FABRICATION OF FLUORIDE GLASS SINGLE MODE OPTICAL FIBER

摘要

PURPOSE: To efficiently obtain single mode optical fibers by preparing a tube comprising an external layer for a clad and an internal layer for a core made of a fluoride glass, making the internal layer thin by executing chemical etching in a specific quantity and then line-drawing. ;CONSTITUTION: Molten glass constituent having a composition suitable to form the clad of single mode optical fibers made of a fluoride glass is poured into a mold 1 and then the mold 1 is rapidly rotated to form the external layer 2. After the external layer 2 solidifys, a molten glass constituent having a composition suitable to form the core is poured into a hole 3 in the external layer 2 and then the mold 1 is rotated to form the internal layer 4. Then, the internal layer 4 is made thinner by executing chemical etching at an ambient temp. until ratio of volume of the internal layer 4 to volume of the external layer 2 becomes equivalent to ratio of a core diameter to a clad diameter which is necessary for the single mode optical fiber. Then the obtained tube is line- drawn to obtain the single mode optical fibers made of a fluoride glass.;COPYRIGHT: (C)1995,JPO