This presentation will review and compare different purification processes of starting materials and
different synthesis processes developed so far to prepare high purity rare-earth doped and un-doped
Discovered in 1975 at Rennes University and intensively developed for more than 25 years, fluoride
glasses have experienced an extraordinary development, due to their broad transmission spectrum and their
low optical loss. With a theoretical optical loss of 0.001 dB| km fluoride at 2.6 micron, fluoride glass have
been considered as material of choice for repeater less communication link. Since this goal wasn't easy to
achieve the intensive development ended in early nineties. However, the technology is quite mature to
provide high purity bulk glass, lenses and fibers for short and medium-length application. Single and multimode
fibers with optical loss lower than 10 dB|km are routinely prepared.
Furthermore, compared to silica and chalcogenide glasses, fluoride glasses can be doped with high
concentration of rare-earth element required for different applications such as, fiber laser, fiber amplifier.
They can also be prepared with lower rare earth and transition metals ions required for laser cooling