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. 03, 2026
Filed:
Nov. 11, 2021
Ntt, Inc., Tokyo, JP;
NTT, Inc., Tokyo, JP;
Abstract
An object of the present invention is to provide an optical transmission line test apparatus and a test method capable of measuring a cumulative crosstalk of an optical transmission line in which a plurality of uncoupled multi-core fibers are connected in series from one end side with an OTDR. An optical transmission line test apparatusaccording to the present invention measures a cumulative crosstalk of an optical transmission linein which a plurality of uncoupled multi-core fibers-are connected in series. The optical transmission line test apparatusincludes a test light input unitthat inputs optical pulses to each of cores of the uncoupled multi-core fiber-at one endof the optical transmission line; a reception unitthat receives backscattered light for each of the cores output from one end; and a calculation unitthat acquires a loss distribution occurring in each of the cores from the backscattered light, and calculates the cumulative crosstalk from a connection loss at a connection point zj of the uncoupled multi-core fiber obtained from the loss distribution and a known inter-core mode coupling of each of the uncoupled multi-core fibers-