Feasibility study of Yb:YAG-derived silicate fibers with large Yb content as gain media

We present spectroscopic measurements and amplifier experiments on a new type of Yb-doped glass optical fiber derived from Yb:YAG crystal rods. The goal of this work is to provide a feasibility analysis of these novel silicate glasses as heavily-doped gain media for fiber-amplifier applications. Amplifier performance currently is limited by background losses arising from the precursor crystalline rod. Both basic spectroscopic measurements and fiber amplifier experiments, in addition to modeling efforts that include the background losses, are presented. The findings show that Yb:YAG-derived fibers are spectroscopically very similar to more conventional Yb-doped aluminosilicate materials but can be doped to considerably higher concentration, generally have greater doping and compositional uniformity, and possess advantageous stimulated Brillouin scattering (SBS) characteristics.

► Fabrication of novel optical fibers derived from Yb:YAG crystals is presented.
► Basic spectroscopic measurements performed on these fibers are presented.
► Amplifier measurements are performed on these optical fibers.
► Modeling efforts are presented to understand performance limitations.
► YAG-derived fibers are promising as gain media for high-power narrow linewidth fiber lasers.