-
公开(公告)号:US20230305223A1
公开(公告)日:2023-09-28
申请号:US18019193
申请日:2020-08-05
Applicant: NIPPON TELEGRAPH AND TELEPHONE CORPORATION
Inventor: Yoko YAMASHITA , Kazuhide NAKAJIMA , Takashi MATSUI
CPC classification number: G02B6/0288 , G02B6/3825
Abstract: An object of the present invention is to provide a simple method capable of reducing MDL after construction of a transmission path.
An optical connector 301 is an optical connector including a multimode optical fiber 11, in which a core 20 of the multimode optical fiber 11 includes a plurality of cavities 25 along a central axis. The optical connector 301 further includes a ferrule 12 surrounding the multimode optical fiber 11 and a connector plug 13 serving as a connection with another optical connector. The shape of the optical connector 13 is a shape of a generally used SC connector, FC connector, MT connector, or the like.-
公开(公告)号:US20230302173A1
公开(公告)日:2023-09-28
申请号:US18032495
申请日:2020-10-21
Applicant: NIPPON TELEGRAPH AND TELEPHONE CORPORATION
Inventor: Tomohiro TANIGUCHI , Ayako IWAKI , Kazuhide NAKAJIMA , Nobutomo HANZAWA , Takashi MATSUI , Yuto SAGAE , Chisato FUKAI
CPC classification number: A61L2/10 , A61L2/24 , A61L2202/11 , G02B6/4206
Abstract: In order to solve the above problems, an object of the present invention is to provide an ultraviolet light irradiation system and an ultraviolet light irradiation method with a few transmission losses in an optical fiber.
The ultraviolet light irradiation system 301 includes: a light source unit 11 for injecting transmission infrared light into an optical fiber 50, a wavelength conversion unit 12 for converting the transmission infrared light propagated through the optical fiber 50 into ultraviolet light, and an irradiation unit 13 for irradiating the ultraviolet light on a desired place. The light source unit 11 has a polarization scrambler 11b, and infrared light output from one infrared light source 11a is made to be transmission infrared light by the polarization scrambler 11b.-
公开(公告)号:US20230293741A1
公开(公告)日:2023-09-21
申请号:US18018035
申请日:2020-10-21
Applicant: NIPPON TELEGRAPH AND TELEPHONE CORPORATION
Inventor: Takashi MATSUI , Kazuhide NAKAJIMA , Nobutomo HANZAWA , Yuto SAGAE , Chisato FUKAI , Ayako IWAKI , Tomohiro TANIGUCHI , Kazutaka HARA , Atsuko KAWAKITA
CPC classification number: A61L2/10 , A61L2/24 , A61L2/26 , G02B6/102 , A61L2202/11 , A61L2202/14
Abstract: An object of the present invention is to provide an ultraviolet light irradiation system and a decontamination method that are economical and easy to operate, and that can perform decontamination without any input from a user. In the present invention, an optical fiber or an optical waveguide that radiates ultraviolet light in a lateral direction, the optical fiber or the optical waveguide is built in a sheet shape, and irradiates a surface with the ultraviolet light. Specifically, a material in which a material having a high scattering coefficient is added to the optical fiber is used, a grating is formed in the optical fiber, the optical fiber is given a minute bending with a minute ruggedness, and an arbitrary bending is given on the optical fiber, or the like, thereby achieving side radiation. By such a feature, it has the effect that ultraviolet light decontamination can be performed at all times or at necessary timing for an object touched by an unspecified number of people.
-
公开(公告)号:US20230176284A1
公开(公告)日:2023-06-08
申请号:US17919327
申请日:2020-04-24
Applicant: NIPPON TELEGRAPH AND TELEPHONE CORPORATION
Inventor: Yoko YAMASHITA , Takashi MATSUI , Kazuhide NAKAJIMA
CPC classification number: G02B6/14 , G02B6/1228
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.
-
公开(公告)号:US20230042437A1
公开(公告)日:2023-02-09
申请号:US17791930
申请日:2020-02-19
Applicant: NIPPON TELEGRAPH AND TELEPHONE CORPORATION
Inventor: Yoko YAMASHITA , Kazuhide NAKAJIMA , Takashi MATSUI
IPC: H01S3/067
Abstract: An object of the present disclosure is to allow gain compensation with a simple configuration without adding a new device to the outside. The present disclosure discloses a rare earth doped fiber including a core doped with a rare earth and a cladding region around the core, wherein one or more cavities are provided inside the core, and at least one of the cavities are provided along a longitudinal direction of the rare earth doped fiber.
-
公开(公告)号:US20220214496A1
公开(公告)日:2022-07-07
申请号:US17605758
申请日:2020-04-06
Applicant: NIPPON TELEGRAPH AND TELEPHONE CORPORATION
Inventor: Taiji SAKAMOTO , Kazuhide NAKAJIMA , Masaki WADA , Shinichi AOZASA , Takashi YAMAMOTO
Abstract: An object is to provide a multi-core configuration for acquiring a random mode coupling in a case of an arbitrary core refractive index.
A multi-core optical fiber according to the present invention is an optical fiber in which two or more core regions are arranged in a clad region having a refractive index at a minimum core interval Λ smaller than a refractive index of the cores, a configuration of the cores is that including one propagation mode, and the core configuration and the core interval are adjusted so that an inter-mode coupling coefficient between adjacent cores is within a range from 0.73 to 120 m−1.-
47.
公开(公告)号:US20220003920A1
公开(公告)日:2022-01-06
申请号:US17294892
申请日:2019-11-08
Applicant: NIPPON TELEGRAPH AND TELEPHONE CORPORATION
Inventor: Takashi MATSUI , Kazuhide NAKAJIMA
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.
-
公开(公告)号:US20180341104A1
公开(公告)日:2018-11-29
申请号:US15771040
申请日:2016-11-17
Applicant: NIPPON TELEGRAPH AND TELEPHONE CORPORATION
Inventor: Takashi MATSUI , Kazuhide NAKAJIMA , Kyozo TSUJIKAWA , Fumihiko YAMAMOTO
Abstract: An optical fiber design method according to the present invention is a design method of a photonic crystal fiber having a plurality of holes arranged in the optical fiber along a longitudinal direction, in which a required effective cross-sectional area is calculated from a light wavelength, a transmission distance, and output power 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 a fiber structure (hole diameter and hole interval) corresponding to the effective cross-sectional area is calculated.
-
公开(公告)号:US20250118941A1
公开(公告)日:2025-04-10
申请号:US18832029
申请日:2022-02-03
Applicant: NIPPON TELEGRAPH AND TELEPHONE CORPORATION
Inventor: Ryota IMADA , Taiji SAKAMOTO , Shinichi AOZASA , Kazuhide NAKAJIMA
Abstract: An optical amplifier of the present disclosure includes a rare-earth doped fiber including a plurality of cores, in which a v value of the plurality of cores of the rare-earth doped fiber is less than 2.405, the plurality of cores has a core pitch of a normalized coupling coefficient of 1.0×10−3 or more, and on injection of excitation light into a clad part of the rare-earth doped fiber in a state of being bent at a predetermined bending radius, propagating light in the rare-earth doped fiber is amplified with mode-dependent gain characteristics dependent on the bending radius.
-
公开(公告)号:US20250060213A1
公开(公告)日:2025-02-20
申请号:US18706667
申请日:2022-11-29
Inventor: Nobutomo HANZAWA , Kazuhide NAKAJIMA , Takashi MATSUI , Hideaki MURAYAMA , Ryota WADA , Makito KOBAYAHSI
IPC: G01B11/16
Abstract: The present disclosure is a shape measurement system including: a multi-core optical fiber in which four or more cores are disposed in a part other than the center of a cross section; a strain distribution measurement device configured to measure a strain distribution of each of the cores in a longitudinal direction of the multi-core optical fiber; and an analysis device configured to calculate a shape of the multi-core optical fiber by using the strain distribution of the multi-core optical fiber.
-
-
-
-
-
-
-
-
-