Abstract
Fluoride glasses, in spite of only 80 years old, have been widely developed with many kind of different
compositions so far, because of its attractive properties, for example, high transparency in wide spectral
range between visible and mid-infrared, and low phonon energy property that enhances the emission of
many active ions. Many researchers have been challenging to make fluoride glass optical fibers,
however, fluoride glasses are generally weak at humidity and have difficulty of glass formation due to
crystallization or high susceptibility of viscosity to temperature, thus a fluoride glass is still one of the
most difficult glass-system to draw optical fibers. In this paper, with surveying fluoride glasses and
fibers, I introduce the waterproof fluoride glass (fluoroaluminate glass system) and fiber that we
developed. The waterproof fluoride glass fiber is expected to use for multi-color visible lasers and midinfrared
fiber lasers.
