Ultrafast thulium-doped fiber laser mode-locked by antimonides

We report, for the first time, the nonlinear absorption at the 2 mu m waveband of three Sb-related materials including two Sb compounds, GaSb and InSb, and one Sb alloy, Ge8Sb92. These saturable absorbers (SAs) were coated on tapered single mode fibers by the magnetron-sputtering deposition method. By incorporating these SAs into Tm-doped fiber lasers, ultrafast mode-locked solitons could be readily obtained. Stable pulse trains with 922 fs/753 fs/1005 fs pulse durations, 31.35 mW/37.70 mW/16.60 mW output powers, 93 dB/80 dB/92 dB signal-to-noise ratios were achieved with GaSb/InSb/Ge8Sb92, respectively. Our findings demonstrate that these materials can be widely used for photonic devices in the 2 mu m waveband where ultrafast optical switching and modulating are desired. (C) 2021 Optical Society of America under the terms of the OSA Open Access Publishing Agreement.

Automated summary

This study presents the nonlinear absorption of three Sb-related materials in the 2 μm waveband, showing their potential for use in photonic devices requiring ultrafast optical switching and modulation. The materials exhibited stable pulse durations, output powers, and signal-to-noise ratios, indicating their suitability for applications in Tm-doped fiber lasers.