Learn more about our fluoride glass fibers specifications
Since the discovery of ZBLAN glasses in 1974, Le Verre Fluoré has worked to develop a large range of fluoride optical fibers, including ZrF4, InF3 and AlF3 based optical fibers, designed for mid-infrared applications.
Typical compositions for ZFG and IFG glasses are:
ZFG (Zirconium ZrF4 Fluoride Glass) = fluorozirconate fibers
53 ZrF4-20 BaF2-4 LaF3-3 AlF3-20 NaF
IFG (Indium InF3 Fluoride Glass) = fluoroindate fibers
40 InF3-20 ZnF2-20 SrF2-20 BaF2
They have the specificity to exhibit a high transparency from UV to mid-infrared : from 0.22 up to 7 µm and 0.255 up to 8 µm in case of ZFG and IFG (3 mm thick samples), respectively. (See figure below)
As a result, they totally cover the 3-5 µm atmospheric transparency window and partially covers the molecular fingerprinting region, paving the way to numerous passive and active applications.
Here are given some ZFG and IFG glass properties (see table) :
Glass transition temperature Tg (°C)
Refractive index nD
Non linear refractive index n2(x 10-20 m²/W)
≈ 3.2-4.3 [ref.]
Phonon energy (cm-1)
Below, the figure including arrows will enable you to appreciate fluoride properties compared to silica and chalcogenide glasses.