Patents by Inventor Yutaka Miyamoto

Yutaka Miyamoto has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Publication number: 20220149974
    Abstract: A receiver convolutes each of a real component and an imaginary component of each polarization of a polarization-multiplexed reception signal with an impulse response for compensating for frequency characteristics of the receiver and a complex impulse response for wavelength dispersion compensation, and generates, as input signals, the convoluted real component and imaginary component of each polarization and phase conjugations thereof, for each polarization.
    Type: Application
    Filed: January 31, 2020
    Publication date: May 12, 2022
    Applicant: NIPPON TELEGRAPH AND TELEPHONE CORPORATION
    Inventors: Takayuki KOBAYASHI, Masanori NAKAMURA, Fukutaro HAMAOKA, Yutaka MIYAMOTO
  • Patent number: 11315804
    Abstract: A manufacturing method of a mounting structure, the method including a step of preparing a mounting member including a first circuit member and a plurality of second circuit members placed on the first circuit member; a disposing step of disposing a thermosetting sheet and a thermoplastic sheet on the mounting member, with the thermosetting sheet interposed between the thermoplastic sheet and the first circuit member; a first sealing step of pressing a stack of the thermosetting sheet and the thermoplastic sheet against the first circuit member, and heating the stack, to seal the second circuit members and to cure the thermosetting sheet into a first cured layer; a removal step of removing the thermoplastic sheet from the first cured layer; and a coating film formation step of forming a coating film on the first cured layer, after the removal step.
    Type: Grant
    Filed: December 13, 2018
    Date of Patent: April 26, 2022
    Assignee: NAGASE CHEMTEX CORPORATION
    Inventors: Eiichi Nomura, Yutaka Miyamoto, Takayuki Hashimoto
  • Publication number: 20220120960
    Abstract: An amplification fiber includes a core which is doped with an erbium ion and a cladding which surrounds the core and has a refractive index lower than a refractive index of the core, and a relative refractive index difference ?n51 between the core and the cladding is not more than a smaller one of values of a relative refractive index difference ?n1 expressed as a predetermined expression related to a radius a of the core and a relative refractive index difference ?n2 expressed as a predetermined expression related to the radius a of the core.
    Type: Application
    Filed: January 30, 2020
    Publication date: April 21, 2022
    Inventors: Hirotaka ONO, Yutaka MIYAMOTO
  • Patent number: 11283527
    Abstract: An optical transmission system includes an optical transmitter and an optical receiver. The optical transmitter includes a low speed signal generation unit configured to generate, based on an input signal of a transmission data sequence and a signal obtained by cyclically shifting a spectrum of the input signal, a plurality of low speed signals, a high speed signal generation unit configured to digital-to-analog convert and synthesize the plurality of low speed signals to generate a high speed signal, and an optical modulation unit configured to transmit an optical signal obtained by modulation of the high speed signal to a transmission path.
    Type: Grant
    Filed: December 4, 2019
    Date of Patent: March 22, 2022
    Assignee: NIPPON TELEGRAPH AND TELEPHONE CORPORATION
    Inventors: Masanori Nakamura, Fukutaro Hamaoka, Hiroshi Yamazaki, Munehiko Nagatani, Takayuki Kobayashi, Yutaka Miyamoto
  • Publication number: 20220045759
    Abstract: An optical repeater in an MDM optical transmission system prevents a signal-to-noise ratio (SNR) from deteriorating due to a loss of a mode demultiplexer. The optical repeater in the MDM optical transmission system is configured to include at least one multimode optical amplifier, a mode demultiplexer, a mode multiplexer, and variable optical attenuators. One of the multimode optical amplifiers is disposed on the input side of the mode demultiplexer.
    Type: Application
    Filed: December 3, 2019
    Publication date: February 10, 2022
    Inventors: Hirotaka Ono, Koki Shibahara, Takayuki Mizuno, Yutaka Miyamoto
  • Publication number: 20220029707
    Abstract: An optical transmission system includes an optical transmitter and an optical receiver. The optical transmitter includes a low speed signal generation unit configured to generate, based on an input signal of a transmission data sequence and a signal obtained by cyclically shifting a spectrum of the input signal, a plurality of low speed signals, a high speed signal generation unit configured to digital-to-analog convert and synthesize the plurality of low speed signals to generate a high speed signal, and an optical modulation unit configured to transmit an optical signal obtained by modulation of the high speed signal to a transmission path.
    Type: Application
    Filed: December 4, 2019
    Publication date: January 27, 2022
    Applicant: NIPPON TELEGRAPH AND TELEPHONE CORPORATION
    Inventors: Masanori NAKAMURA, Fukutaro HAMAOKA, Hiroshi YAMAZAKI, Munehiko NAGATANI, Takayuki KOBAYASHI, Yutaka MIYAMOTO
  • Publication number: 20220014301
    Abstract: When a first connection number of a b-th output port in an a-th wavelength selective switch connected to paths in one side out of a Drop side and an Add side is expressed by f(a, b, k), and a second connection number of a d-th output port in a c-th wavelength selective switch connected to paths in the other side out of the Drop side and the Add side is expressed by g(c, d, k), f(a, b, k)?g(c, d, k).
    Type: Application
    Filed: November 13, 2019
    Publication date: January 13, 2022
    Applicant: NIPPON TELEGRAPH AND TELEPHONE CORPORATION
    Inventors: Kazunori SENOO, Kenya SUZUKI, Keita YAMAGUCHI, Takayuki MIZUNO, Hirotaka ONO, Toshikazu HASHIMOTO, Yutaka MIYAMOTO
  • Patent number: 11194219
    Abstract: An optical modulator according to embodiments includes a first MZI and a second MZI each including a first optical coupler that splits CW light into two, a second optical coupler that couples the CW light split by the first optical coupler and outputs the CW light, and a bias electrode that adjusts a phase of the CW light split by the first optical coupler, a third optical coupler that couples outputs of the first MZI and the second MZI with at a predetermined ratio and outputs the light, and a bias adjustment circuit that adjusts an output voltage of a bias power supply applied to a bias electrode so that an optical path length difference between the CW light beams split by the first optical coupler is a predetermined times a carrier wavelength under a condition that an output of a differential output amplifier is a zero level, in accordance with an operating mode of the own apparatus.
    Type: Grant
    Filed: March 19, 2019
    Date of Patent: December 7, 2021
    Assignee: NIPPON TELEGRAPH AND TELEPHONE CORPORATION
    Inventors: Hiroto Kawakami, Hiroshi Yamazaki, Yutaka Miyamoto
  • Publication number: 20210376924
    Abstract: A crosstalk estimation system includes: a light source unit that generates a polarization-multiplexed light, which is a polarized light having multiplexed polarizations, of each wavelength in a sideband of a modulated signal and emits the polarization-multiplexed light of each wavelength; a multiplexer that multiplexes the modulated signal with the polarization-multiplexed light for each core, which is associated with one of the wavelengths; a transmission line that transmits the modulated signal multiplexed with the polarization-multiplexed light of each wavelength through a different core; a separation unit that separates the polarization-multiplexed light from the modulated signal multiplexed with the polarization-multiplexed light for each core; a measurement unit that generates light intensity data on the polarization-multiplexed light of each wavelength; and an estimation unit that estimates a crosstalk between the cores based on a difference in light intensity between the polarization-multiplexed light
    Type: Application
    Filed: August 15, 2019
    Publication date: December 2, 2021
    Applicant: NIPPON TELEGRAPH AND TELEPHONE CORPORATION
    Inventors: Akira ISODA, Takayuki MIZUNO, Koki SHIBAHARA, Takayuki KOBAYASHI, Yutaka MIYAMOTO
  • Publication number: 20210320735
    Abstract: A signal generating device includes a digital signal processing unit, M sub DACs of which an analog bandwidth is fB, M being an integer equal to or greater than 2, a broadband analog signal generating unit configured to generate a broadband analog signal that includes a component of a frequency of (M-1)fB or more by using M analog signals output from the M sub DACs. The digital signal processing unit includes components for generating M original divided signals that correspond to signals obtained by dividing a desired output signal into M portions on a frequency axis and down-converting the portions to the baseband, components for generating M folded divided signals by folding back the M original divided signals on the frequency axis, and a 2M×M filter that takes the original divided signals and the folded divided signals as inputs and outputs M composite signals to be transmitted to the M sub DACs. The 2M×M filter can set a response function independently for each of 2M2 combinations of input and output.
    Type: Application
    Filed: June 24, 2019
    Publication date: October 14, 2021
    Inventors: Hiroshi Yamazaki, Munehiko Nagatani, Hideyuki Nosaka, Masanori Nakamura, Yutaka Miyamoto
  • Publication number: 20210296847
    Abstract: An optical amplifier repeater system includes an optical fiber propagating a light beam in a plurality of propagation modes and an optical amplifier repeater amplifying the light beam propagated through the optical fiber. The optical amplifier repeater includes an optical demultiplexer demultiplexing the light beam in the plurality of propagation modes propagated through the optical fiber into a plurality of single-mode light beams, an optical amplifier amplifying, by simultaneous pumping, intensities of the plurality of single-mode light beams using a light beam generated by one pumping light source, an optical multiplexer multiplexing the plurality of single-mode light beams amplified by the optical amplifier into a light beam in the plurality of propagation modes, and an optical intensity adjusting unit adjusting the intensity of each of the plurality of single-mode light beams at least one of before or after the amplification by the optical amplifier.
    Type: Application
    Filed: July 5, 2019
    Publication date: September 23, 2021
    Applicant: NIPPON TELEGRAPH AND TELEPHONE CORPORATION
    Inventors: Takayuki MIZUNO, Koki SHIBAHARA, Akira ISODA, Takayuki KOBAYASHI, Yutaka MIYAMOTO
  • Patent number: 11108208
    Abstract: An optical amplification system includes: three or more nodes; a multi-core fiber having a plurality of cores, the multi-core fiber being used in at least a partial segment of the connection between the nodes; an amplification light input unit configured to input amplification light to a core of the plurality of cores of the multi-core fiber; an amplification unit configured to amplify communication light transmitted through at least one core of the plurality of cores of the multi-core fiber using the amplification light, the amplification unit being provided in the nodes or between the nodes; and an amplification light coupling unit configured to couple the amplification light input by the amplification light input unit to the amplification unit.
    Type: Grant
    Filed: November 22, 2016
    Date of Patent: August 31, 2021
    Assignee: NIPPON TELEGRAPH AND TELEPHONE CORPORATION
    Inventors: Takuya Oda, Tetsuro Inui, Akira Hirano, Wataru Imajuku, Shoukei Kobayashi, Takafumi Tanaka, Yutaka Miyamoto, Hidehiko Takara
  • Publication number: 20210263214
    Abstract: Provided is a mode equalization filter that reduces a light intensity difference between multiple modes of signal light propagating in a core of a few-mode fiber. The mode equalization filter according to the present invention includes: a collimator lens that collimates the signal light emitted from the few-mode fiber; a partial ND filter including a small dot having small transmittance with respect to the collimated signal light; and condensing lenses that condense the signal light transmitted through the partial ND filter on the few-mode fiber. The small dot having the small transmittance is arranged in a part of the partial ND filter, and the partial ND filter is arranged such that, when the collimated signal light is transmitted, a part of the collimated signal light overlaps with the small dot having the small transmittance.
    Type: Application
    Filed: July 12, 2019
    Publication date: August 26, 2021
    Inventors: Hirotaka Ono, Takayuki Mizuno, Koki Shibahara, Yutaka Miyamoto
  • Patent number: 11101914
    Abstract: An optical transmission system includes a plurality of transmission paths that transmit a mode multiplexing signal, and one or more mode permutation units provided between the transmission paths. The mode permutation unit performs mode permutation to interchange modes to be used between at least some optical signals among respective optical signals of a plurality of types of modes that are multiplexed to the mode multiplexing signal input from the transmission path on an input side, and outputs the mode multiplexing signal subjected to the mode permutation to the transmission path on an output side.
    Type: Grant
    Filed: February 20, 2019
    Date of Patent: August 24, 2021
    Assignee: NIPPON TELEGRAPH AND TELEPHONE CORPORATION
    Inventors: Koki Shibahara, Takayuki Mizuno, Yutaka Miyamoto
  • Publication number: 20210257802
    Abstract: There is provided a multimode optical amplifier that provides gain to a plurality of propagation modes of signal light. The multimode optical amplifier includes a multiplexer that multiplexes the signal light and excitation light; an amplifying fiber which has a core that propagates a predetermined plurality of propagation modes of the signal light and a predetermined plurality of propagation modes of the excitation light, and which provides an individual gain value for each of the predetermined propagation modes of the signal light; a wavelength-flattening filter that maintains a constant gain value for a frequency for all predetermined propagation modes of the signal light; and a mode-flattening filter that maintains the gain value at a constant value for a predetermined propagation mode of the signal light for all predetermined propagation modes of the signal light.
    Type: Application
    Filed: July 12, 2019
    Publication date: August 19, 2021
    Inventors: Hirotaka Ono, Takayuki Mizuno, Koki Shibahara, Yutaka Miyamoto
  • Publication number: 20210218477
    Abstract: A signal receiving apparatus includes at least one signal separating apparatus that separates a specific signal from a plurality of received signals. Each of the at least one signal separating apparatus includes a spatial filtering unit that separates at least one equalized signal and a decision signal outputting unit that generates a first decision signal by deciding the equalized signal and outputs the generated first decision signal. The spatial filtering unit separates the at least one equalized signal by multiplying at least the plurality of received signals among the plurality of received signals and either the first decision signal output from the decision signal outputting unit or a second decision signal output from another signal separating apparatus by predetermined weighting coefficients.
    Type: Application
    Filed: March 10, 2021
    Publication date: July 15, 2021
    Applicant: NIPPON TELEGRAPH AND TELEPHONE CORPORATION
    Inventors: Kohki SHIBAHARA, Takayuki MIZUNO, Akira ISODA, Yutaka MIYAMOTO
  • Publication number: 20210178464
    Abstract: A casting solidification analysis method, which can analyze positions of shrinkage cavities more accurately than in the past, a casting method using the above method, and an electronic program are provided. A following casting solidification analysis method is provided. An amount of expansion/shrinkage for each solidification step length separated by inflection points in a cooling curve is determined, by setting a solid phase ratio at a completion of pouring to 0, setting a solid phase ratio at an end of solidification to 1.0, and determining the expansion/shrinkage amount for the each solidification step length by proportionally distributing the each solidification step length to the total solid phase ratio length.
    Type: Application
    Filed: April 25, 2018
    Publication date: June 17, 2021
    Inventors: Haruki ITOFUJI, Yutaka MIYAMOTO
  • Publication number: 20210159996
    Abstract: An optical node device includes one or more input-side wavelength selection switches, a plurality of output-side wavelength selection switches, and an amplification unit. The input-side wavelength selection switches include a plurality of output ports, separate input light in accordance with a wavelength, and output the separated light from the output port corresponding to an output destination of the separated light. The output-side wavelength selection switches include input ports each receiving the light output from each of the one or more input-side wavelength selection switches, multiplex the light received from the input ports, and output the light. The amplification unit amplifies the light output from each of the output ports of the input-side wavelength selection switches and outputs the amplified light to the output-side wavelength selection switch at the output destination corresponding to the output port.
    Type: Application
    Filed: February 1, 2019
    Publication date: May 27, 2021
    Applicant: NIPPON TELEGRAPH AND TELEPHONE CORPORATION
    Inventors: Hirotaka ONO, Mitsunori FUKUTOKU, Shingo KAWAI, Yutaka MIYAMOTO
  • Patent number: 10985846
    Abstract: A signal receiving apparatus includes at least one signal separating apparatus that separates a specific signal from a plurality of received signals. Each of the at least one signal separating apparatus includes a spatial filtering unit that separates at least one equalized signal and a decision signal outputting unit that generates a first decision signal by deciding the equalized signal and outputs the generated first decision signal. The spatial filtering unit separates the at least one equalized signal by multiplying at least the plurality of received signals among the plurality of received signals and either the first decision signal output from the decision signal outputting unit or a second decision signal output from another signal separating apparatus by predetermined weighting coefficients.
    Type: Grant
    Filed: March 8, 2018
    Date of Patent: April 20, 2021
    Assignee: NIPPON TELEGRAPH AND TELEPHONE CORPORATION
    Inventors: Kohki Shibahara, Takayuki Mizuno, Akira Isoda, Yutaka Miyamoto
  • Publication number: 20210096440
    Abstract: An optical modulator according to embodiments includes a first MZI and a second MZI each including a first optical coupler that splits CW light into two, a second optical coupler that couples the CW light split by the first optical coupler and outputs the CW light, and a bias electrode that adjusts a phase of the CW light split by the first optical coupler, a third optical coupler that couples outputs of the first MZI and the second MZI with at a predetermined ratio and outputs the light, and a bias adjustment circuit that adjusts an output voltage of a bias power supply applied to a bias electrode so that an optical path length difference between the CW light beams split by the first optical coupler is a predetermined times a carrier wavelength under a condition that an output of a differential output amplifier is a zero level, in accordance with an operating mode of the own apparatus.
    Type: Application
    Filed: March 19, 2019
    Publication date: April 1, 2021
    Applicant: NIPPON TELEGRAPH AND TELEPHONE CORPORATION
    Inventors: Hiroto KAWAKAMI, Hiroshi YAMAZAKI, Yutaka MIYAMOTO