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:
Feb. 21, 2012
Filed:
May. 18, 2010
Hiroshi Oyamada, Gunma, JP;
Hiroshi Oyamada, Gunma, JP;
Shin-Etsu Chemical Co., Ltd., Tokyo, JP;
Abstract
Provided is an optical fiber including: a first core at a center thereof; a second core adjacent to the first core to cover a circumference of the first core; a third core adjacent to the second core to cover a circumference of the second core; and a cladding adjacent to the third core to cover a circumference of the third core, where conditions of 0.28%≦Δ≦0.4%, −0.05%≦Δ≦0.05%, −1.0%≦Δ≦−0.5%, 3.8 μm≦a≦4.5 μm, 12 μm≦b≦21 μm, and 1.5 μm≦c-b≦10 μm hold, and loss increase resulting when the optical fiber is wound on a mandrel having a diameter of 20 mm is 0.1 dB/turn or smaller at a wavelength of 1625 nm, where Δis a specific refractive index difference of the first core from the cladding refractive index, Δis a specific refractive index difference of the second core from the cladding refractive index, Δis a specific refractive index difference of the third core from the cladding refractive index, 'a' is a radius of a boundary between the first core and the second core with respect to a center of the first core, 'b' is a radius of a boundary between the second core and the third core with respect to the center of the first core, and “c” is a radius of a boundary between the third core and the cladding with respect to the center of the first core.