A small volume cell was used to obtain the high temperature viscosity
of fluid, easily devitrified glass melts. This cell was used to obtain
the high temperature viscosity of cadmium halide glass compositions i
dentified for use in optical waveguide amplifier fibers. Low temperatu
re viscosities were obtained using beam bending methods; the resulting
viscosity data were fitted by the Cohen-Grest equation. From these fi
ndings, the optimum fiber draw region was identified. The fragility of
these glasses, relative to other halide glasses will be discussed.