the Auger upconversion parameter (γ=(1.26±0.09)×10^-16 cm³/s) and evaluate the thermal loading in the sample in comparison to other commercial glasses. PACS 181.05.Kf; 78.45.+h; 42.70.Hj