PRODUCTION OF FLUORIDE GLASS OPTICAL WAVEGUIDE

摘要

PURPOSE:To decrease the eccentricity of a core of a fluoride glass optical waveguide produced by inserting a fluoride glass rod into a fluoride glass pipe and integrating the components by selecting the maximum outer diameter and the minimum outer diameter of the rod and the inner diameter of the pipe to satisfy a specific relationship. CONSTITUTION:A fluoride glass having a composition of ZrF4-BaF2-LaF3-AlF3- NaF, etc., and doped with specific amounts of compounds containing rare earth elements such as Pr (e.g. PrF3) and PbF2 is melted and cast into a mold to form a core rod having prescribed maximum outer diameter d1 and minimum outer diameter d2. Separately, a pipe for clad having a prescribed inner diameter D is produced from a ZrF4-BaF2-LaF3-AlF3-NaF fluoride glass doped with a specific amount of HfF4, etc. The rod for core is inserted into the pipe for clad in such a manner as to satisfy the relationships of 0<=(D-d1)<=0.2mm, d1>=d2>=(d1)/2 and a core eccentricity of <=0.2%. The assembly is integrated by heating in an inert gas such as Ar and drawn to obtain the objective fluoride glass optical waveguide for light amplification.