Infrared optical fiber and method for manufacture thereof
AssigneesAgency of Industrial Science and Technology, Ministry of International Trade & Industry
InventorsShiro Sakuragi, Haruo Kotani
Life of this patent
Estimating the term…
Abstract
A preform is prepared to comprise a step index structure consisting of a core and a clad both made of metal halogenides or arsenic-selenium glass sparingly capable of transmitting infrared light of long wavelength and a layer of lubricant applied to the outer surface of the clad. The preform is set inside a metal cylinder. By pulling this metal cylinder through a plurality of dies containing orifices of successively decreased diameters at a temperature below the melting point, the preform can be elongated into an optical fiber of a prescribed diameter. The optical fiber thus produced is capable of transmitting infrared light of high power with a small loss. Protected and reinforced by the metal cylinder jacket, this fiber enjoys high mechanical strength.
Claims12
An infrared optical fiber, comprising a core made of an infrared transmitting substance, a clad around said core made of a infrared transmitting substance having a lower index of refraction then said core, a layer of lubricant on the outer surface of said clad, and a metal pipe enveloping said layer of lubricant.
A method for the manufacture of an infrared optical fiber, which comprises the steps of preparing a preform composed of a core made of an infrared transmitting substance, a clad around said core made of an infrared transmitting substance having a lower index of refraction than said core, and a layer of lubricant on the outer surface of said clad, placing said preform within a metal cylinder, sealing it airtightly therein, and forcing said metal cylinder containing said preform therein through dies at a temperature lower than the melting points of said core and said clad.
Dependencies are inferred from the claim text.