The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Dec. 27, 1988
Filed:
Dec. 21, 1987
Hiroshi Yokota, Yokohama, JP;
Hiroo Kanamori, Yokohama, JP;
Gotaro Tanaka, Yokohama, JP;
Hiroshi Suganuma, Yokohama, JP;
Toshio Danzuka, Yokohama, JP;
Sumitomo Electric Industries, Ltd., Osaka, JP;
Abstract
A rod-in-tube method for producing a glass preform for use in the fabrication of an optical fiber, which comprises steps of inserting a glass rod constituting a core material in a glass tube constituting a cladding material, heating the rod-tube composite by an outer heating source with introducing, in the gap between the rod and the tube, a gaseous mixture containing a silicon halogenide, a fluorine-containing compound and oxygen gas in which a ratio of silicon and fluorine (Si/F) is larger than 1/300 and smaller than 1/5, and heating and fusing the composite at a temperature not lower than 1,900.degree. C. with filling the gap by a gaseous mixture comprising a halogen-containing compound and oxygen gas; from which glass preform, an optical fiber with low attenuation of light transmission, particularly in a long wavelength range, is fabricated.