Patents by Inventor Takeshi Hoshida
Takeshi Hoshida 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).
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Publication number: 20210092498Abstract: An optical network device receives an optical signal, to which polarization information is added, from a transmitter via a transmission line. The receiver generates electric-field-information signal of the optical signal. The processor acquires, for respective polarization rotation amounts, the electric-field-information signal during a period specified by the polarization information. The processor calculates, for respective polarization rotation amounts and based on the electric-field-information signal, evaluation values corresponding to powers of the optical signal at a plurality of positions on the transmission line. The processor calculates, for respective positions, variations in the evaluation values corresponding to the polarization rotation amounts.Type: ApplicationFiled: July 24, 2020Publication date: March 25, 2021Applicant: FUJITSU LIMITEDInventors: KAZUYUKI TAJIMA, Takahito Tanimura, Setsuo Yoshida, Takeshi Hoshida
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Patent number: 10955727Abstract: A wavelength converter includes an excitation light source outputting excitation light, a beam splitter receiving an input of the excitation light and an input of the optical signal and to divide both the inputted excitation light and the inputted optical signal into a first polarization component and a second polarization component, a non-linear optical fiber as a non-polarization-maintaining fiber, an accommodation section securing and accommodating the non-linear optical fiber, a first collimator lens disposed between the beam splitter and a first end of the non-linear optical fiber, and a second collimator lens disposed between the beam splitter and a second end of the non-linear optical fiber, wherein the optical signal is inputted to the beam splitter from a direction different from the input of the excitation light.Type: GrantFiled: February 4, 2020Date of Patent: March 23, 2021Assignee: FUJITSU LIMITEDInventors: Goji Nakagawa, Tomoyuki Kato, Takeshi Hoshida, Masaaki Kawai
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Patent number: 10948802Abstract: A wavelength converter includes a first phase modulator configured to perform phase modulation on pump light in accordance with a first phase modulation signal, a second phase modulator configured to perform phase modulation on signal light in accordance with a second phase modulation signal, a wavelength converter configured to multiplex the signal light having undergone the phase modulation with the pump light having undergone the phase modulation, the wavelength converter configured to perform wavelength conversion on the signal light in accordance with the pump light, a detector configured to detect a modulation component from the signal light having undergone the phase modulation and the pump light having undergone the phase modulation, and a generator configured to generate the first phase modulation signal and the second phase modulation signal so as to minimize the detected modulation component.Type: GrantFiled: January 14, 2020Date of Patent: March 16, 2021Assignee: FUJITSU LIMITEDInventors: Goji Nakagawa, Tomoyuki Kato, Takeshi Hoshida
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Patent number: 10873410Abstract: There is provided a reception device including a receiver configured to receive a wavelength-multiplexed optical signal so as to generate a wavelength-multiplexed signal, a filter configured to pass through the wavelength-multiplexed signal having a specific wavelength and an adjacent wavelength to the specific wavelength from the wavelength-multiplexed signal, and a processor configured to detect a specific signal having the specific wavelength from the wavelength-multiplexed signal having the passed through wavelengths by the filter, and detect a first supervisory control signal having the specific wavelength and a second supervisory control signal having the adjacent wavelength from the wavelength-multiplexed signal having the passed through wavelengths by the filter.Type: GrantFiled: February 20, 2018Date of Patent: December 22, 2020Assignee: FUJITSU LIMITEDInventors: Yi Ge, Takeshi Hoshida, Hisao Nakashima, Tomofumi Oyama, Yuichi Akiyama
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Patent number: 10862592Abstract: An optical receiver includes, a first converting circuit that converts an optical signal into an electric signal, a plurality of common circuits, each of which has a same circuit configuration and performs a digital signal processing on the electric signal, and a processor that selects and operates one or more common circuits from among the plurality of common circuits according to a transmission method.Type: GrantFiled: July 31, 2018Date of Patent: December 8, 2020Assignee: FUJITSU LIMITEDInventors: Hisao Nakashima, Takeshi Hoshida
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Publication number: 20200379180Abstract: A method includes multiplexing signal light of first polarization and excitation light, and multiplexing signal light of second polarization, which is perpendicular to the first polarization, and the excitation light, modulating the signal light of the first polarization before the wavelength conversion, and reducing a modulation component in signal light after wavelength conversion, modulating the signal light of the second polarization before the wavelength conversion, and reducing the modulation component in the signal light after the wavelength conversion, and multiplexing the signal light of the first polarization after the wavelength conversion and the signal light of the second polarization after the wavelength conversion.Type: ApplicationFiled: May 27, 2020Publication date: December 3, 2020Inventors: Tomohiro YAMAUCHI, Tomoyuki KATO, Goji NAKAGAWA, Takeshi HOSHIDA
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Patent number: 10853719Abstract: A data collecting device includes a receiver configured to receive an optical signal; an optical-to-electrical converter configured to convert the optical signal received by the receiver into an electrical signal; an analog-to-digital converter configured to convert the electrical signal into a digital signal; a data reducing circuit configured to reduce the digital signal output from the analog-to-digital converter; and a transmitter configured to transmit, to a managing device that manages the data collecting device, a signal obtained by reducing the digital signal by the data reducing circuit.Type: GrantFiled: December 2, 2016Date of Patent: December 1, 2020Assignee: FUJITSU LIMITEDInventors: Takahito Tanimura, Takeshi Hoshida
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Patent number: 10797799Abstract: An optical transmission apparatus includes a wavelength variable filter whose transmission light wavelength is variable; a receiver that receives light, the light being sent from another optical transmission apparatus and passing through the wavelength variable filter; a transmitter that sends to the another optical transmission apparatus, a utilization permission request for a second wavelength corresponding to a first wavelength of the light received by the receiver, the transmitter sending the utilization permission request as light of the second wavelength and in a form of a tone signal of a predetermined frequency; and a controller that, when receiving from the another optical transmission apparatus, a utilization permission notification of the second wavelength for a sender of the utilization permission request, configures a wavelength of a main signal to the second wavelength, the main signal being sent from the transmitter to the another optical transmission apparatus.Type: GrantFiled: October 25, 2018Date of Patent: October 6, 2020Assignee: FUJITSU LIMITEDInventors: Goji Nakagawa, Kyosuke Sone, Yoshio Hirose, Takeshi Hoshida, Setsuo Yoshida
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Publication number: 20200264492Abstract: A wavelength converter includes an excitation light source outputting excitation light, a beam splitter receiving an input of the excitation light and an input of the optical signal and to divide both the inputted excitation light and the inputted optical signal into a first polarization component and a second polarization component, a non-linear optical fiber as a non-polarization-maintaining fiber, an accommodation section securing and accommodating the non-linear optical fiber, a first collimator lens disposed between the beam splitter and a first end of the non-linear optical fiber, and a second collimator lens disposed between the beam splitter and a second end of the non-linear optical fiber, wherein the optical signal is inputted to the beam splitter from a direction different from the input of the excitation light.Type: ApplicationFiled: February 4, 2020Publication date: August 20, 2020Applicant: FUJITSU LIMITEDInventors: GOJI NAKAGAWA, Tomoyuki Kato, Takeshi Hoshida, Masaaki Kawai
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Patent number: 10749604Abstract: A compensating device includes at least one detector configured to detect intensity variation of the optical signal, at least one filter configured to extract a band where most of the optical phase distortion is generated from a component of the intensity variation of the optical signal, a control circuit configured to generate, based on the extraction with the at least one filter, a compensation signal exhibiting temporal intensity variation of the input optical signal, at least one compensation signal light source configured to output, based on the compensation signal of a controller, a compensation signal light exhibiting intensity variation in opposite phase to the temporal intensity variation of the input optical signal and having a different wavelength from a wavelength of the optical signal and an optical multiplexer configured to output to a transmission path a signal light formed by combining the optical signal and the compensation signal light.Type: GrantFiled: June 28, 2019Date of Patent: August 18, 2020Assignee: FUJITSU LIMITEDInventors: Tomoyuki Kato, Takeshi Hoshida
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Publication number: 20200241384Abstract: A wavelength converter includes a first phase modulator configured to perform phase modulation on pump light in accordance with a first phase modulation signal, a second phase modulator configured to perform phase modulation on signal light in accordance with a second phase modulation signal, a wavelength converter configured to multiplex the signal light having undergone the phase modulation with the pump light having undergone the phase modulation, the wavelength converter configured to perform wavelength conversion on the signal light in accordance with the pump light, a detector configured to detect a modulation component from the signal light having undergone the phase modulation and the pump light having undergone the phase modulation, and a generator configured to generate the first phase modulation signal and the second phase modulation signal so as to minimize the detected modulation component.Type: ApplicationFiled: January 14, 2020Publication date: July 30, 2020Applicant: FUJITSU LIMITEDInventors: GOJI NAKAGAWA, Tomoyuki Kato, Takeshi Hoshida
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Patent number: 10720992Abstract: There is provided a transmission apparatus including a transmitter configured to modulate a signal to a first signal having a first wavelength and a signal to a second signal having a second wavelength, and transmit the first signal and the second signal to a transmission line so that the second signal is varied in accordance with variation in an amount of cross phase modulation of the first signal passing through each position on the transmission line, and a signal processor configured to include at least one of a logic device and a processor, and configured to add an amount of chromatic dispersion at which a remaining amount of chromatic dispersion of the first wavelength at a certain position on the transmission line is equal to zero to the first wavelength in the transmission of the first signal and the second signal.Type: GrantFiled: June 19, 2018Date of Patent: July 21, 2020Assignee: FUJITSU LIMITEDInventors: Takahito Tanimura, Takeshi Hoshida, Shigeki Watanabe, Tomoyuki Kato
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Publication number: 20200200973Abstract: A device includes a first excitation light source that emits first excitation light, a second excitation light source that emits second excitation light, a wavelength converter that converts signal light of a first wavelength into signal light of a second wavelength according to the first excitation light, and a measurer that measures a frequency difference between the first excitation light and the second excitation light, wherein when an abnormality of the first excitation light is detected, the second excitation light source is adjusted so that a frequency of the second excitation light is aligned with a frequency of the first excitation light before the abnormality detection, based on the frequency difference before the abnormality detection, and the wavelength converter converts the signal light of the first wavelength into the signal light of the second wavelength according to the second excitation light, after adjusting the frequency of the second excitation light.Type: ApplicationFiled: December 6, 2019Publication date: June 25, 2020Applicant: FUJITSU LIMITEDInventors: Tomohiro YAMAUCHI, Takeshi Hoshida, Shingo Hara, Hiroki SATOU
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Publication number: 20200153504Abstract: A communication device used in an optical communication system, the communication device includes a mode change over device configured to switch between a learning mode for learning a normal state of an optical transmission path before operation and a monitoring mode for monitoring a state of the optical transmission path during operation, an anomaly detector configured to detect an anomaly of the optical transmission path using a prediction model determined by the learning mode when the monitoring mode is selected, and a data writer configured to extract waveform data including information related to the anomaly to output the extracted waveform data to an outside when the anomaly is detected.Type: ApplicationFiled: November 11, 2019Publication date: May 14, 2020Applicant: FUJITSU LIMITEDInventors: Takahito Tanimura, Takeshi Hoshida
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Publication number: 20200059313Abstract: A transmission device that transmits wavelength multiplexed light to a transmission line, the transmission device includes a first multiplexer configured to multiplex light of a wavelength of a first wavelength band and output first multiplexed light, a second multiplexer configured to multiplex the light of the wavelength of the first wavelength band and output second multiplexed light, a wavelength converter configured to convert the second multiplexed light into light of a wavelength of a second wavelength band different from the first wavelength band, and a third multiplexer configured to multiplex the second multiplexed light converted to the light of the wavelength of the second wavelength band and the first multiplexed light and output the wavelength multiplexed light.Type: ApplicationFiled: October 23, 2019Publication date: February 20, 2020Applicant: FUJITSU LIMITEDInventors: Tomoyuki Kato, Takeshi Hoshida, Tomoaki Takeyama
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Patent number: 10567077Abstract: Provided is an imbalance compensation device that compensates for an imbalance between an in-phase component and a quadrature-phase component of a signal, the imbalance compensation device including: an extracting unit that extracts a signal component in an upper sideband or a signal component in a lower sideband from the signal; a measuring unit that measures power of the signal component in the upper sideband or the signal component in the lower sideband extracted by the extracting unit; and an adjusting unit that adjusts a parameter related to the imbalance, in accordance with the power measured by the measuring unit.Type: GrantFiled: March 6, 2018Date of Patent: February 18, 2020Assignee: FUJITSU LIMITEDInventors: Tomofumi Oyama, Takeshi Hoshida, Yoshitaka Nomura, Hisao Nakashima
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Patent number: 10554325Abstract: A transmitter transmitting a polarization multiplexed optical signal, includes: a light source; a generating unit configured to split a light of the light source into first and second polarized lights, optically modulate the first and second polarized lights based on an electric data signal, and multiplex the first polarized light optically-modulated and the second polarized light optically-modulated to generate the polarization multiplexed optical signal; and a coupling unit configured to couple a first reference light having a frequency different from a frequency of the light of the light source with the first polarized light and couple a second reference light having a frequency different from the frequency of the light of the light source with the second polarized light, wherein the first reference light and the second reference light have different frequencies.Type: GrantFiled: August 30, 2018Date of Patent: February 4, 2020Assignee: FUJITSU LIMITEDInventors: Tomohiro Yamauchi, Takahito Tanimura, Takeshi Hoshida, Rafael Puerta Ramirez
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Publication number: 20200036446Abstract: An optical transmission device includes: a frontend circuit, a converter, an equalizer, a recovery, spectrum detector a correction information generator, and a transmitter. The frontend circuit converts an optical signal received via an optical network into an electric signal. The converter converts an output signal of the frontend circuit into a digital signal. The equalizer equalizes the digital signal or a second digital signal that is generated based on the digital signal. The recovery recovers a symbol from an output signal of the equalizer. The spectrum detector detects a reception spectrum of the optical signal based on the digital signal or the second digital signal. The correction information generator generates, according to the reception spectrum, correction information for correcting a shape of a transmission spectrum of the optical signal. The transmitter transmits the correction information to the source device.Type: ApplicationFiled: July 9, 2019Publication date: January 30, 2020Applicant: FUJITSU LIMITEDInventors: Yi Ge, Shoichiro Oda, YUICHI AKIYAMA, Takeshi Hoshida
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Patent number: 10498459Abstract: There is provided an optical transmitter including a modulator, a signal generator configured to generate in-phase or anti-phase skew adjustment signals that are identical in amplitude and frequency as signals to be input into an I axis and a Q axis of the modulator, a skew adjuster configured to perform skew adjustment upon the skew adjustment signals, a light source configured to enter light into the modulator, a monitor configured to monitor light that has been modulated using the skew adjustment signals and output from the modulator, a power detector configured to detect power of monitor light, and a controller configured to determine a skew adjustment amount with which average power of the monitor light is at a maximum or minimum value as an optimum skew adjustment value while changing a skew adjustment amount of the skew adjuster.Type: GrantFiled: June 12, 2018Date of Patent: December 3, 2019Assignee: FUJITSU LIMITEDInventors: Yoshitaka Nomura, Tomofumi Oyama, Hisao Nakashima, Yuichi Akiyama, Takeshi Hoshida
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Publication number: 20190326999Abstract: A compensating device includes at least one detector configured to detect intensity variation of the optical signal, at least one filter configured to extract a band where most of the optical phase distortion is generated from a component of the intensity variation of the optical signal, a control circuit configured to generate, based on the extraction with the at least one filter, a compensation signal exhibiting temporal intensity variation of the input optical signal, at least one compensation signal light source configured to output, based on the compensation signal of a controller, a compensation signal light exhibiting intensity variation in opposite phase to the temporal intensity variation of the input optical signal and having a different wavelength from a wavelength of the optical signal and an optical multiplexer configured to output to a transmission path a signal light formed by combining the optical signal and the compensation signal light.Type: ApplicationFiled: June 28, 2019Publication date: October 24, 2019Applicant: FUJITSU LIMITEDInventors: Tomoyuki Kato, Takeshi Hoshida