FBG-Stabilized Dysprosium:Fluoroindate Mid-Infrared Fiber Laser

Recent studies suggest fluoroindate (InF3 glass fibers to be better suited for the development of mid-infrared fiber lasers systems as compared to the commonly used fluorozirconate (ZBLAN) fibers [1]. The extended transparency window up to 5.5
$\upmu \mathrm{m}$
and the increased resistance to water ingress [2] allowed the demonstration of laser emission in 3 - 4
$\upmu \mathrm{m}$
region using a variety of dopants as well as record output powers in the 4
$\upmu \mathrm{m}$
region [3]. However, the reported efficiencies to date are all well below the Stokes limit, suggesting background loss (BL) to be a limiting factor for power scaling of fluoroindate fiber lasers [4].