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:
May. 10, 2005
Filed:
Dec. 30, 2003
Katsuya Nagayama, Yokohama, JP;
Kiichiro Kawasaki, Yokohama, JP;
Takatoshi Kato, Yokohama, JP;
Sumitomo Electric Industries, Ltd., Osaka, JP;
Abstract
An optical fiber comprising a core regiondoped with Cl which raises the refractive index; and a cladding region, provided at the outer periphery of the core region, having a cladding layerdoped with F which lowers the refractive index is formed. The cladding regionto become the outermost cladding layer is configured such that the doping amount of F successively decreases within an outer peripheral partincluding the outer periphery thereof to a predetermined doping amount which is the minimum doping amount of F within the cladding layer. Therefore, the stress within the optical fiber is dispersed into the outer peripheral parthaving an enhanced viscosity, whereby the stress concentration into the core is suppressed. Since the favorable tension range at the time of drawing the optical fiber becomes wider at this time, tension control is facilitated.