Patents by Inventor Shin Kamei
Shin Kamei 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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Patent number: 10908356Abstract: An optical circuit board which is mounted with a loop-back circuit for returning aligning light to the fiber array in the vicinity of the fiber array connection end. Since an aligning loop-back circuit can be formed in an optical waveguide pattern, a production cost does not increase in comparison to an optical circuit board of the related art. The aligning light combined from the optical fiber to the aligning port of the optical circuit board is returned to the optical fiber around the loop-back circuit. Therefore, it is possible to perform alignment using the returned light. That is, alignment can be performed while being mounted on a package without installing a light-reflecting film or mirror.Type: GrantFiled: November 2, 2017Date of Patent: February 2, 2021Assignees: NTT ELECTRONICS CORPORATION, NIPPON TELEGRAPH AND TELEPHONE CORPORATIONInventors: Tomohiro Nakanishi, Motoki Minami, Satoru Konno, Yuichi Suzuki, Teruaki Sato, Shigeo Nagashima, Shinji Mino, Motohaya Ishii, Shunichi Soma, Shin Kamei, Shuichiro Asakawa
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Patent number: 10720543Abstract: A germanium photodetector which reduces a dark current without degradation of a photocurrent includes: a silicon substrate; a lower clad layer formed on the silicon substrate; a core layer formed on the lower clad layer; a p-type silicon slab formed in a part of the core layer and doped with a p-type impurity ion; p++ silicon electrode sections that are highly-doped with a p-type impurity and act as an electrode; and germanium layers which absorb light. The germanium photodetector further includes an upper clad layer, an n-type germanium region doped with an n-type impurity above the germanium layer, and an electrode. According to the present invention, two germanium layers are provided on the p-type silicon slab so as to miniaturize the area of the surface of the individual germanium layer in contact with the p-type silicon slab, so that the dark current due to threading dislocation can be reduced.Type: GrantFiled: August 28, 2016Date of Patent: July 21, 2020Assignee: NIPPON TELEGRAPH AND TELEPHONE CORPORATIONInventors: Hiroshi Fukuda, Shin Kamei, Ken Tsuzuki, Makoto Jizodo, Kiyofumi Kikuchi
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Patent number: 10649147Abstract: An optical module that is connectable to an optical fiber array and that can be packaged in a high density. Two package modules are mounted on a board, and optical waveguides in a Si photonic lightwave circuit mounted on the package module are connected to an optical fiber array fixed to an optical fiber block. Moreover, output end surfaces of the optical waveguides in the Si photonic lightwave circuit are perpendicular to a mount surface of the package module. The optical waveguides in the Si photonic lightwave circuit may be tilted at an appropriate angle with respect to a direction perpendicular to a right end surface. Moreover, the optical fiber block fixes optical fibers with the optical fibers tilted with respect to a direction perpendicular to an end surface connected to the Si photonic lightwave circuit.Type: GrantFiled: May 12, 2017Date of Patent: May 12, 2020Assignees: NTT ELECTRONICS CORPORATION, NIPPON TELEGRAPH AND TELEPHONE CORPORATIONInventors: Tomohiro Nakanishi, Teruaki Sato, Motohaya Ishii, Satoru Konno, Yuichi Suzuki, Shigeo Nagashima, Shinji Mino, Shuichiro Asakawa, Hiroshi Fukuda, Shin Kamei, Shunichi Soma, Ken Tsuzuki, Mitsuo Usui, Takashi Saida
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Patent number: 10601522Abstract: An optical receiver is configured so as to be as less susceptible to noise as possible even in the case where high noise occurs inside an optical transceiver. The optical receiver includes a connection part that connects two photodiodes (PDs) constituting a dual photodiode and a transimpedance amplifier (TIA), wherein signal lines from the dual photodiode are surrounded by a conductor pattern that is not connected to each of the signal lines for each channel, and the conductor pattern is connected to a ground pattern on the transimpedance amplifier or a power source pattern for the PDs.Type: GrantFiled: June 19, 2017Date of Patent: March 24, 2020Assignee: NIPPON TELEGRAPH AND TELEPHONE CORPORATIONInventors: Toshihiro Itoh, Yuriko Kawamura, Kiyofumi Kikuchi, Ken Tsuzuki, Hiroshi Fukuda, Shin Kamei
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Publication number: 20190353844Abstract: An optical module which is connectable to an optical fiber array and which can be packaged in a high density. Two 30 mm square package modules are mounted on a board, and optical waveguides in a 20 mm square Si photonic lightwave circuit mounted on the package module are connected to an optical fiber array fixed to an optical fiber block (15×10 mm). Moreover, output end surfaces of the optical waveguides in the Si photonic lightwave circuit are perpendicular to a mount surface of the package module. In the embodiment, the optical waveguides in the Si photonic lightwave circuit are tilted at an appropriate angle, for example, 20 degrees with respect to a direction perpendicular to a right end surface. Moreover, the optical fiber block fixes optical fibers with the optical fibers tilted at 20 degrees with respect to a direction perpendicular to an end surface connected to the Si photonic lightwave circuit.Type: ApplicationFiled: May 12, 2017Publication date: November 21, 2019Inventors: Tomohiro Nakanishi, Teruaki Sato, Motohaya Ishii, Satoru Konno, Yuichi Suzuki, Shigeo Nagashima, Shinji Mino, Shuichiro Asakawa, Hiroshi Fukuda, Shin Kamei, Shunichi Soma, Ken Tsuzuki, Mitsuo Usui, Takashi Saida
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Publication number: 20190181961Abstract: An optical receiver is configured so as to be as less susceptible to noise as possible even in the case where high noise occurs inside an optical transceiver. The optical receiver includes a connection part that connects two photodiodes (PDs) constituting a dual photodiode and a transimpedance amplifier (TIA), wherein signal lines from the dual photodiode are surrounded by a conductor pattern that is not connected to each of the signal lines for each channel, and the conductor pattern is connected to a ground pattern on the transimpedance amplifier or a power source pattern for the PDs.Type: ApplicationFiled: June 19, 2017Publication date: June 13, 2019Inventors: Toshihiro Itoh, Yuriko Kawamura, Kiyofumi Kikuchi, Ken Tsuzuki, Hiroshi Fukuda, Shin Kamei
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Patent number: 10295744Abstract: A coherent optical mixer circuit is provided that can measure a phase error without requiring a step of cutting away a delay circuit. Odd-numbered or even-numbered two of four inputs of an 4-input-and-4-output multimode interference circuit are connected to an input mechanism. The four outputs of the multimode interference circuit are all connected to an output mechanism to the exterior. Other two inputs of the multimode interference circuit are connected to two monitor waveguides. One of the monitor waveguide is longer than the other to configure a light delay circuit. The monitor waveguides constituting the light delay circuit are connected to the respective outputs of a 2-branched light splitter. The 2-branched light splitter has an input connected to a monitor light input mechanism from the exterior via a monitor input waveguide.Type: GrantFiled: May 27, 2016Date of Patent: May 21, 2019Assignee: Nippon Telegraph and Telephone CorporationInventors: Shin Kamei, Makoto Jizodo, Hiroshi Fukuda, Kiyofumi Kikuchi, Ken Tsuzuki
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Patent number: 10277271Abstract: An optical module that suppresses crosstalk between high-frequency transmission lines includes at least one set of: an optical port; an optical processing circuit optically connected to the optical port; an electro-optical transducer optically connected to the optical processing circuit; two or more high-frequency transmission lines connected to the electro-optical transducer; and electrical ports connected to the high-frequency transmission lines, and includes a conductive cover block which is provided above the high-frequency transmission lines so as to at least partly cover the high-frequency transmission lines and which is grounded.Type: GrantFiled: July 27, 2016Date of Patent: April 30, 2019Assignee: NIPPON TELEGRAPH AND TELEPHONE CORPORATIONInventors: Kiyofumi Kikuchi, Hiroshi Fukuda, Takashi Saida, Shin Kamei, Ken Tsuzuki
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Patent number: 10243664Abstract: An optical modulator driver circuit (1) includes an amplifier (50, Q10, Q11, R10-R13), and a current amount adjustment circuit (51) capable of adjusting a current amount of the amplifier (50) in accordance with a desired operation mode. The current amount adjustment circuit (51) includes at least two current sources (IS10) that are individually ON/OFF-controllable in accordance with a binary control signal representing the desired operation mode.Type: GrantFiled: May 9, 2014Date of Patent: March 26, 2019Assignee: NIPPON TELEGRAPH AND TELEPHONE CORPORATIONInventors: Munehiko Nagatani, Hideyuki Nosaka, Toshihiro Itoh, Koichi Murata, Hiroyuki Fukuyama, Takashi Saida, Shin Kamei, Hiroshi Yamazaki, Nobuhiro Kikuchi, Hiroshi Koizumi, Masafumi Nogawa, Hiroaki Katsurai, Hiroyuki Uzawa, Tomoyoshi Kataoka, Naoki Fujiwara, Hiroto Kawakami, Kengo Horikoshi, Yves Bouvier, Mikio Yoneyama, Shigeki Aisawa, Masahiro Suzuki
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Patent number: 10190941Abstract: The visual detection of a silicon optical circuit in a conventional technique depends on sensory decision by a human who visually conducts checking, and there has been limitation in completely detecting small flaws. The optical circuit of the present invention includes, in addition to an optical circuit that implements desired functions, an optical waveguide for flaw detection which surrounds the entire optical circuit and which is sufficiently proximate to the optical waveguide of the optical circuit and grating couplers connected to the optical waveguide for detection. Based on the transmission characteristic measurement of the optical waveguide for detection using the grating couplers, a flaw within each chip can be efficiently discovered in the state of a wafer before being cut into chips. A flaw can also be discovered hierarchically by providing individual optical waveguides for detection for respective chips and by further forming one common optical waveguide for detection over the plurality of chips.Type: GrantFiled: November 17, 2016Date of Patent: January 29, 2019Assignee: NIPPON TELEGRAPH AND TELEPHONE CORPORATIONInventors: Shin Kamei, Makoto Jizodo, Kotaro Takeda, Hiroshi Fukuda
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Patent number: 10193653Abstract: A one chip-integrated digital coherent polarization multiplexing optical transmission and reception circuit with optimal optical power distribution between sending and receiving is provided by using an optical power splitter having a branching ratio of a lower asymmetry property so that the unbalanced loss depending on the polarization path can be compensated. A polarization multiplexing optical transmission and reception circuit includes a polarization multiplexing optical transmission circuit, including: the first optical power splitter for branching the optical power of continuous light outputted from a light source; one polarization optical modulation circuit at the side of a path having a higher loss connected to one output of the first optical power splitter; the second optical power splitter connected to the other output of the first optical power splitter; and the other polarization optical modulation circuit connected to one output of the second optical power splitter.Type: GrantFiled: April 12, 2016Date of Patent: January 29, 2019Assignee: Nippon Telegraph and Telephone CorporationInventors: Shin Kamei, Makoto Jizodo, Hiroshi Fukuda, Kiyofumi Kikuchi, Ken Tsuzuki
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Patent number: 10165690Abstract: In a conventional soldering method, an FPC-side electrode pad and a package-side electrode pad are closely joined together with a solder layer, and the soldered state after a joining process has not been easily confirmed visually. The present invention provides a solder joint structure including a side face electrode which is formed on each of the side faces of the end parts of an FPC board and a package or PCB board that are to be soldered, extending vertically relative to the faces constituting each of electrode pads on the boards, and which introduces solder. On the side face electrodes of the board end parts, a part of solder that is formed continuously from the solder joint portion is visible and the state of the solder joint between the electrode pads on the two boards can be confirmed. The efficiency of solder joint tests can be improved.Type: GrantFiled: June 17, 2016Date of Patent: December 25, 2018Assignee: NIPPON TELEGRAPH AND TELEPHONE CORPORATIONInventors: Mitsuo Usui, Kiyofumi Kikuchi, Ken Tsuzuki, Hiroshi Fukuda, Shuichiro Asakawa, Shin Kamei, Shunichi Soma, Takashi Saida
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Patent number: 10146099Abstract: The present invention provides an optical modulator including a substrate and a phase modulation portion on the substrate. The phase modulation portion includes an optical waveguide comprised of a first clad layer, a semiconductor layer that is laminated on the first clad layer and has a refraction index higher than the first clad layer and a second clad layer that is laminated on the semiconductor layer and has a refraction index lower than the semiconductor layer, a first traveling wave electrode, and a second traveling wave electrode.Type: GrantFiled: December 8, 2015Date of Patent: December 4, 2018Assignee: NIPPON TELEGRAPH AND TELEPHONE CORPORATIONInventors: Ken Tsuzuki, Shin Kamei, Makoto Jizodo
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Publication number: 20180335365Abstract: The visual detection of a silicon optical circuit in a conventional technique depends on sensory decision by a human who visually conducts checking, and there has been limitation in completely detecting small flaws. The optical circuit of the present invention includes, in addition to an optical circuit that implements desired functions, an optical waveguide for flaw detection which surrounds the entire optical circuit and which is sufficiently proximate to the optical waveguide of the optical circuit and grating couplers connected to the optical waveguide for detection. Based on the transmission characteristic measurement of the optical waveguide for detection using the grating couplers, a flaw within each chip can be efficiently discovered in the state of a wafer before being cut into chips. A flaw can also be discovered hierarchically by providing individual optical waveguides for detection for respective chips and by further forming one common optical waveguide for detection over the plurality of chips.Type: ApplicationFiled: November 17, 2016Publication date: November 22, 2018Inventors: Shin Kamei, Makoto Jizodo, Kotaro Takeda, Hiroshi Fukuda
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Publication number: 20180233618Abstract: A germanium photodetector which reduces a dark current without degradation of a photocurrent includes: a silicon substrate; a lower clad layer formed on the silicon substrate; a core layer formed on the lower clad layer; a p-type silicon slab formed in a part of the core layer and doped with a p-type impurity ion; p++ silicon electrode sections that are highly-doped with a p-type impurity and act as an electrode; and germanium layers which absorb light. The germanium photodetector further includes an upper clad layer, an n-type germanium region doped with an n-type impurity above the germanium layer, and an electrode. According to the present invention, two germanium layers are provided on the p-type silicon slab so as to miniaturize the area of the surface of the individual germanium layer in contact with the p-type silicon slab, so that the dark current due to threading dislocation can be reduced.Type: ApplicationFiled: August 28, 2016Publication date: August 16, 2018Inventors: Hiroshi Fukuda, Shin Kamei, Ken Tsuzuki, Makoto Jizodo, Kiyofumi Kikuchi
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Publication number: 20180198483Abstract: An optical module that suppresses crosstalk between high-frequency transmission lines includes at least one set of: an optical port; an optical processing circuit optically connected to the optical port; an electro-optical transducer optically connected to the optical processing circuit; two or more high-frequency transmission lines connected to the electro-optical transducer; and electrical ports connected to the high-frequency transmission lines, and includes a conductive cover block which is provided above the high-frequency transmission lines so as to at least partly cover the high-frequency transmission lines and which is grounded.Type: ApplicationFiled: July 27, 2016Publication date: July 12, 2018Inventors: Kiyofumi Kikuchi, Hiroshi Fukuda, Takashi Saida, Shin Kamei, Ken Tsuzuki
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Publication number: 20180199445Abstract: In a conventional soldering method, an FPC-side electrode pad and a package-side electrode pad are closely joined together with a solder layer, and the soldered state after a joining process has not been easily confirmed visually. The present invention provides a solder joint structure including a side face electrode which is formed on each of the side faces of the end parts of an FPC board and a package or PCB board that are to be soldered, extending vertically relative to the faces constituting each of electrode pads on the boards, and which introduces solder. On the side face electrodes of the board end parts, a part of solder that is formed continuously from the solder joint portion is visible and the state of the solder joint between the electrode pads on the two boards can be confirmed. The efficiency of solder joint tests can be improved.Type: ApplicationFiled: June 17, 2016Publication date: July 12, 2018Inventors: Mitsuo Usui, Kiyofumi Kikuchi, Ken Tsuzuki, Hiroshi Fukuda, Shuichiro Asakawa, Shin Kamei, Shunichi Soma, Takashi Saida
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Publication number: 20180143376Abstract: A coherent optical mixer circuit is provided that can measure a phase error without requiring a step of cutting away a delay circuit. Odd-numbered or even-numbered two of four inputs of an 4-input-and-4-output multimode interference circuit are connected to an input mechanism. The four outputs of the multimode interference circuit are all connected to an output mechanism to the exterior. Other two inputs of the multimode interference circuit are connected to two monitor waveguides. One of the monitor waveguide is longer than the other to configure a light delay circuit. The monitor waveguides constituting the light delay circuit are connected to the respective outputs of a 2-branched light splitter. The 2-branched light splitter has an input connected to a monitor light input mechanism from the exterior via a monitor input waveguide.Type: ApplicationFiled: May 27, 2016Publication date: May 24, 2018Inventors: Shin Kamei, Makoto Jizodo, Hiroshi Fukuda, Kiyofumi Kikuchi, Ken Tsuzuki
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Publication number: 20180139007Abstract: A one chip-integrated digital coherent polarization multiplexing optical transmission and reception circuit with optimal optical power distribution between sending and receiving is provided by using an optical power splitter having a branching ratio of a lower asymmetry property so that the unbalanced loss depending on the polarization path can be compensated. A polarization multiplexing optical transmission and reception circuit includes a polarization multiplexing optical transmission circuit, including: the first optical power splitter for branching the optical power of continuous light outputted from a light source; one polarization optical modulation circuit at the side of a path having a higher loss connected to one output of the first optical power splitter; the second optical power splitter connected to the other output of the first optical power splitter; and the other polarization optical modulation circuit connected to one output of the second optical power splitter.Type: ApplicationFiled: April 12, 2016Publication date: May 17, 2018Applicant: Nippon Telegraph and Telephone CorporationInventors: Shin Kamei, Makoto Jizodo, Hiroshi Fukuda, Kiyofumi Kikuchi, Ken Tsuzuki
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Publication number: 20170336696Abstract: The present invention provides an optical modulator including a substrate and a phase modulation portion on the substrate. The phase modulation portion includes an optical waveguide comprised of a first clad layer, a semiconductor layer that is laminated on the first clad layer and has a refraction index higher than the first clad layer and a second clad layer that is laminated on the semiconductor layer and has a refraction index lower than the semiconductor layer, a first traveling wave electrode, and a second traveling wave electrode.Type: ApplicationFiled: December 8, 2015Publication date: November 23, 2017Inventors: Ken Tsuzuki, Shin Kamei, Makoto Jizodo