公开(公告)号：US20250008248A1

公开(公告)日：2025-01-02

申请号：US18709754

申请日：2021-11-16

Applicant: NIPPON TELEGRAPH AND TELEPHONE CORPORATION

Inventor： Yasunari TANAKA ,  Takuya KANAI ,  Kazutaka HARA ,  Yumiko SENOO ,  Shin KANEKO ,  Junichi KANI

IPC: H04Q11/00 ,  H04L41/12 ,  H04L43/0864

Abstract: An optical switch having a plurality of ports outputs an optical signal received from a first port that is one of the plurality of ports connected to an optical communication device from a second port that another one of the plurality of ports according to a transmission path of an optical signal. An optical branching part branches an optical signal which has been output from a second port in accordance with a branching ratio. A measurement part measures a round trip time by transmitting and receiving an optical signal to and from an optical communication device through an optical switch, and calculates a transmission distance of the optical signal on the basis of the measured round trip time. An instruction part instructs, the optical branching part, of the branching ratio determined on the basis of the calculated transmission distance.

公开(公告)号：US20230308189A1

公开(公告)日：2023-09-28

申请号：US18017879

申请日：2020-07-29

Applicant: NIPPON TELEGRAPH AND TELEPHONE CORPORATION

Inventor： Ryo IGARASHI ,  Masamichi FUJIWARA ,  Takuya KANAI

IPC: H04B10/80

CPC classification number: H04B10/807

Abstract: There is provided an optical power feeding system including: an optical power feeding unit; and a plurality of drop units configured to be able to receive light from the optical power feeding unit as an input, branch the input light, and output branched light, in which, the optical power feeding unit includes a power-feed light generating unit that outputs power-feed light, and the drop unit includes: an optical splitter that branches the power-feed light into first branch light and second branch light and outputs the second branch light to another drop unit; a photoelectric conversion unit that performs photoelectric conversion of the first branch light; and a branch ratio control unit that is driven by electricity generated by the photoelectric conversion and controls a branch ratio that is a ratio between the first branch light and the second branch light.

公开(公告)号：US20230224034A1

公开(公告)日：2023-07-13

申请号：US17927056

申请日：2020-05-28

Applicant: NIPPON TELEGRAPH AND TELEPHONE CORPORATION

Inventor： Ryo IGARASHI ,  Masamichi FUJIWARA ,  Takuya KANAI

IPC: H04B10/079

CPC classification number: H04B10/07955 ,  H04B10/0797

Abstract: An optical amplification estimation method includes by an excitation light output unit connected to a first end of a first optical transmission line, making excitation light incident on the first optical transmission line, by a monitoring unit connected to the same side as the first end of the first optical transmission line, making monitoring light incident on the first optical transmission line, the monitoring light having a wavelength different from a wavelength of the excitation light, by the monitoring unit, measuring intensity of light incident on the monitoring unit when the excitation light is incident, and intensity of light incident on the monitoring unit when the excitation light is not incident, and by an amplification estimation unit, estimating a gain of an optical signal in the first optical transmission line based on the light intensity measured in the measuring. The first optical transmission line shares a partial optical transmission line with a second optical transmission line used for an optical network unit and an optical line terminal to transmit and receive an optical signal to and from each other.

公开(公告)号：US20220368428A1

公开(公告)日：2022-11-17

申请号：US17623968

申请日：2019-07-01

Applicant: NIPPON TELEGRAPH AND TELEPHONE CORPORATION

Inventor： Ryo IGARASHI ,  Takuya KANAI ,  Masamichi FUJIWARA ,  Junichi KANI

IPC: H04B10/67 ,  H04B10/61

Abstract: An optical reception device including: a wavelength selection unit configured to split an optical signal amplified by an optical amplifier into different paths according to wavelengths by using a wavelength multiplexer/demultiplexer, and control a passage state of a passage target optical switch through which the optical signal is to be passed, out of a plurality of optical switches provided on the respective paths, to select an optical signal of a path where the optical signal entered and output the optical signal to a receiver; and a wavelength detection unit configured to detect the wavelength of an optical signal by using each of a plurality of optical detectors, determine the passage target optical switch based on a detection result, and output, to the determined passage target optical switch, a control signal for controlling the passage target optical switch so as to enter the passage state, the optical detectors being respectively provided on different paths that are different from the paths on which the plurality of optical switches are provided and that respectively correspond to wavelengths into which the optical signal is split by a wavelength multiplexer/demultiplexer.

公开(公告)号：US20220113478A1

公开(公告)日：2022-04-14

申请号：US17427866

申请日：2020-01-31

Applicant: NIPPON TELEGRAPH AND TELEPHONE CORPORATION

Inventor： Takuya KANAI ,  Takeshi IMAI ,  Yumiko SENOO ,  Kota ASAKA

IPC: G02B6/42 ,  H01L31/0232

Abstract: A wavelength-selective optical reception device includes a photoreceptor (21) that converts optical signals (201) into electric signals and outputs the electric signals, a base (31) on which the photoreceptor (21) is provided, a housing (41) that is mounted on the base (31) and surrounds the photoreceptor (21) along with the base (31), and that is provided with a window (51) to pass optical signals (203) including the optical signals (201) and including optical signals (202) of a wavelength different from a first wavelength of the optical signals (201) and a window (52) to pass the optical signals (202), and an optical filter (61) that is disposed inside the housing between the window (51) and the photoreceptor (21) along the optical axis (205) of the optical signals (203), and that outputs, out of the optical signals (203) that enter thereto, the optical signals (201) toward the photoreceptor (21), and reflects the optical signals (202) toward a near side in a direction of travel of the optical signals (203).

公开(公告)号：US20250088281A1

公开(公告)日：2025-03-13

申请号：US18721627

申请日：2021-12-20

Applicant: NIPPON TELEGRAPH AND TELEPHONE CORPORATION

Inventor： Takuya KANAI ,  Kazutaka HARA ,  Shin KANEKO

IPC: H04B10/54

Abstract: An optical node device includes a modulation amplitude correction unit which generates correction information for correcting an amplitude of a modulated signal based on a control signal so that a superimposition ratio when superimposing the control signal for controlling a subscriber device on an optical signal becomes a desired superimposition ratio; a driver which converts the control signal input from the outside into a modulated signal, and adjusts the amplitude of the modulated signal, using the correction information generated by the modulation amplitude correction unit; and a superimposing unit which superimposes the modulated signal adjusted by the driver on the optical signal.

公开(公告)号：US20250016481A1

公开(公告)日：2025-01-09

申请号：US18710996

申请日：2021-11-25

Applicant: NIPPON TELEGRAPH AND TELEPHONE CORPORATION

Inventor： Naotaka SHIBATA ,  Shin KANEKO ,  Takuya KANAI

IPC: H04Q11/00 ,  H04B10/27

Abstract: An optical communication system including an optical switch that is connected to a plurality of optical transmission lines and outputs an optical signal input from any of the optical transmission lines to another optical transmission line, and a transfer unit configured to convert simplex transmission into duplex transmission or converts duplex transmission into simplex transmission between a subscriber device and the optical switch or between a first port of the optical switch to which the subscriber device is directly or indirectly connected and a second port opposite to the first port, and transfers the optical signal so as not to cause interference between uplink and downlink.

公开(公告)号：US20250007610A1

公开(公告)日：2025-01-02

申请号：US18709730

申请日：2021-11-18

Applicant: NIPPON TELEGRAPH AND TELEPHONE CORPORATION

Inventor： Shin KANEKO ,  Takuya KANAI ,  Naotaka SHIBATA ,  Junichi KANI

IPC: H04B10/27 ,  H04B10/294

Abstract: An optical communication system including a subscriber device that performs optical connection with other subscriber device by End-End, and a management control device that controls each subscriber device, wherein the subscriber device includes an optical signal transmission unit configured to transmit an optical signal, an optical signal reception unit configured to receive an optical signal transmitted from the other subscriber device, and an output function unit configured to output an optical signal outputted by the optical signal transmission unit to an optical transmission line regardless of a wavelength and outputs an optical signal inputted from the optical transmission line to the optical signal reception unit regardless of the wavelength, and the management control device allocates wavelengths so that a transmission wavelength of the subscriber device becomes a reception wavelength of the other subscriber device and a transmission wavelength of the other subscriber device becomes a reception wavelength of the subscriber device.

公开(公告)号：US20240388821A1

公开(公告)日：2024-11-21

申请号：US18691749

申请日：2021-09-16

Applicant: NIPPON TELEGRAPH AND TELEPHONE CORPORATION

Inventor： Shin KANEKO ,  Takuya KANAI ,  Kazutaka HARA ,  Junichi KANI

IPC: H04Q11/00 ,  H04J14/02 ,  H04L41/34

Abstract: An optical communication system including: a management control device that manages communication between one or more first subscriber devices and one or more second subscriber devices that are provided at counterpart locations of the one or more first subscriber devices, in which the management control device includes a control signal generation unit that generates a control signal that is transmitted to the one or more first subscriber devices and used for management and control, and an optical transmission unit that converts the control signal generated by the control signal generation unit into an optical signal with a wavelength that is different from a wavelength of a main signal transmitted by the one or more second subscriber devices that perform communication with the one or more first subscriber devices and transmits the optical signal, and the optical communication system includes an optical multiplexing unit that is provided on a communication path between the one or more first subscriber devices and the one or more second subscriber devices and multiplexes the main signal transmitted by the one or more second subscriber devices with the optical signal transmitted from the optical transmission unit.

公开(公告)号：US20230291484A1

公开(公告)日：2023-09-14

申请号：US18016704

申请日：2020-07-29

Applicant: NIPPON TELEGRAPH AND TELEPHONE CORPORATION

Inventor： Ryo IGARASHI ,  Masamichi FUJIWARA ,  Takuya KANAI

IPC: H04B10/61 ,  H04B10/272

CPC classification number: H04B10/614 ,  H04B10/272

Abstract: A branch ratio setting system includes: a branch ratio control unit; and a plurality of drop units configured to be able to receive an optical signal from the branch ratio control unit, and configured to branch and output the received optical signal, and the branch ratio control unit outputs light to the plurality of drop units via an optical fiber to measure characteristics of the optical fiber, and outputs a branch ratio determination signal to each of the plurality of drop units via the optical fiber based on the measured characteristics of the optical fiber, and the drop unit includes an optical splitter connected to the optical fiber and having a variable branch ratio and a branch ratio setting unit that sets the branch ratio of the optical splitter based on the branch ratio determination signal input via the optical fiber.