Measurement method, measurement device, and non-transitory recording medium
US10760993B2 · kind B2 · utility
Assignees
Inventors
Key dates
| Filing date | May 1, 2017 |
| Grant date | Sep 1, 2020 |
| Priority date | — |
| Expiry date | Jun 14, 2037 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01M11/39
- WIPO fieldMeasurement
- WIPO sectorInstruments
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 ν1 by 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 ν2 by 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 Δneff in accordance with Δneff=(ν1−ν2)/(2kVL) with use of the first Brillouin frequency shift ν1, the second Brillouin frequency shift ν2, a predetermined wave number k of light in a vacuum, and a predetermined constant VL.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.