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:
Jan. 16, 2001
Filed:
Mar. 19, 1998
Shinichi Arai, Ichihara, JP;
Noritsugu Enomoto, Ichihara, JP;
Youichi Akasaka, Ichihara, JP;
Tamotsu Kamiya, Funabashi, JP;
The Furukawa Electric Co. Ltd., Tokyo, JP;
Abstract
The present invention relates to a dispersion shifted optical fiber having zero dispersion at a wavelength band of 1.5 &mgr;m, which suppresses an increase of transmission loss and an increase of polarization mode dispersion when carrying out fiber drawing. An optical fiber according the invention is provided with the first core (refractive index n,.), the second core (refractive index n,), the first clad (refractive index n,) and second clad (refractive index n,) in this order from the center to outside, wherein the abovementioned refractive indexes are in a relationship of n,>n,>n,>n,, Ge which is at a ratio of 0.4 to 1.0% for the value of relative refractive index difference with respect to the second clad is doped on the first core, which is at a ratio of 0.1 to 0.5% for the value of relative refractive index difference with respect to the second clad is doped on the second core as in the above, and the second clad is SiO,, which has a thickness from 1 &mgr;m or more to 40 &mgr;m or less.