| 摘要 |
PURPOSE:To obtain an IR transmittable optical fiber having an excellent light transmission characteristic by executing either of a stage for forming an ion crystalline material into a polycrystal fiber by a plastic working method and a stage for heating the fiber at the temp. at which the growth of crystal grain sizes is obviated or below in an inert gaseous atmosphere. CONSTITUTION:The ion crystalline material 8 such as CaBr, KCl or KRS-5 is loaded into a cylinder 1 and is extruded by a piston 2 under 5,000-10,000atm extrusion pressure to manufacture polycrystal IR transmission fiber 9. Since the fiber 9 has the crystal defect by the plastic working, the fiber is conducted into a heating furnace 5 in order to eliminate the defect and gaseous Ar without contg. O2 and moisture is fed from an inert gas supply system to the inside of a casing 7 so that the deterioration of the fiber 9 by oxidation and the deterioration in the light transmission characteristic thereof are prevented and the fiber is heat-treated at the temp. to prevent the growth of the crystal grains. The IR transmission fiber having a low transmission loss is thus obtd. |
