Patents by Inventor Takaharu Ohyama
Takaharu Ohyama 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: 8916946Abstract: The present invention is intended to provide a compact and simple optical semiconductor device that reduces crosstalk (leakage current) between light receiving elements. According to the present invention, since a back surface electrode is a mirror-like thin film, crosstalk to an adjacent light receiving element can be suppressed, thereby reducing a detection error of a light intensity. By disposing a patterned back surface electrode or by disposing an ohmic electrode at the bottom of an insulating film over the whole back surface, contact resistance on the back surface can be reduced. By using the optical semiconductor elements with a two-dimensional arrangement and by using a mirror-like thin film as the back surface electrode, crosstalk can be reduced. By accommodating the optical semiconductor elements in the housing in a highly hermetic condition, the optical semiconductor elements can be protected from an external environment.Type: GrantFiled: March 4, 2014Date of Patent: December 23, 2014Assignees: Nippon Telegraph and Telephone Corporation, NTT Electronics CorporationInventors: Yoshiyuki Doi, Yoshifumi Muramoto, Takaharu Ohyama
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Publication number: 20140183677Abstract: The present invention is intended to provide a compact and simple optical semiconductor device that reduces crosstalk (leakage current) between light receiving elements. According to the present invention, since a back surface electrode is a mirror-like thin film, crosstalk to an adjacent light receiving element can be suppressed, thereby reducing a detection error of a light intensity. By disposing a patterned back surface electrode or by disposing an ohmic electrode at the bottom of an insulating film over the whole back surface, contact resistance on the back surface can be reduced. By using the optical semiconductor elements with a two-dimensional arrangement and by using a mirror-like thin film as the back surface electrode, crosstalk can be reduced. By accommodating the optical semiconductor elements in the housing in a highly hermetic condition, the optical semiconductor elements can be protected from an external environment.Type: ApplicationFiled: March 4, 2014Publication date: July 3, 2014Applicants: NTT Electronics Corporation, Nippon Telegraph and Telephone CorporationInventors: Yoshiyuki Doi, Yoshifumi Muramoto, Takaharu Ohyama
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Patent number: 8704322Abstract: The present invention is intended to provide a compact and simple optical semiconductor device that reduces crosstalk (leakage current) between light receiving elements. According to the present invention, since a back surface electrode is a mirror-like thin film, crosstalk to an adjacent light receiving element can be suppressed, thereby reducing a detection error of a light intensity. By disposing a patterned back surface electrode or by disposing an ohmic electrode at the bottom of an insulating film over the whole back surface, contact resistance on the back surface can be reduced. By using the optical semiconductor elements with a two-dimensional arrangement and by using a mirror-like thin film as the back surface electrode, crosstalk can be reduced. By accommodating the optical semiconductor elements in the housing in a highly hermetic condition, the optical semiconductor elements can be protected from an external environment.Type: GrantFiled: January 23, 2012Date of Patent: April 22, 2014Assignees: Nippon Telegraph and Telephone Corporation, NTT Electronics CorporationInventors: Yoshiyuki Doi, Yoshifumi Muramoto, Takaharu Ohyama
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Patent number: 8545111Abstract: An optical module has a structure for reducing the stress applied to a package. The optical module is structured so that an end face of a waveguide (37) of a planar lightwave circuit (30) is joined to a plurality of packages (40) storing therein optical elements so that the waveguide is optically coupled to the optical elements. The optical module includes a housing (3) storing therein a planar lightwave circuit and a plurality of packages in which an upper face of a protrusion (270) formed in the bottom section is fixed to the planar lightwave circuit (30). Each of the plurality of packages (40) is electrically connected to an electric part (22) provided in the housing (3) via flexible printed circuits (271a, 271b).Type: GrantFiled: June 30, 2008Date of Patent: October 1, 2013Assignees: Nippon Telegraph and Telephone Corporation, NTT Electronics CorporationInventors: Takaharu Ohyama, Yoshiyuki Doi, Ikuo Ogawa, Akimasa Kaneko, Yasuaki Tamura, Yuichi Suzuki
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Publication number: 20120193740Abstract: The present invention is intended to provide a compact and simple optical semiconductor device that reduces crosstalk (leakage current) between light receiving elements. According to the present invention, since a back surface electrode is a mirror-like thin film, crosstalk to an adjacent light receiving element can be suppressed, thereby reducing a detection error of a light intensity. By disposing a patterned back surface electrode or by disposing an ohmic electrode at the bottom of an insulating film over the whole back surface, contact resistance on the back surface can be reduced. By using the optical semiconductor elements with a two-dimensional arrangement and by using a mirror-like thin film as the back surface electrode, crosstalk can be reduced. By accommodating the optical semiconductor elements in the housing in a highly hermetic condition, the optical semiconductor elements can be protected from an external environment.Type: ApplicationFiled: January 23, 2012Publication date: August 2, 2012Applicants: NTT ELECTRONICS CORPORATION, NIPPON TELEGRAPH AND TELEPHONE CORPORATIONInventors: Yoshiyuki Doi, Yoshifumi Muramoto, Takaharu Ohyama
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Publication number: 20100322569Abstract: An optical module has a structure for reducing the stress applied to a package. The optical module is structured so that an end face of a waveguide (37) of a planar lightwave circuit (30) is joined to a plurality of packages (40) storing therein optical elements so that the waveguide is optically coupled to the optical elements. The optical module includes a housing (3) storing therein a planar lightwave circuit and a plurality of packages in which an upper face of a protrusion (270) formed in the bottom section is fixed to the planar lightwave circuit (30). Each of the plurality of packages (40) is electrically connected to an electric part (22) provided in the housing (3) via flexible printed circuits (271a, 271b).Type: ApplicationFiled: June 30, 2008Publication date: December 23, 2010Applicants: NIPPON TELEGRAPH AND TELEPHONE CORPORATION, NTT ELECTRONICS CORPORATIONInventors: Takaharu Ohyama, Yoshiyuki Doi, Ikuo Ogawa, Akimasa Kaneko, Yasuaki Tamura, Yuichi Suzuki
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Publication number: 20080226290Abstract: By reducing the number of PD arrays, and by simplifying the configuration of an optical power monitor in a WDM system, a miniaturized, cost reduced optical signal monitoring apparatus, optical system or optical signal monitoring method is provided. An optical power monitor 1 has an optical switch 30 having four input ports 31, a DMUX 2 having 48 output ports, and six CSP type PD array modules 50 each including an 8-channel PD array. The output port 32 of the optical switch 30 having four switchable input ports 31 is optically connected to the input port 21 of the AWG 20. The 48 output ports 22 of the AWG 20 are each optically connected to photosensitive surfaces 53 of the individual PDs included in the CSP type PD array modules 50. The CSP type PD array modules 50 are mounted on the end face of the AWG 20.Type: ApplicationFiled: March 5, 2008Publication date: September 18, 2008Applicants: Nippon Telegraph and Telephone Corporation, NTT Electronics CorporationInventors: Takaharu Ohyama, Takashi Goh, Shin Kamei, Shunichi Sohma, Mikitaka Itoh, Ikuo Ogawa, Akimasa Kaneko, Tomoyuki Yamada, Mitsuru Nagano, Yoshiyuki Doi, Takashi Saida
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Patent number: 7397977Abstract: A wave transmission medium includes an input port 3-1 and an output port 3-2. A field distribution 1 and a field distribution 2 are obtained by numerical calculations. The field distribution 1 is a field distribution of the propagation light (forward propagation light) launched into the input port 3-1. The field distribution 2 is a field distribution of the phase conjugate light (reverse propagation light) resulting from reversely transmitting from the output port side an output field that is expected to be output from the output port 3-2 when an optical signal is launched into the input port 3-1. According to the field distributions 1 and 2, a spatial refractive index distribution is calculated such that the phase difference between the propagation light and reverse propagation light is eliminated at individual points (x, z) in the medium.Type: GrantFiled: December 25, 2003Date of Patent: July 8, 2008Assignee: Nippon Telegraph and Telephone CorporationInventors: Toshikazu Hashimoto, Ikuo Ogawa, Takeshi Kitagawa, Senichi Suzuki, Masahiro Yanagisawa, Tomohiro Shibata, Masaki Koutoku, Hiroshi Takahashi, Ryou Nagase, Masaru Kobayashi, Shuichiro Asakawa, Yoshiteru Abe, Tsutomu Kitoh, Takaharu Ohyama
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Publication number: 20060126992Abstract: A wave transmission medium includes an input port 3-1 and an output port 3-2. A field distribution 1 and a field distribution 2 are obtained by numerical calculations. The field distribution 1 is a field distribution of the propagation light (forward propagation light) launched into the input port 3-1. The field distribution 2 is a field distribution of the phase conjugate light (reverse propagation light) resulting from reversely transmitting from the output port side an output field that is expected to be output from the output port 3-2 when an optical signal is launched into the input port 3-1. According to the field distributions 1 and 2, a spatial refractive index distribution is calculated such that the phase difference between the propagation light and reverse propagation light is eliminated at individual points (x, z) in the medium.Type: ApplicationFiled: December 25, 2003Publication date: June 15, 2006Inventors: Toshikazu Hashimoto, Ikuo Ogawa, Takeshi Kitagawa, Senichi Suzuki, Masahiro Yanagisawa, Tomohiro Shibata, Masaki Koutoku, Hiroshi Takahashi, Ryou Nagase, Masaru Kobayashi, Shuichiro Asakawa, Yoshiteru Abe, Tsutomu Kitoh, Takaharu Ohyama