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:
Jun. 27, 2006
Filed:
Apr. 16, 2003
Masaaki Hirano, Yokohama, JP;
Eiji Yanada, Yokohama, JP;
Tomoyuki Yokokawa, Yokohama, JP;
Takashi Sasaki, Yokohama, JP;
Masaaki Hirano, Yokohama, JP;
Eiji Yanada, Yokohama, JP;
Tomoyuki Yokokawa, Yokohama, JP;
Takashi Sasaki, Yokohama, JP;
Sumitomo Electric Industries, Ltd., Osaka, JP;
Abstract
An optical fiber preform comprises a central core portion having a maximal value Nc of refractive index in the center, and outside the central core portion, comprising at least a depressed portion having a minimal value Nd of refractive index, a ring portion having a maximal value Nr of refractive index and an outside cladding layer having a maximal value No of refractive index. The optical fiber preform satisfies a relation of Nc≧Nr>No>Nd among the values of refractive index. A method of the optical fiber preform comprises fabricating a glass rod by inserting a rod containing at least the central core portion into a pipe containing at least the depressed portion and integrating them, fabricating a glass pipe having the ring portion, and fabricating a vitreous body by integrating the glass rod and the glass pipe by collapsing after inserting the glass rod into the glass pipe.