1.7-μm Tm-doped fiber laser intracavity-pumped by an erbium/ytterbium-codoped fiber laser

In this paper, we demonstrate an efficient 1.7-mu m Tm-doped fiber laser whose cavity was embedded in a 1560 nm erbium/ytterbium-codoped fiber laser cavity, which enabled bidirectional pumping and made full use of the circulating pump in the parent laser cavity. A rate equation model was developed to optimize the fiber length and output coupling for a desired output power. In the experiment, a maximum output power at 1720 nm of 1.13 W was obtained under 10 W of 976 nm diode pump power, which correlated well with our modeling. The slope efficiency from the multimode 976 nm diode pump to 1720 nm output was 13.5%, while the slope efficiency in terms of launched 1560 nm pump power reached 62.5%. By using a short Tm-doped fiber to minimize signal reabsorption, a high signal-to-noise ratio over 65 dB was achieved. The prospect for further power scaling was also discussed based on our developed model. (C) 2021 Optical Society of America under the terms of the OSA Open Access Publishing Agreement

Automated summary

This paper presents an efficient 1.7-micron Tm-doped fiber laser with bidirectional pumping embedded in a 1560 nm erbium/ytterbium-codoped fiber laser cavity. A rate equation model was developed to optimize fiber length and output coupling for desired power, achieving a maximum output power at 1720 nm of 1.13 W. High signal-to-noise ratio and potential for further power scaling were also discussed.