Droplet Spraying of Heavy Metal Fluoride Glass for Optical Waveguide Fabrication.

Most heavy metal fluoride glass fiber fabrication techniques are based on casting of the fiber preform. These techniques are intrinsically limited in their thermal quenching rate. This results in crystallization and hence high light scattering losses. This is currently the main obstacle in obtaining very low attenuation in fluoride glass fibers. The quenching rate can be significantly enhanced by deposition of thin glass layers. We have demonstrated the feasibility of a new technique in which molten fluoride glass is atomized into small droplets and sprayed onto a preform bait. Using externally-mixed, siphon gas-melt atomizers, very rapidly quenched amorphous ZrF sub 4 -BaF sub 2 -LaF sub 3 -AlF sub 3 -NaF particles were obtained.