Infrared optical tellurite glass fibers

The liquid viscosities of glass-forming telluria-alumina (6–11 wt% alumina) were found to be high relative to those of 100% telluria, but not high enough to permit processing of glass fibers by conventional methods, i.e., down-drawing from a preform or extrusion (spinning) through an orifice. The viscosities were, however, sufficiently high that the first tellurite fibers on record could be up-drawn from the surface of supercooled melts below the liquidus. A high speed, low cost process is feasible if development of infrared tellurite fibers is warranted.