Watt-level wavelength-tunable Er3+/Dy3+ codoped fluoride fiber laser around 3 μm

Compact and robust wavelength-tunable mid-infrared fiber lasers are urgently needed in the fields of spectroscopic sensing, polymer processing, and free-space communications. In this work, we experimentally reported a high-power wavelength-tunable Er 3+ /Dy 3+ codoped fluoride fiber laser by diode clad pumping at 974 nm. Adopting a ruled diffraction grating, the laser wavelength could be continuously tuned in the region of 2854 nm–3510 nm (656 nm) based on the 6 H 13/2 → 6 H 15/2 transition of Dy 3+ , where 3510 nm represented the longest wavelength achieved from a Dy 3+ -doped fluoride fiber laser. Within the wide range of 3018 nm–3331 nm (312 nm), the output power was always kept at >1 W, with the maximum power of 1.75 W obtained at 3181 nm. To the best of our knowledge, this is the first watt-level wavelength-tunable fiber laser in the region of >3 μm. Further scaling the power and expanding the tuning range are expected by increasing the pump power while protecting the pumped fiber end.