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:
Sep. 23, 2003
Filed:
May. 01, 2001
Takeshi Kyogoku, Yokohama, JP;
Masumi Ito, Yokohama, JP;
Takehiko Kito, Yokohama, JP;
Sumio Hoshino, Yokohama, JP;
Sumitomo Electric Industries, Ltd., Osaka, JP;
Abstract
For an index change of an interfacial region which is formed in a boundary between core region and cladding region and which decreases its refractive indices from the core region side to the cladding region side, a change rate in relative index difference (0.5×&Dgr;n)/(d/r) normalized by a core radius r, obtained for a domain of change from 0.8×&Dgr;n to 0.3×&Dgr;n relative to a relative index difference &Dgr;n of the core region , is used as an index for evaluation of refractive index change and an allowable range of values thereof is set to a range of the lower limit of 0.4% to the upper limit of 4.0%, whereby a single-mode optical fiber capable of low loss phototransmission can be realized while reducing influence of a tail spread and strain in the optical fiber.