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. 11, 2002
Filed:
Jan. 17, 2001
The Furukawa Electric Co., Ltd., Tokyo, JP;
Abstract
The present invention provides an optical fiber which has negative dispersion and negative dispersion slope in a wavelength band in use, and can carry out single-mode operation in which distortion due to the non-linear phenomenon can be suppressed so as to be suitable for wavelength multiplexed optical transmissions. When the relative index differences of center core ( ), first side core ( ), second side core ( ), and inner cladding ( ) from the silica level are &Dgr;1, &Dgr;2, &Dgr;3, and &Dgr;4, l.7%≦&Dgr;1, &Dgr;2≦−0.3%, 0.25%≦&Dgr;3, and &Dgr;4<0. Furthermore, the value A, determined by dividing the diameter a1 of the center core by the diameter a2 of the first side core , is set to 0.15≦A≦0.2, and the value B, determined by dividing the diameter a3 of the second side core by the diameter a2 of the first side core , is set to 1<B≦2. By such an arrangement, the absolute values of the negative dispersion and negative dispersion slope in a wavelength band of 1.55 &mgr;m can be made large, and in addition, light is confined within the core by the second side core ( ), the effective core sectional area is made larger, and inner cladding ( ) is provided, whereby the effective cut-off wavelength is shortened.