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:
Apr. 21, 1998
Filed:
Jan. 27, 1997
Katsuyuki Imoto, Saitama, JP;
Hitachi Cable, Ltd., Tokyo, JP;
Abstract
A rare earth element-doped multiple-core optical fiber 31 has a bundle of cores 32-1.about.32-7 co-doped with Er and Al, primary cladding layers 33 covering each core, and an outer cladding layer 34 covering all cores 32-1.about.32-7, wherein one core 32-1 being positioned substantially on a central axis of the outer cladding layer and surrounded by other six cores 32-2.about.32-7. A core diameter Dc of the center core 32-1 is smaller than a core diameter Do of each peripheral core 32-2.about.32-7. The power of both signal light (1.53 .mu.m.about.1.57 .mu.m wavelength bands) and pumping light (0.98 .mu.m or 1.48 .mu.m band) propagating through the center core 32-1 becomes lower and the power propagating through each core 32-1.about.32-7 is equalized, and the flatter characteristics of gain to wavelength are obtained.