PRODUCTION OF OPTICAL FIBER FOR INFRARED LIGHT

摘要

PURPOSE:To eliminate the liberation of the grain boundaries and impurity elements in a fiber by using a single crystal for the base crystal for the fiber and converting the same to a polycrystalline fiber. CONSTITUTION:The single crystal is used for the base crystal for the fiber and is converted to the polycrystalline fiber by a heating extrusion method. Thallium halide, silver halide or cesium halide is preferably used and the crystal (KRS-5) of TlBr-TlI (40-45wt.% TlBr) is more preferably used for the base material of the single crystal. For example, the polycrystalline IR optical fiber 2 is produced by heating a perform crystal 1 consisting of the KRS-5 single crystal to a desired temp. and extruding the same. The fiber 2 with which the heat generation by the liberation of the grain boundaries and impurity elements is decreased and which is capable of transmitting high energy is thereby obtd.