SOL-GEL SYNTHESIS OF HIGH-QUALITY HEAVY-METAL FLUORIDE GLASSES

Fluoride glasses are excellent laser hosts and are very well suited for a broad spectrum of optical applications. However, current fluoride glass synthesis is expensive. The sol-gel method is an affordable alternative for producing high-performance, optical-quality heavy-metal fluoride glasses. The method involves forming a hydrous oxide gel of the constituent metal alkoxides and salts, polymerizing the solution to form a gel, fluorinating the gel with anhydrous HF, melting the amorphous material in an oxidizing atmosphere of SF6, and casting the melt into desired shapes. ZBLA (57ZrF4.36BaF2.4LaF3.3AlF3, in mol%) and Nd-doped (0.3 mol%) ZBLA glass rods were prepared by this process and their properties were measured. The sol-gel-based glasses had thermal and optical properties similar to those found in the literature for conventionally prepared fluorides.