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Patent Searching and Data


Title:
OPTICAL PULSE TESTING METHOD AND OPTICAL PULSE TESTING DEVICE
Document Type and Number:
WIPO Patent Application WO/2021/075015
Kind Code:
A1
Abstract:
The purpose of the present invention is to propose, for DAS-P, a designing method using a minimum value N of a frequency multiplexing number for measuring an intended vibration frequency with tradeoff between a measured distance and an upper limit of measurable vibration frequencies taken into account. When a phase shift in any section of an optical fiber to be measured is denoted as A × sin(2πfvt), it is assumed that for A of smaller than π/2, N = 4Zfv/ν and that for A of π/2 or greater, N = 2Zfv/(ν·Arcsin(π/2A)). Here, fv denotes a vibration frequency, t denotes time, Z denotes the length of the optical fiber to be measured (measured distance), and ν denotes the speed of light in the optical fiber to be measured.

Inventors:
WAKISAKA YOSHIFUMI (JP)
IIDA DAISUKE (JP)
OSHIDA HIROYUKI (JP)
Application Number:
PCT/JP2019/040821
Publication Date:
April 22, 2021
Filing Date:
October 17, 2019
Export Citation:
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Assignee:
NIPPON TELEGRAPH & TELEPHONE (JP)
International Classes:
G01H9/00
Attorney, Agent or Firm:
OKADA, Kenji et al. (JP)
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