Abstract

Mid-infrared fiber lasers operating around 3.5 μm find applications in various fields such as remote sensing, polymer processing and spectroscopy. Recent demonstrations based on the ⁴F_9/2 ⟶ ⁴I_9/2 transition in Er³⁺:ZrF₄ fibers have shown effective laser emission up to 1.52 W [1] by relying on a dual-wavelength pumping (DWP) scheme. This novel approach mitigates the low Stokes efficiency associated with single-wavelength pumping and reduces ion bottlenecking in lower lying energy states. Here, we report the first monolithic DWP erbium doped all-fiber laser bounded by two fiber Bragg gratings (FBGs) emitting ~ 3.4 W at 3.55 μm with a total optical efficiency of 22 %. To the best of our knowledge, these results represent the highest output power and efficiency ever achieved at this wavelength in a rare-earth doped fiber laser.

© 2017 IEEE