-
公开(公告)号：US20220365282A1
公开(公告)日：2022-11-17
申请号：US17764239
申请日：2019-10-08
Applicant: NIPPON TELEGRAPH AND TELEPHONE CORPORATION
Inventor： Yoko YAMASHITA , Masaki WADA , Takashi MATSUI , Kazuhide NAKAJIMA
Abstract: An object of the present invention is to provide a core position recognition method, a connection method, and a connection apparatus that can simplify connection operations, and reduce rotational displacement and positional displacement. The connection apparatus according to the present invention includes a function capable of acquiring the rotation amount of an MCF during the bonding/fixing step. Specifically, the connection apparatus of the present invention uses an MCF with lines drawn on a side surface thereof, thereby recognizing the rotation amount of the MCF from the side surface, and calculating the absolute positions of the cores. The connection apparatus according to the present invention can recognize the absolute position s of the cores from a side image of an MCF in a state in which the MCF has been rotated. By forming a waveguide on a glass substrate serving as a connection destination so as to match the absolute positions of the cores, the rotational and positional displacements of the MCF can be eliminated, thus making it possible to reduce the connection loss.
-
公开(公告)号：US20230163554A1
公开(公告)日：2023-05-25
申请号：US17913097
申请日：2020-03-30
Applicant: NIPPON TELEGRAPH AND TELEPHONE CORPORATION
Inventor： Shinichi AOZASA , Yoko YAMASHITA , Takashi MATSUI , Kazuhide NAKAJIMA , Taiji SAKAMOTO , Nobutomo HANZAWA , Noriyuki ARAKI , Ryota IMADA , Yuto SAGAE
CPC classification number: H01S3/06754 , G02B3/08 , G02B6/32 , H01S3/1608
Abstract: An object of the present disclosure is to implement a clad-excitation rare-earth-added optical fiber amplifier with a high light-to-light conversion efficiency. The present disclosure is an optical fiber amplifier having, in a longitudinal direction of a rare-earth-added optical fiber, a light collection structure that collets an excitation light, which propagates through a clad portion, into a core portion.
-
3.发明申请公开(公告)号：US20210234326A1
公开(公告)日：2021-07-29
申请号：US17266181
申请日：2019-08-06
Applicant: NIPPON TELEGRAPH AND TELEPHONE CORPORATION
Inventor： Yoko YAMASHITA , Masaki WADA , Takashi MATSUI , Kazuhide NAKAJIMA
Abstract: Provided is a differential modal attenuation compensation fiber that has a simple structure and can reduce MDL while eliminating the need for precise alignment work, an optical amplifier, and a transmission line design method. The differential modal attenuation compensation fiber according to the present invention, imparts excess loss to a desired propagation mode by forming a cavity portion or a ring-shaped high refractive index portion in a core of an optical fiber. By forming the cavity portion or the ring-shaped high refractive index portion in a part of the profile of the core, electric field distribution of a particular mode propagating through the fiber can be controlled, and different losses can be imparted to different propagation modes at an interface between the cavity portion or the ring-shaped high refractive index portion and a region not including the cavity portion or the ring-shaped high refractive index portion.
-
公开(公告)号：US20250076568A1
公开(公告)日：2025-03-06
申请号：US18293918
申请日：2021-08-02
Applicant: NIPPON TELEGRAPH AND TELEPHONE CORPORATION
Inventor： Nobutomo HANZAWA , Takayoshi MORI , Takashi MATSUI , Yoko YAMASHITA , Kazuhide NAKAJIMA
IPC: G02B6/02
Abstract: The present disclosure is a photonic crystal fiber in which a plurality of holes are formed in a cladding, having a uniform light refractive index, capable of propagating three modes of a fundamental mode, a first higher-order mode, and a second higher-order mode, wherein the plurality of holes are disposed in a triangular lattice pattern so as to surround a center of the photonic crystal fiber with no hole disposed at the center of the photonic crystal fiber, and the photonic crystal fiber has a ratio d/A of a diameter d of each of the holes to a pitch A between the holes such that a confinement loss of a third higher-order mode at a minimum wavelength within a used wavelength range is 1.0 dB/m or more and a confinement loss at a maximum wavelength is 0.001 dB/km or less.
-
公开(公告)号：US20230324604A1
公开(公告)日：2023-10-12
申请号：US18024559
申请日：2020-09-09
Applicant: NIPPON TELEGRAPH AND TELEPHONE CORPORATION
Inventor： Ryota IMADA , Yoko YAMASHITA , Takashi MATSUI , Taiji SAKAMOTO , Nobutomo HANZAWA , Noriyuki ARAKI , Shinichi AOZASA , Yuto SAGAE , Kazuhide NAKAJIMA
IPC: G02B6/02
CPC classification number: G02B6/02095
Abstract: Provided are an LPFG and an optical transmission system in which a mode conversion amount does not depend on a polarization state and an electric field distribution. The LPFG according to the present invention includes cavity rows (25-1 and 25-2) of cavities 15 periodically arranged in a core region 11 of the few-mode fiber 10 at a position away from a central axis z of the core region 11 in parallel with the central axis z. Each of the cavity rows (25-1 and 25-2) is located at a different position in a longitudinal direction of the few-mode fiber 10 (where the position in a z direction is different), and the cavity rows (25-1 and 25-2) are located at positions shifted by 90° on a cross section of the core region 11 with the center of the cross section of the core region 11 (the intersection of an x-axis and a y-axis) as an origin.
-
Patent Agency Ranking
公开(公告)号：US20240427084A1
公开(公告)日：2024-12-26
申请号：US18701805
申请日：2021-10-28
Applicant: NIPPON TELEGRAPH AND TELEPHONE CORPORATION
Inventor： Yoko YAMASHITA , Takayoshi MORI , Takashi MATSUI , Kazuhide NAKAJIMA
IPC: G02B6/14
Abstract: The present disclosure aims to provide a short optical fiber-type mode converter having small wavelength dependency.
The present disclosure is about a mode converter including a cladding having a constant refractive index, a core having a refractive index higher than the refractive index of the cladding in the cladding, and a refractive index modulation part provided to obliquely cross the core and having a different refractive index from a refractive index of surroundings.-
公开(公告)号：US20240369769A1
公开(公告)日：2024-11-07
申请号：US18573170
申请日：2021-06-28
Applicant: NIPPON TELEGRAPH AND TELEPHONE CORPORATION
Inventor： Yoko YAMASHITA , Takayoshi MORI , Takashi MATSUI , Kazuhide NAKAJIMA
Abstract: An object of the present disclosure is to provide an optical side input/output circuit for allowing light for being input into or output from a side surface of an optical fiber with high efficiency.
The present disclosure is an optical side input/output circuit including: a tap unit in which a tap waveguide is formed for allowing light for propagation through a core of an optical fiber for being input into or output from a side surface of the optical fiber; and a refractive index matching unit, having a refractive index higher than a refractive index of the tap waveguide, on the side surface of the optical fiber where the light is allowed for being input or output by the tap waveguide.-
公开(公告)号：US20230336338A1
公开(公告)日：2023-10-19
申请号：US18009399
申请日：2020-06-11
Applicant: NIPPON TELEGRAPH AND TELEPHONE CORPORATION
Inventor： Yuto SAGAE , Kazuhide NAKAJIMA , Taiji SAKAMOTO , Nobutomo HANZAWA , Takashi MATSUI , Noriyuki ARAKI , Shinichi AOZASA , Ryota IMADA , Yoko YAMASHITA
Abstract: It is an object of the present disclosure to reduce the risk of information exploitation by a malicious third party while allowing communication data to be demodulated in real time. An optical transmission system according to the present disclosure includes a transmitter which transmits an optical signal representing a cryptographic key and an optical signal representing communication data individually, an optical transmission path including a heterogeneous multi-core optical fiber having multiple cores, at least one of which has a different propagation delay time, the optical transmission path transmitting the optical signal representing the cryptographic key using a first core with a smaller delay among the multiple cores and the optical signal representing the communication data using a second core with a greater delay than the first core, and a receiver which individually receives the optical signals representing the cryptographic key and the communication data output from the individual cores of the optical transmission path and demodulates the received communication data on the basis of the received cryptographic key information.
-
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：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.
-
-
-
-
-
-
-
-
-
Search Results
16
records
(took 0.015 seconds)
