Patents by Inventor Katsumi Uesaka
Katsumi Uesaka 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: 20230341593Abstract: A light device according to one embodiment includes a light source and an optical lens having an incidence plane extending in both a first axis and a second axis intersecting the first axis and an emission plane extending in both the first axis and the second axis. The optical lens converts incident light emitted from the light source and incident on the incidence plane into parallel light and emits the parallel light from the emission plane, and the incidence plane has a convex portion provided in a first direction in which the first axis extends and a concave portion provided in a second direction in which the second axis extends.Type: ApplicationFiled: April 24, 2023Publication date: October 26, 2023Inventors: Manabu SHIOZAKI, Yasutaka MIZUNO, Tomoya SAEKI, Katsumi UESAKA
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Publication number: 20220128777Abstract: Disclosed is an optical device including a first lens and a second lens. The first lens of the optical device is joined to an end surface of an optical waveguide of an optical element to emit light emitted from the optical element. The second lens is optically coupled with the first lens to convert the light emitted from the first lens into collimated light.Type: ApplicationFiled: October 21, 2021Publication date: April 28, 2022Applicant: Sumitomo Electric Industries, Ltd.Inventors: Manabu Shiozaki, Tomoya Saeki, Katsumi Uesaka
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Patent number: 11128104Abstract: A wavelength-tunable light source includes a wavelength-tunable laser including a first region and a second region each of which includes at least one of heaters, a frequency locker configured to receive output light of the wavelength-tunable laser and output two electric control signals whose phases are mutually different by 90° and having frequency period with respect to frequency of the output light, a thermal electric cooler on which the wavelength-tunable laser and the frequency locker are mounted, and a controller configured to control temperature of the heaters, and the thermal electric cooler on the basis of any one of the two electric control signals.Type: GrantFiled: July 19, 2019Date of Patent: September 21, 2021Assignee: Sumitomo Electric Industries, Ltd.Inventors: Tomoko Miura, Katsumi Uesaka
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Publication number: 20200028326Abstract: A wavelength-tunable light source includes a wavelength-tunable laser including a first region and a second region each of which includes at least one of heaters, a frequency locker configured to receive output light of the wavelength-tunable laser and output two electric control signals whose phases are mutually different by 90° and having frequency period with respect to frequency of the output light, a thermal electric cooler on which the wavelength-tunable laser and the frequency locker are mounted, and a controller configured to control temperature of the heaters, and the thermal electric cooler on the basis of any one of the two electric control signals.Type: ApplicationFiled: July 19, 2019Publication date: January 23, 2020Applicant: Sumitomo Electric Industries, Ltd.Inventors: Tomoko Miura, Katsumi Uesaka
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Patent number: 9819149Abstract: An optical transmitter that includes a wavelength tunable laser diode (LD) with a narrowed emission linewidth is disclosed. The optical transmitter further includes a feedback unit and an optical attenuator. The feedback unit, receiving a portion of laser light of the wavelength tunable LD, generates feedback light by rotating the polarization of the laser light by 90±5°, and returns thus generated feedback light in the wavelength tunable LD. The optical attenuator adjusts power of the feedback light to reduce a line wide of the laser light, or frequency noises thereof.Type: GrantFiled: November 21, 2016Date of Patent: November 14, 2017Assignees: Sumitomo Electrix Industries, Ltd., National Institute of Advanced Industrial Science and TechnologyInventors: Katsumi Uesaka, Haruhiko Kuwatsuka, Aaron Albores-Mejia
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Patent number: 9686018Abstract: An optical transmitter that narrows the linewidth of its output light is disclosed. The optical transmitter includes a wavelength tunable laser diode (LD) known as a CSG-DR LD integrated with a semiconductor optical amplifier (SOA) driven in a constant magnitude mode. The wavelength of the light output from the LD is determined by transmission through an etalon filter. The optical transmitter feeds the output of the etalon filter back to an injection current supplied to the LD to reduce phase noise inherently contained in the output light.Type: GrantFiled: March 18, 2016Date of Patent: June 20, 2017Assignee: SUMITOMO ELECTRIC INDUSTRIES, LTD.Inventor: Katsumi Uesaka
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Publication number: 20170149209Abstract: An optical transmitter that includes a wavelength tunable laser diode (LD) with a narrowed emission linewidth is disclosed. The optical transmitter further includes a feedback unit and an optical attenuator. The feedback unit, receiving a portion of laser light of the wavelength tunable LD, generates feedback light by rotating the polarization of the laser light by 90±5°, and returns thus generated feedback light in the wavelength tunable LD. The optical attenuator adjusts power of the feedback light to reduce a line wide of the laser light, or frequency noises thereof.Type: ApplicationFiled: November 21, 2016Publication date: May 25, 2017Inventors: Katsumi Uesaka, Haruhiko Kuwatsuka, Aaron Albores-Mejia
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Publication number: 20160276803Abstract: An optical transmitter that narrows the linewidth of the output light is disclosed. The optical transmitter includes a wavelength tunable laser diode (LD) type of the CSG-DR LD integrated with a semiconductor optical amplifier (SOA) driven by the constant magnitude mode. The wavelength of the light output from the LD is determined through the etalon filter. The optical transmitter feeds the output of the etalon filter back to the injection current supplied to the LID to reduce the phase noise inherently contained in the output light.Type: ApplicationFiled: March 18, 2016Publication date: September 22, 2016Applicant: SUMITOMO ELECTRIC INDUSTRIES, LTD.Inventor: Katsumi UESAKA
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Patent number: 9444221Abstract: A laser apparatus for tuning the emission wavelength of a wavelength tunable laser diode will be described. The apparatus includes a tunable LD with heaters to tune the emission wavelength of the tunable LD, and a controller to control the power supplied to the heaters. A feature of the laser apparatus is that the controller supplies pre-emphasis power to the heaters before the supplement of the power corresponding to the re-tuned emission wavelength to accelerate the stability of the temperature of the heaters.Type: GrantFiled: July 2, 2015Date of Patent: September 13, 2016Assignees: Sumitomo Electric Industries, Ltd., National Institute of Advanced Industrial Science and TechnologyInventors: Katsumi Uesaka, Eiichi Banno, Hajime Shoji, Hiroyuki Matsuura, Haruhiko Kuwatsuka, Ken Tanizawa, Shu Namiki
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Patent number: 9395504Abstract: A system includes: a splitter to branch an optical signal output by a wavelength-tunable light source into first to third optical signals; a first photodiode to perform an optical electrical conversion of the first optical signal transmitting a first etalon; a second photodiode to perform an optical electrical conversion of the second optical signal transmitting a second etalon, an FSR of the second etalon being identical to that of the first etalon, peak wavelengths of intensity of a transmitted light of the second etalon being different from those of the first etalon; a third photodiode to perform an optical electrical conversion of the third optical signal; and a controller to control the wavelength-tunable light source with use of a coefficient calculated by following formulas (1) or (2), Coefficient=(PD1?A·PD3)/(PD2?B·PD3) (1) and Coefficient=(PD2?B·PD3)/(PD1?A·PD3) (2).Type: GrantFiled: September 17, 2014Date of Patent: July 19, 2016Assignees: Sumitomo Electric Industries, Ltd., National Institute of Advanced Industrial Science and TechnologyInventors: Katsumi Uesaka, Eiichi Banno, Hajime Shoji, Hiroyuki Matsuura, Haruhiko Kuwatsuka, Ken Tanizawa, Shu Namiki
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Patent number: 9395487Abstract: Provided are an optical element and a wavelength monitor capable of detecting a wavelength with high accuracy and at high speed while suppressing a size. The optical element includes: a branch waveguide section configured to branch an input light beam and generate two outputs routed via paths having mutually different optical path lengths; and an optical synthesis section configured to synthesize the two outputs and output two optical signals having different light intensities with regards to a wavelength of the input light beam and exhibiting a mutual phase difference.Type: GrantFiled: September 23, 2014Date of Patent: July 19, 2016Assignee: Sumitomo Electric Industries, Ltd.Inventors: Katsumi Uesaka, Yutaka Onishi
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Patent number: 9274399Abstract: A Mach-Zehnder optical modulator includes a join-and-branch portion; two light wave guides connected with the join-and-branch portion; an output light waveguide connected with the join-and-branch portion; arm electrodes respectively provided on the two light waveguides; and a ground electrode that is provided at an edge of at least one of the arm electrodes along the light waveguide, is spaced from the arm electrode and is grounded.Type: GrantFiled: May 19, 2014Date of Patent: March 1, 2016Assignee: SUMITOMO ELECTRIC INDUSTRIES, LTD.Inventors: Kazuhiro Yamaji, Katsumi Uesaka
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Publication number: 20160006212Abstract: A laser apparatus for tuning the emission wavelength of a wavelength tunable laser diode will be described. The apparatus includes a tunable LD with heaters to tune the emission wavelength of the tunable LD, and a controller to control the power supplied to the heaters. A feature of the laser apparatus is that the controller supplies pre-emphasis power to the heaters before the supplement of the power corresponding to the re-tuned emission wavelength to accelerate the stability of the temperature of the heaters.Type: ApplicationFiled: July 2, 2015Publication date: January 7, 2016Inventors: Katsumi Uesaka, Eiichi Banno, Hajime Shoji, Hiroyuki Matsuura, Haruhiko Kuwatsuka, Ken Tanizawa, Shu Namiki
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Publication number: 20150085292Abstract: Provided are an optical element and a wavelength monitor capable of detecting a wavelength with high accuracy and at high speed while suppressing a size. The optical element includes: a branch waveguide section configured to branch an input light beam and generate two outputs routed via paths having mutually different optical path lengths; and an optical synthesis section configured to synthesize the two outputs and output two optical signals having different light intensities with regards to a wavelength of the input light beam and exhibiting a mutual phase difference.Type: ApplicationFiled: September 23, 2014Publication date: March 26, 2015Inventors: Katsumi UESAKA, Yutaka ONISHI
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Publication number: 20150076990Abstract: A system includes: a splitter to branch an optical signal output by a wavelength-tunable light source into first to third optical signals; a first photodiode to perform an optical electrical conversion of the first optical signal transmitting a first etalon; a second photodiode to perform an optical electrical conversion of the second optical signal transmitting a second etalon, an FSR of the second etalon being identical to that of the first etalon, peak wavelengths of intensity of a transmitted light of the second etalon being different from those of the first etalon; a third photodiode to perform an optical electrical conversion of the third optical signal; and a controller to control the wavelength-tunable light source with use of a coefficient calculated by following formulas (1) or (2), Coefficient=(PD1?A·PD3)/(PD2?B·PD3) (1) and Coefficient=(PD2?B·PD3)/(PD1?A·PD3) (2).Type: ApplicationFiled: September 17, 2014Publication date: March 19, 2015Inventors: Katsumi UESAKA, Eiichi BANNO, Hajime SHOJI, Hiroyuki MATSUURA, Haruhiko KUWATSUKA, Ken TANIZAWA, Shu NAMIKI
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Publication number: 20140254974Abstract: A Mach-Zehnder optical modulator includes a join-and-branch portion; two light wave guides connected with the join-and-branch portion; an output light waveguide connected with the join-and-branch portion; arm electrodes respectively provided on the two light waveguides; and a ground electrode that is provided at an edge of at least one of the arm electrodes along the light waveguide, is spaced from the arm electrode and is grounded.Type: ApplicationFiled: May 19, 2014Publication date: September 11, 2014Applicant: SUMITOMO ELECTRIC INDUSTRIES, LTD.Inventors: Kazuhiro Yamaji, Katsumi Uesaka
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Patent number: 8781263Abstract: A Mach-Zehnder optical modulator includes a join-and-branch portion, two light wave guides connected with the join-and-branch portion, two output light waveguides connected with the join-and-branch portion, arm electrodes respectively provided on the two light waveguides, light intensity detection electrodes respectively provided on the two output light waveguides, and a leakage suppression electrode provided between the arm electrodes and the light intensity detection electrodes.Type: GrantFiled: November 30, 2011Date of Patent: July 15, 2014Assignee: Sumitomo Electric Industries, Ltd.Inventors: Kazuhiro Yamaji, Katsumi Uesaka
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Patent number: 8660388Abstract: An optical modulation apparatus including: a Mach-Zehnder optical modulator having two optical waveguides, two output optical waveguides and a join-and-branch portion; a phase adjustment circuit configured to output a phase control signal to phase adjustment electrodes provided respectively on the two optical waveguides; a drive circuit configured to output a modulation signal to modulation electrodes provided respectively on the two optical waveguides as a differential signal, the modulation signal modulating lights propagated in the two optical waveguides; and a signal polarity reversal circuit configured to reverse a polarity of the differential signal to be output from the drive circuit.Type: GrantFiled: November 29, 2011Date of Patent: February 25, 2014Assignee: Sumitomo Electric Industries, Ltd.Inventors: Morihiro Seki, Katsumi Uesaka
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Patent number: 8620116Abstract: An optical modulation apparatus, including: a Mach-Zehnder optical modulator having two light waveguides, two output light waveguides, and a join-and-branch portion located therebetween; a drive circuit configured to output a modulation signal to modulation electrodes provided respectively on the two light waveguides as a differential signal, the modulation signal modulating lights propagated in the two light waveguides; a phase adjustment circuit configured to control first phase control signals to be output to phase adjustment electrodes provided respectively on the two light waveguides, and adjust phases of lights propagated in the two light waveguides; a phase shift control circuit configured to switch second phase control signals to be output to phase shift electrodes provided respectively on the two light waveguides, and change phases of the lights propagated in the two light waveguides; and a signal polarity reversal circuit configured to reverse a polarity of the differential signal.Type: GrantFiled: January 9, 2012Date of Patent: December 31, 2013Assignee: Sumitomo Electric Industries, Ltd.Inventors: Katsumi Uesaka, Tohru Watanabe
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Publication number: 20130136388Abstract: An optical modulation apparatus, including: a Mach-Zehnder optical modulator having two light waveguides, two output light waveguides, and a join-and-branch portion located therebetween; a drive circuit configured to output a modulation signal to modulation electrodes provided respectively on the two light waveguides as a differential signal, the modulation signal modulating lights propagated in the two light waveguides; a phase adjustment circuit configured to control first phase control signals to be output to phase adjustment electrodes provided respectively on the two light waveguides, and adjust phases of lights propagated in the two light waveguides; a phase shift control circuit configured to switch second phase control signals to be output to phase shift electrodes provided respectively on the two light waveguides, and change phases of the lights propagated in the two light waveguides; and a signal polarity reversal circuit configured to reverse a polarity of the differential signal.Type: ApplicationFiled: January 9, 2012Publication date: May 30, 2013Applicant: SUMITOMO ELECTRIC INDUSTRIES, LTD.Inventors: Katsumi Uesaka, Tohru Watanabe