-
公开(公告)号：US20230221487A1
公开(公告)日：2023-07-13
申请号：US18009784
申请日：2020-06-24
Applicant: NIPPON TELEGRAPH AND TELEPHONE CORPORATION
Inventor： Nobutomo HANZAWA , Takashi MATSUI , Yuto SAGAE , Kazuhide NAKAJIMA
IPC: G02B6/02
CPC classification number: G02B6/02042 , G02B6/02342
Abstract: The purpose of the present invention is to provide an optical fiber evaluation equipment and an optical fiber evaluation method that evaluate the center of a cladding of an MCF and a deviation of the center of each core of the MCF from a design value with ease and high accuracy.
The optical fiber evaluation equipment according to the present invention approximates the outside diameter of a cladding by a circle, based on a cross-sectional image of an MCF, and determines the center of the circle as the center of the cladding. In addition, the optical fiber evaluation equipment according to the present invention obtains the center coordinates of cores with an origin at the center of the circle, rotates the cross-sectional image so as to minimize a difference between the center coordinates and design coordinates of each core, and derives the minimum value thereof as the amount of deviation of the center of each core.-
公开(公告)号：US20220294537A1
公开(公告)日：2022-09-15
申请号：US17633902
申请日：2019-08-23
Applicant: NIPPON TELEGRAPH AND TELEPHONE CORPORATION
Inventor： Taiji SAKAMOTO , Masaki WADA , Takashi YAMAMOTO , Kazuhide NAKAJIMA
IPC: H04B10/61 , H04B10/2581 , H04B10/2575
Abstract: An object of the present invention is to provide an optical transmission system capable of easily controlling a transmission capacity and an optical signal quality even if a MIMO equalizer is provided. The optical transmission system according to the present invention is provided with an N×M MIMO equalizer, includes receivers (N units) equal in number to the spatial multiplexing order L of an optical fiber, and changes the number M of the signal beams of light transmitted through the optical fiber in the range of the spatial multiplex order L or less. The adjustment of the number M of signal beams of light makes it possible to adjust a transmission capacity and a signal quality of the optical transmission system even after construction of the transmission line.
-
63.发明申请公开(公告)号：US20220170817A1
公开(公告)日：2022-06-02
申请号：US17434949
申请日：2020-02-19
Applicant: NIPPON TELEGRAPH AND TELEPHONE CORPORATION
Inventor： Yuto SAGAE , Takashi MATSUI , Kyozo TSUJIKAWA , Kazuhide NAKAJIMA
IPC: G01M11/00
Abstract: An objective is to provide an acoustic mode propagation speed measurement method and an acoustic mode propagation speed measurement device capable of measuring a propagation speed of an acoustic mode without cutting or processing an optical fiber wire.
According to the present invention, an acoustic mode propagation speed measurement method includes: acquiring a frequency shift spectrum of Brillouin scattered light generated in an optical fiber; fitting the frequency shift spectrum using a Gauss function; acquiring a spectral full-width at half maximum w from a fitted curve using the Gauss function; and calculating a propagation speed VA of an acoustic mode of the optical fiber by substituting the acquired spectral full-width at half maximum w into a linear function of the spectral full-width at half maximum w and the propagation speed VA of the acoustic mode.-
64.发明申请公开(公告)号：US20200379187A1
公开(公告)日：2020-12-03
申请号：US16770531
申请日：2018-12-20
Applicant: NIPPON TELEGRAPH AND TELEPHONE CORPORATION
Inventor： Takashi MATSUI , Kazuhide NAKAJIMA , Masaki WADA , Yoko YAMASHITA
IPC: G02B6/38
Abstract: According to the connection device, the connection method, the optical connector manufacturing device, and the method for manufacturing an optical connector, rotation alignment of an MCF becomes unnecessary because an image of an end surface of the MCF to be connected is captured, the position of the core is located, and an optical waveguide is formed on a substrate so as to match the position. Thus, it is possible to solve the problem of increasing loss or complex connection work caused by rotational misalignment in association with rotation alignment.
-
Patent Agency Ranking
公开(公告)号：US20200225407A1
公开(公告)日：2020-07-16
申请号：US16633424
申请日：2018-07-31
Applicant: NIPPON TELEGRAPH AND TELEPHONE CORPORATION
Inventor： Azusa URUSHIBARA , Taiji SAKAMOTO , Masaki WADA , Takashi YAMAMOTO , Kazuhide NAKAJIMA , Takayoshi MORI
IPC: G02B6/02 , H01S3/10 , H04B10/2581
Abstract: The optical fiber of the present invention includes a core, and a cladding that is provided on an outer periphery of the core and has a refractive index lower than a refractive index of the core region. In the optical fiber of the present invention, a V value representing a normalized frequency of an LP02 mode is greater than or equal to 4.8 and less than or equal to 6.4.
-
公开(公告)号：US20190339513A1
公开(公告)日：2019-11-07
申请号：US16507570
申请日：2019-07-10
Applicant: NIPPON TELEGRAPH AND TELEPHONE CORPORATION
Inventor： Takashi MATSUI , Kazuhide NAKAJIMA , Kyozo TSUJIKAWA , Fumihiko YAMAMOTO
Abstract: A photonic crystal fiber according to the present invention has a plurality of holes arranged in the optical fiber along a longitudinal direction, in which the holes are arranged such that, in a cross section, a hole ratio which is an area of the holes per unit area is larger in a central side than in an outer side in a portion corresponding to a cladding and that a wide core area can be obtained while the number of modes that can be propagated is limited to several. Moreover, in a high-power optical transmission system according to the present invention, the amount of axis misalignment between the central axis of a laser oscillator and the central axis of the photonic crystal fiber is less than or equal to a certain amount.
-
公开(公告)号：US20190196106A1
公开(公告)日：2019-06-27
申请号：US16322432
申请日：2017-08-01
Applicant: NIPPON TELEGRAPH AND TELEPHONE CORPORATION
Inventor： Masaki WADA , Taiji SAKAMOTO , Takayoshi MORI , Shinichi AOZASA , Takashi YAMAMOTO , Kazuhide NAKAJIMA
Abstract: A differential mode attenuation compensator includes a first multi-mode optical fiber and a third multi-mode optical fiber in which a plurality of propagation modes propagate in a wavelength of a propagating optical signal; and a second multi-mode optical fiber including a core and a clad and arranged with a central axis aligned between the first multi-mode optical fiber and the third multi-mode optical fiber, in which each loss in the plurality of propagation modes is different in the first multi-mode optical fiber and the third multi-mode optical fiber.
-
公开(公告)号：US20190170931A1
公开(公告)日：2019-06-06
申请号：US16313724
申请日：2017-06-21
Applicant: NIPPON TELEGRAPH AND TELEPHONE CORPORATION
Inventor： Taiji SAKAMOTO , Takashi MATSUI , Kazuhide NAKAJIMA , Kotaro SAITOH
Abstract: An optical connector is provided which includes at least one multi-core block fixing and holding a plurality of multi-core optical fibers in a state where a position in a direction orthogonal to an optical axis of each multi-core optical fiber and a rotation angle around the optical axis are in a predetermined state, and a ferrule including an accommodating portion accommodating the multi-core block.
-
公开(公告)号：US20180372954A1
公开(公告)日：2018-12-27
申请号：US16062034
申请日：2016-12-27
Applicant: NIPPON TELEGRAPH AND TELEPHONE CORPORATION
Inventor： Takashi MATSUI , Kazuhide NAKAJIMA , Taiji SAKAMOTO , Koutaro SAITO
Abstract: An alignment apparatus that can efficiently align an optical fiber, and an alignment method will be provided.According to the embodiments, the alignment apparatus that aligns an optical fiber comprises an acquisition unit, a calculation unit, and a rotation processing unit. The acquisition unit acquires one or more side images of the optical fiber. The calculation unit calculates correlation coefficients between the luminances of the one or more side images and those of one or more reference side images. The rotation processing unit rotates the optical fiber in the axis direction of the optical fiber so that the correlation coefficients peak.
-
-
-
-
-
-
-
-
Search Results
69
records
(took 0.022 seconds)
