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公开(公告)号：US12158607B2
公开(公告)日：2024-12-03
申请号：US17919327
申请日：2020-04-24
Applicant: NIPPON TELEGRAPH AND TELEPHONE CORPORATION
Inventor： Yoko Yamashita , Takashi Matsui , Kazuhide Nakajima
Abstract: A mode loss difference compensator of the present disclosure includes a main waveguide configured to allow propagation of N or more modes (where N is an integer of 3 or more), a first auxiliary waveguide having, at one end thereof, a first coupling portion configured to mode-convert an LP0n mode (where n is an integer of 2 or more) propagating in the main waveguide into a fundamental mode in the first auxiliary waveguide and transfer the fundamental mode from the main waveguide to the first auxiliary waveguide and having, at the other end thereof, a second coupling portion configured to mode-convert the fundamental mode propagating in the first auxiliary waveguide into the LP0n mode (where n is an integer of 2 or more) in the main waveguide and transfer the LP0n mode from the first auxiliary waveguide to the main waveguide, and a second auxiliary waveguide having, at one end thereof, a third coupling portion configured to convert a higher-order mode, other than any LP0n mode (where n is an integer of 2 or more), propagating in the main waveguide into a fundamental mode in the second auxiliary waveguide and transfer the fundamental mode from the main waveguide to the second auxiliary waveguide and having, at the other end thereof, a terminal end portion configured to eliminate the fundamental mode propagating in the second auxiliary waveguide from the second auxiliary waveguide, wherein the main waveguide includes a loss imparting portion configured to impart a loss to a fundamental mode propagating in the main waveguide between the first and second coupling portions.
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公开(公告)号：US11366266B2
公开(公告)日：2022-06-21
申请号：US16623608
申请日：2018-07-03
Applicant: NIPPON TELEGRAPH AND TELEPHONE CORPORATION
Inventor： Yuto Sagae , Kazuhide Nakajima , Takashi Matsui
Abstract: An optical fiber includes a core, a first clad that is provided on an outer circumferential portion of the core and has a refractive index lower than that of the core, and a second clad that is provided on an outer circumferential portion of the first clad and has a refractive index lower than that of the first clad. In the optical fiber, a mode field diameter at a wavelength of 1.55 μm is equal to or greater than 11.5 μm, a cutoff wavelength is equal to or less than 1.53 μm, a bending loss at a bending radius of 30 mm and a wavelength of 1.625 μm is equal to or less than 2.0 dB/100 turns, and a delay time of transmission light per unit length at a wavelength of 1.55 μm is equal to or less than 4.876 μs/km.
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公开(公告)号：US10955622B2
公开(公告)日：2021-03-23
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.
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公开(公告)号：US10585235B2
公开(公告)日：2020-03-10
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.
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公开(公告)号：US20180052278A1
公开(公告)日：2018-02-22
申请号：US15556536
申请日：2016-03-18
Applicant: NIPPON TELEGRAPH AND TELEPHONE CORPORATION
Inventor： Takashi Matsui , Kyozo Tsujikawa , Fumihiko Yamamoto , Nobutomo Hanzawa
Abstract: An object is to provide a beam propagating method capable of satisfying desired output power and a desired propagation distance and a required condition of beam quality and a method of designing an optical fiber designing the structure of an optical fiber. According to the present invention, an effective core cross-sectional area Aeff is calculated based on desired specification values and, by appropriately adjusting the structure of an optical fiber satisfying the effective core cross-sectional area and the number of modes to be propagated, the structure of the optical fiber is determined. In this way, by controlling the excitation ratio of a high-order mode at the time of coupling laser light in the optical fiber designed as above, light of high-output laser can be propagated a long distance with the beam quality maintained.
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Patent Agency Ranking
公开(公告)号：US12181707B2
公开(公告)日：2024-12-31
申请号：US18020539
申请日：2020-08-12
Applicant: NIPPON TELEGRAPH AND TELEPHONE CORPORATION
Inventor： Takashi Matsui , Kazuhide Nakajima , Taiji Sakamoto , Yuto Sagae
Abstract: The present invention is to provide a multi-core optical fiber that can expand its transmission wavelength band, and extend its transmission distance by reducing crosstalk, and also provide a method for designing the multi-core optical fiber. A multi-core optical fiber according to the present invention includes: four cores that are arranged in a square lattice pattern in a longitudinal direction; and a cladding region that is formed around the outer peripheral portions of the cores and has a lower refractive index than the cores, the absolute value of the relative refractive index difference between the cores and the cladding region being represented by A. In the multi-core optical fiber, the diameter of the cladding region is 125+1 μm, the cutoff wavelength is 1.45 μm or shorter, the mode field diameter MFD at a wavelength of 1.55 μm is 9.5 to 10.0 μm, the bending loss at a wavelength of 1.625 μm and with a bending radius of 30 mm is 0.1 dB/100 turns or smaller, and the inter-core crosstalk at the wavelength of 1.625 μm is −47 dB/km or smaller.
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公开(公告)号：US20240181099A1
公开(公告)日：2024-06-06
申请号：US18279424
申请日：2021-03-03
Applicant: Nippon Telegraph and Telephone Corporation
Inventor： Tomohiro TANIGUCHI , Satoshi Narikawa , Ayako IWAKI , Takahito KIRIHARA , Kazuhide Nakajima , Takashi Matsui , Nobutomo HANZAWA , Yuto SAGAE , Chisato Fukai
CPC classification number: A61L2/10 , A61L2/26 , G02B6/4204 , G02B6/4249 , A61L2202/11
Abstract: An object of the present invention is to provide an ultraviolet light irradiation system and an ultraviolet light irradiation method, each of which is capable of reducing deterioration over time of transmission loss characteristics of an optical fiber due to ultraviolet rays and preventing a decrease in ultraviolet ray irradiation power.
An ultraviolet light irradiation system 301 according to the present invention includes: an ultraviolet light source unit 11 configured to generate ultraviolet rays; and N irradiation units 13 each configured to irradiate a desired location Ar with ultraviolet rays, N being a natural number, wherein a propagation section 50 and a supply section 51 are provided between the ultraviolet light source unit 11 and the irradiation units 13, the ultraviolet ray generated by the ultraviolet light source unit 11 is propagated by space-division multiplexing in the propagation section 50, and the ultraviolet rays subjected to space-division multiplexing in the propagation section 50 are multiplexed and propagated to the irradiation units 13 through a single-core optical fiber in the supply section 51.-
8.发明公开公开(公告)号：US20240118486A1
公开(公告)日：2024-04-11
申请号：US18392976
申请日：2023-12-21
Applicant: Nippon Telegraph and Telephone Corporation
Inventor： Takashi Matsui , Kazuhide Nakajima
CPC classification number: G02B6/02042 , G02B27/0012
Abstract: It is an object of the present invention to provide a multicore optical fiber, a design method for the multicore optical fiber and an optical transmission method using the multicore optical fiber including four cores having a standard cladding diameter of 125±1 μm for an existing single mode optical fiber covering several thousands of kilometers of transmission. The multicore optical fiber according to the present invention disposes two-stage claddings with different refractive indices around each core, and designates as a predetermined range, a core radius a1, a radius a2 of a first cladding region surrounding each core, specific refractive index Δ1 relative to the core of the first cladding region and a specific refractive index Δ2 relative to the core of a second cladding region including four cores and the first cladding region.
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公开(公告)号：US10539784B2
公开(公告)日：2020-01-21
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.
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公开(公告)号：US09075185B2
公开(公告)日：2015-07-07
申请号：US13754963
申请日：2013-01-31
Inventor： Naomi Kumano , Iwao Shimotakahara , Ryuichi Sugizaki , Takeshi Yagi , Tomoya Shimizu , Takashi Matsui , Yukihiro Goto , Toshio Kurashima , Kazuhide Nakajima
CPC classification number: G02B6/032 , G02B6/02333 , G02B6/02366 , G02B6/03627
Abstract: A hole-assisted optical fiber includes a core portion and a cladding portion that includes an inner cladding layer, an outer cladding layer, and holes formed around the core portion. A diameter of the core portion is 3 μm to 9.8 μm, a relative refractive index difference of the core portion relative to the outer cladding layer is 0.11% to 0.45%, an outside diameter of the inner cladding layer is 53 μm or less, a relative refractive index difference of the inner cladding layer relative to the outer cladding layer is a negative value, −0.30% or more, a diameter of each hole is 2.4 μm to 4.0 μm, a hole occupancy rate is 17% to 48%, a bending loss at a wavelength of 1625 nm when bent at a radius of 5 mm is 1 dB/turn or less, and a cut-off wavelength is 1550 nm or less.
Abstract translation: 空穴辅助光纤包括芯部和包括内包层，外包层和形成在芯部周围的孔的包层部分。 芯部的直径为3μm〜9.8μm，芯部相对于外包层的相对折射率差为0.11〜0.45％，内包层的外径为53μm以下， 内包层相对于外包层的相对折射率差为负值-0.30％以上，各孔的直径为2.4μm〜4.0μm，孔占有率为17〜48％，a 以5mm的半径弯曲时，波长1625nm处的弯曲损耗为1dB /匝以下，截止波长为1550nm以下。
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