Patents by Inventor Atsushi Murasawa
Atsushi Murasawa 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: 20220399467Abstract: A light shielding structure of an optical circuit of the present invention uses a part of the structure of the light reception element itself to suppress stray light. A stepped electrode that covers an upper surface and side surface of a first semiconductor layer constituting a light absorption portion of the light reception element is formed at a height substantially equal to that of an optical waveguide in the optical circuit, and the light absorption portion of the light reception element is shielded from stray light by a wall-shaped or column-shaped wiring electrode extending substantially perpendicularly to a surface layer of the optical circuit. The light shielding structure of the present invention uses a part of the configuration of the light reception element, is formed integrally with the light reception element, and also has an aspect of the invention of the light reception element.Type: ApplicationFiled: June 15, 2020Publication date: December 15, 2022Inventors: Keiichi Morita, Atsushi Murasawa, Hiroki Kawashiri, Yusuke Nasu
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Patent number: 9036958Abstract: In an optical component, a part of a waveguide type optical device is fixed to a convex portion of a mount. The optical component includes an optical device support base, a pressure member and a pressure support base. The optical device support base is interposed between the mount and the presser member enough to be slidable in a direction parallel to surfaces of the mount and the presser member.Type: GrantFiled: March 9, 2011Date of Patent: May 19, 2015Assignees: NIPPON TELEGRAPH AND TELEPHONE CORPORATION, NTT ELECTRONICS CORPORATIONInventors: Motohaya Ishii, Naoki Ooba, Kazunori Seno, Yoshiyuki Doi, Ken Tsuzuki, Takao Fukumitsu, Atsushi Murasawa, Fumihiro Ebisawa, Hiroshi Terui, Tomoyo Shibazaki, Yuichi Kikuchi
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Patent number: 8721191Abstract: In an optical component configured to fix to a mount an optical device chip in which waveguide type optical devices having different thermal expansion coefficients are butt-jointed, deterioration in reliability due to thermal stress is suppressed. The optical component (300) comprises an optical device chip (310) including an LN waveguide (311), a first PLC waveguide (312), a second PLC waveguide (313), and a fiber alignment member (314), a mount (320), and optical fibers (330). Each of connection faces between the first PLC waveguide and the fiber alignment member is configured as an tilted structure, and each of connection faces between the LN waveguide, and the first and second PLC waveguides is configured as a right-angled structure. In the right-angled structure, the connection faces are connected by an adhesive having a lower Young's modulus than that of an adhesive used on the connection faces of the tilted structure.Type: GrantFiled: August 2, 2011Date of Patent: May 13, 2014Assignees: Nippon Telegraph and Telephone Corporation, NTT Electronics CorporationInventors: Motohaya Ishii, Takashi Yamada, Yoshiyuki Doi, Takashi Saida, Ken Tsuzuki, Takashi Goh, Hiroshi Yamazaki, Shinji Mino, Takao Fukumitsu, Atsushi Murasawa, Fumihiro Ebisawa, Hiroshi Terui, Tomoyo Shibazaki, Yuichi Kikuchi
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Patent number: 8625943Abstract: Excess optical power in a waveguide device is appropriately terminated. According to one embodiment of the present invention, the waveguide device comprises a termination structure filled with a light blocking material for terminating light from the end section of a waveguide. This termination structure can be formed by forming a groove on an optical waveguide by removing the clad and core, and filling the inside of that groove with a material attenuating the intensity of the light (light blocking material). In this manner, light that enters into the termination structure is attenuated by the light blocking material, and influence on other optical devices as a crosstalk component can be suppressed. With such termination structure, not only the influence on optical devices integrated on the same substrate, but also the influence on other optical devices directly connected to that substrate can be suppressed.Type: GrantFiled: May 26, 2009Date of Patent: January 7, 2014Assignees: Nippon Telegraph and Telephone Corporation, NTT Electronics CorporationInventors: Shunichi Soma, Takashi Goh, Yasuaki Hashizume, Masahiro Yanagisawa, Takanori Ishikawa, Mitsuru Nagano, Atsushi Murasawa, Masayuki Okuno
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Publication number: 20130136393Abstract: In an optical component configured to fix to a mount an optical device chip in which a plurality of waveguide type optical devices having different thermal expansion coefficients are butt-jointed, deterioration in reliability due to thermal stress is suppressed. The optical component (300) comprises an optical device chip (310) including an LN waveguide (311), a first PLC waveguide (312) connected to an end of the LN waveguide (311), a second PLC waveguide (313) connected to the other end of the LN waveguide (311), and a fiber alignment member (314) connected to the first PLC waveguide (312), a mount (320) on which the optical device chip (310) is mounted, and optical fibers (330) aligned to the fiber alignment member (314).Type: ApplicationFiled: August 2, 2011Publication date: May 30, 2013Applicants: NTT ELECTRONICS CORPORATION, NIPPON TELEGRAPH AND TELEPHONE CORPORATIONInventors: Motohaya Ishii, Takashi Yamada, Yoshiyuki Doi, Takashi Saida, Ken Tsuzuki, Takashi Goh, Hiroshi Yamazaki, Shinji Mino, Takao Fukumitsu, Atsushi Murasawa, Fumihiro Ebisawa, Hiroshi Terui, Tomoyo Shibazaki, Yuichi Kikuchi
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Publication number: 20130011095Abstract: In an optical component, a part of a waveguide type optical device is fixed to a convex portion of a mount. The optical component includes an optical support base, a pressure member and a pressure support base. The optical device support base is interposed between the mount and the presser member enough to be slidable in a direction parallel to surfaces of the mount and the presser member.Type: ApplicationFiled: March 9, 2011Publication date: January 10, 2013Applicants: NTT ELECTRONICS CORPORATION, NIPPON TELEGRAPH AND TELEPHONE CORPORATIONInventors: Motohaya Ishii, Naoki Ooba, Kazunori Seno, Yoshiyuki Doi, Ken Tsuzuki, Takao Fukumitsu, Atsushi Murasawa, Fumihiro Ebisawa, Hiroshi Terui, Tomoyo Shibazaki, Yuichi Kikuchi
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Publication number: 20120281942Abstract: A planar lightwave circuit according to the present invention includes at least two interferometers each of which includes a plurality of optical waveguides, and dummy patterns that are provided on both sides of each of the optical waveguides of an interferometer, having an optical waveguide density lower than the highest optical waveguide density, of the interferometers. The optical waveguide density of an interferometer A1 is higher than the optical waveguide density of the interferometer A2. Therefore, the planar lightwave circuit includes dummy patterns provided on both sides of each optical waveguide of the interferometer A1.Type: ApplicationFiled: December 15, 2010Publication date: November 8, 2012Inventors: Yoshiteru Jinnouchi, Masahiko Naito, Atsushi Murasawa
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Publication number: 20110064355Abstract: Excess optical power in a waveguide device is appropriately terminated. According to one embodiment of the present invention, the waveguide device comprises a termination structure filled with a light blocking material for terminating light from the end section of a waveguide. This termination structure can be formed by forming a groove on an optical waveguide by removing the clad and core, and filling the inside of that groove with a material attenuating the intensity of the light (light blocking material). In this manner, light that enters into the termination structure is attenuated by the light blocking material, and influence on other optical devices as a crosstalk component can be suppressed. With such termination structure, not only the influence on optical devices integrated on the same substrate, but also the influence on other optical devices directly connected to that substrate can be suppressed.Type: ApplicationFiled: May 26, 2009Publication date: March 17, 2011Applicants: NIPPON TELEGRAPH AND TELEPHONE CORPORATION, NTT ELECTRONICS CORPORATIONInventors: Shunichi Soma, Takashi Goh, Yasuaki Hashizume, Masahiro Yanagisawa, Takanori Ishikawa, Mitsuru Nagano, Atsushi Murasawa, Masayuki Okuno