出典:Wikipedia
出典:『Wikipedia』 (2010/11/03 22:12 UTC 版)
Fluoride glass is a class of non-oxide optical glasses composed of fluorides of various metals. Due to their low viscosity, it is very difficult to completely avoid the occurrence of any crystallization while processing it through the glass transition (or drawing the fiber from the melt). Thus, although heavy metal fluoride glasses (HMFG) exhibit very low optical attenuation, they are not only difficult to manufacture, but are quite fragile, and have poor resistance to moisture and other environmental attacks. Their best attribute is that they lack the absorption band associated with the hydroxyl (OH) group (3200 – 3600 cm−1) which is present in nearly all oxide-based glasses.