PURPOSE: To produce optical fibers having improved transmittance for infrared rays, particularly about 2W6μ wavelength, by heat-treating a raw material for chalcogenide glass in a fluoride atmosphere, melting and vitrifying the heat- treated raw material, and spinning the resultant glass.
CONSTITUTION: A Ge block of high purity and an Se shot of high purity are heated at about 900°C in an atmosphere of a fluorine compound gas, e.g. SeF6, for about 120min, melted in a vacuum under stirring, and cooled to room temperature to prepare a glass block, which is then ground in the form of a rod. The resultant preform is then drawn into a fiber under heating to give an optical fiber. According to theabove-mentioned method, hydrogen contained in the raw materials (Ge and Se) in a very small amount is replaced with fluorine by heat treatment to vanish absorption (about 4.5μ wave length) due to the Se-H bond to give the optical fiber having low transmission loss over about 2W8μ wavelength. The above-mentioned method is also applicable to a chalcogenide glass, e.g. Ge-S, Ge-Te or Ge-As-Se, other than the Ge-Se system.
ISHIDA KOUJI
MATSUMURA HIROYOSHI
HITACHI CABLE
| JPS58120538A | 1983-07-18 | |||
| JPS5742551A | 1982-03-10 |