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. 01, 2020
Filed:
May. 01, 2017
Fujikura Ltd., Tokyo, JP;
National University Corporation Shimane University, Shimane, JP;
Fujikura Ltd., Tokyo, JP;
NATIONAL UNIVERSITY CORPORATION SHIMANE UNIVERSITY, Shimane, JP;
Abstract
A measurement method for measuring an effective refractive index difference between two propagation modes of a multimode fiber is provided. The method includes: measuring a first Brillouin frequency shift νby specifying a frequency having a lowest-frequency peak out of peaks in a first frequency spectrum of scattered light in a first propagation mode; measuring a second Brillouin frequency shift νby specifying a frequency having a lowest-frequency peak out of peaks in a second frequency spectrum of scattered light in a second propagation mode; and calculating an effective refractive index difference Δnin accordance with Δn=(ν)/(2kV) with use of the first Brillouin frequency shift ν, the second Brillouin frequency shift ν, a predetermined wave number k of light in a vacuum, and a predetermined constant V.