Patents by Inventor Sunao Kurimura
Sunao Kurimura 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: 9140958Abstract: According to one embodiment, an optical element is provided with a paraelectric crystal, first and second pressers between which the paraelectric crystal is sandwiched, and fasteners. The paraelectric crystal has a periodic structure in which polarities are periodically inverted along a polarity period direction. The fasteners fix the first and second pressers to each other so that a predetermined pressure is applied in a direction intersecting with the polarity period direction, to the paraelectric crystal through the first and second pressers.Type: GrantFiled: September 26, 2012Date of Patent: September 22, 2015Assignees: NIKON CORPORATION, NATIONAL INSTITUTE FOR MATERIALS SCIENCEInventors: Masaki Harada, Kenichi Muramatsu, Sunao Kurimura
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Patent number: 8669121Abstract: A method for forming a ferroelectric spontaneous polarization reversal in a desired region of a ferroelectric substrate includes the steps of forming, for the desired region of the surface of the ferroelectric substrate, an electrode pattern or a mask pattern composed of aggregates of micropatterns, and then applying a given voltage into the desired region. The configuration of the micropatterns can be a stripe-shaped pattern, an ellipse-shaped pattern, a hexagon-shaped pattern, a network pattern, or a double cross shaped pattern. The method can further include the steps of generating many nucleuses by using the electrode pattern or the mask pattern composed of the aggregates of micropatterns, forming another electrode pattern or another mask pattern corresponding to the desired region, and then applying a given voltage into the desired region to generate a ferroelectric spontaneous polarization reversal around the nucleuses.Type: GrantFiled: April 22, 2011Date of Patent: March 11, 2014Assignees: Sumitomo Osaka Cement Co., Ltd., National Institute for Materials ScienceInventors: Futoshi Yamamoto, Junichiro Ichikawa, Satoshi Oikawa, Sunao Kurimura, Kenji Kitamura
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Patent number: 8524509Abstract: A method for forming a ferroelectric spontaneous polarization reversal, including the steps of forming a concave portion on a top face of a ferroelectric substrate or a bottom face of a ferroelectric substrate, and applying an electric field into the substrate, wherein a ferroelectric spontaneous polarization reversal is formed at least in one portion of a region of the substrate with the concave portion, and wherein the shape of the concave portion is configured such that the width of the concave portion gets narrower gradually toward the inside of the substrate. The method may further include the steps of, after the reversal, making into almost a flat-plane the top or bottom face having the concave portion, and then, forming a new concave portion in another region and applying an electric field to form another reversal in one portion of the region of the substrate having the new concave portion.Type: GrantFiled: April 22, 2011Date of Patent: September 3, 2013Assignees: Sumitomo Osaka Cement Co., Ltd., National Institute for Materials ScienceInventors: Futoshi Yamamoto, Junichiro Ichikawa, Satoshi Oikawa, Sunao Kurimura, Kenji Kitamura
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Patent number: 8422120Abstract: A wavelength conversion element is provided as one including a monocrystalline nonlinear optical crystal. The nonlinear optical crystal has: a plurality of first regions having a polarity direction along a predetermined direction; a plurality of second regions having a polarity direction opposite to the predetermined direction; an entrance face into which a fundamental incident wave having a wavelength ? and a frequency ? is incident in a direction substantially perpendicular to the predetermined direction; and an exit face from which a second harmonic with a frequency 2? generated in the crystal emerges. The plurality of first and second regions are formed as alternately arranged in a period substantially equal to d expressed by a predetermined expression, between the entrance face and the exit face.Type: GrantFiled: August 10, 2012Date of Patent: April 16, 2013Assignees: Nikon Corporation, National Institute for Materials ScienceInventors: Kenichi Muramatsu, Sunao Kurimura
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Publication number: 20120307350Abstract: A wavelength conversion element is provided as one including a monocrystalline nonlinear optical crystal. The nonlinear optical crystal has: a plurality of first regions having a polarity direction along a predetermined direction; a plurality of second regions having a polarity direction opposite to the predetermined direction; an entrance face into which a fundamental incident wave having a wavelength ? and a frequency ? is incident in a direction substantially perpendicular to the predetermined direction; and an exit face from which a second harmonic with a frequency 2? generated in the crystal emerges. The plurality of first and second regions are formed as alternately arranged in a period substantially equal to d expressed by a predetermined expression, between the entrance face and the exit face.Type: ApplicationFiled: August 10, 2012Publication date: December 6, 2012Applicants: NATIONAL INSTITUTE FOR MATERIALS SCIENCE, NIKON CORPORATIONInventors: Kenichi MURAMATSU, Sunao Kurimura
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Patent number: 8293543Abstract: A method for forming a ferroelectric spontaneous polarization reversal includes the steps of forming a convexo-concave structure on a top face of a ferroelectric substrate firstly, and then forming a ferroelectric spontaneous polarization region on the substrate including one portion of a convex portion, with a concave portion being formed on the bottom face of the substrate within a region where a ferroelectric spontaneous polarization reversal is to be formed and the convex portion is formed, and then applying an electric field into the substrate. The depth of the concave portion on the bottom face of the substrate may be greater than the height of the convex portion on the top face of the substrate. The width of the concave portion on the bottom face of the substrate may be wider than width of said convex portion on the top face of the substrate.Type: GrantFiled: April 22, 2011Date of Patent: October 23, 2012Assignees: Sumitomo Osaka Cement Co., Ltd., National Institute for Materials ScienceInventors: Futoshi Yamamoto, Junichiro Ichikawa, Satoshi Oikawa, Sunao Kurimura, Kenji Kitamura
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Patent number: 8264766Abstract: A wavelength conversion element is provided as one including a monocrystalline nonlinear optical crystal. The nonlinear optical crystal has: a plurality of first regions having a polarity direction along a predetermined direction; a plurality of second regions having a polarity direction opposite to the predetermined direction; an entrance face into which a fundamental incident wave having a wavelength ? and a frequency ? is incident in a direction substantially perpendicular to the predetermined direction; and an exit face from which a second harmonic with a frequency 2? generated in the crystal emerges. The plurality of first and second regions are formed as alternately arranged in a period substantially equal to d expressed by a predetermined expression, between the entrance face and the exit face.Type: GrantFiled: October 16, 2009Date of Patent: September 11, 2012Assignees: Nikon Corporation, National Institute for Materials ScienceInventors: Kenichi Muramatsu, Sunao Kurimura
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Patent number: 8193004Abstract: A method for forming a ferroelectric spontaneous polarization reversal in a desired region of a ferroelectric substrate, wherein thickness of the ferroelectric substrate in the desired region A of the ferroelectric substrate is thinner than in a region B outside the desired region of the substrate, comprising the step of applying a given voltage into the ferroelectric substrate by a liquid electrode method to thereby form a ferroelectric spontaneous polarization reversal in the desired region of the ferroelectric substrate.Type: GrantFiled: March 18, 2005Date of Patent: June 5, 2012Assignees: Sumitomo Osaka Cement Co., Ltd., National Institute For Materials ScienceInventors: Futoshi Yamamoto, Junichiro Ichikawa, Satoshi Oikawa, Sunao Kurimura, Kenji Kitamura
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Publication number: 20110206860Abstract: A method for forming a ferroelectric spontaneous polarization reversal includes the steps of forming a convexo-concave structure on a top face of a ferroelectric substrate firstly, and then forming a ferroelectric spontaneous polarization region on the substrate including one portion of a convex portion, with a concave portion being formed on the bottom face of the substrate within a region where a ferroelectric spontaneous polarization reversal is to be formed and the convex portion is formed, and then applying an electric field into the substrate. The depth of the concave portion on the bottom face of the substrate may be greater than the height of the convex portion on the top face of the substrate. The width of the concave portion on the bottom face of the substrate may be wider than width of said convex portion on the top face of the substrate.Type: ApplicationFiled: April 22, 2011Publication date: August 25, 2011Applicants: Sumitomo Osaka Cement Co., Ltd., National Institute for Materials ScienceInventors: Futoshi Yamamoto, Junichiro Ichikawa, Satoshi Oikawa, Sunao Kurimura, Kenji Kitamura
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Publication number: 20110197432Abstract: A method for forming a ferroelectric spontaneous polarization reversal in a desired region of a ferroelectric substrate includes the steps of forming, for the desired region of the surface of the ferroelectric substrate, an electrode pattern or a mask pattern composed of aggregates of micropatterns, and then applying a given voltage into the desired region. The configuration of the micropatterns can be a stripe-shaped pattern, an ellipse-shaped pattern, a hexagon-shaped pattern, a network pattern, or a double cross shaped pattern. The method can further include the steps of generating many nucleuses by using the electrode pattern or the mask pattern composed of the aggregates of micropatterns, forming another electrode pattern or another mask pattern corresponding to the desired region, and then applying a given voltage into the desired region to generate a ferroelectric spontaneous polarization reversal around the nucleuses.Type: ApplicationFiled: April 22, 2011Publication date: August 18, 2011Applicants: Sumitomo Osaka Cement Co., Ltd., National Institute for Materials ScienceInventors: Futoshi Yamamoto, Junichiro Ichikawa, Satoshi Oikawa, Sunao Kurimura, Kenji Kitamura
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Publication number: 20110201133Abstract: A method for forming a ferroelectric spontaneous polarization reversal, including the steps of forming a concave portion on a top face of a ferroelectric substrate or a bottom face of a ferroelectric substrate, and applying an electric field into the substrate, wherein a ferroelectric spontaneous polarization reversal is formed at least in one portion of a region of the substrate with the concave portion, and wherein the shape of the concave portion is configured such that the width of the concave portion gets narrower gradually toward the inside of the substrate. The method may further include the steps of, after the reversal, making into almost a flat-plane the top or bottom face having the concave portion, and then, forming a new concave portion in another region and applying an electric field to form another reversal in one portion of the region of the substrate having the new concave portion.Type: ApplicationFiled: April 22, 2011Publication date: August 18, 2011Applicants: Sumitomo Osaka Cement Co., Ltd., National Institute for Materials ScienceInventors: Futoshi Yamamoto, Junichiro Ichikawa, Satoshi Oikawa, Sunao Kurimura, Kenji Kitamura
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Patent number: 7985294Abstract: An optical device and a method of manufacturing the optical device, with the method including the steps of forming a dopant layer on a stoichiometric lithium niobate single crystal substrate with Li to Nb mole composition ratio of 49.5% to 50.5%, and diffusing a dopant in the dopant layer into at least a portion of the stoichiometric lithium niobate single crystal substrate. The stoichiometric lithium niobate single crystal substrate includes 0.5 to 5 mol % of Mg. In the diffusing step, a heat treatment is performed at a diffusion temperature of 1000° C. to 1200° C. for a diffusion time of 3 hours to 24 hours in a dry atmosphere of at least one of O2, N2, Ar and He gas having a dew-point temperature of ?35° C. or less.Type: GrantFiled: March 3, 2006Date of Patent: July 26, 2011Assignees: Sumitomo Osaka Cement Co., Ltd., National Institute for Materials ScienceInventors: Futoshi Yamamoto, Katsutoshi Kondou, Junichiro Ichikawa, Masaru Nakamura, Sunao Kurimura, Shunji Takekawa, Kenji Kitamura
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Patent number: 7878205Abstract: A manufacturing method for quasi phase matching (QPM) wavelength converter elements using crystal quartz as a base material in which twins are periodically induced, comprises a step of periodically inducing the twins by applying a stress onto a crystal quartz substrate as the base material so that an angle ? of a direction in which the stress is applied relative to a Z axis of the crystal quartz is 60°<?<90°.Type: GrantFiled: October 5, 2007Date of Patent: February 1, 2011Assignees: National Institute for Materials Science, Nidek Co., Ltd.Inventors: Sunao Kurimura, Tsuyoshi Yamada
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Publication number: 20100110534Abstract: A wavelength conversion element is provided as one including a monocrystalline nonlinear optical crystal. The nonlinear optical crystal has: a plurality of first regions having a polarity direction along a predetermined direction; a plurality of second regions having a polarity direction opposite to the predetermined direction; an entrance face into which a fundamental incident wave having a wavelength ? and a frequency ? is incident in a direction substantially perpendicular to the predetermined direction; and an exit face from which a second harmonic with a frequency 2? generated in the crystal emerges. The plurality of first and second regions are formed as alternately arranged in a period substantially equal to d expressed by a predetermined expression, between the entrance face and the exit face.Type: ApplicationFiled: October 16, 2009Publication date: May 6, 2010Applicants: Nikon Corporation, National Institute for Materials ScienceInventors: Kenichi Muramatsu, Sunao Kurimura
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Patent number: 7689067Abstract: A nested modulator is provided where the circuit arrangement of modifying electrodes including signal electrodes is simplified, and at the same time, the drive voltage can be lowered.Type: GrantFiled: November 7, 2007Date of Patent: March 30, 2010Assignees: Sumitomo Osaka Cement Co., Ltd., National Institute for Materials Science, National Institute of Information and Communications TechnologyInventors: Junichiro Ichikawa, Kaoru Higuma, Futoshi Yamamoto, Satoshi Oikawa, Shingo Mori, Sunao Kurimura, Kenji Kitamura, Tetsuya Kawanishi, Masahiro Tsuchiya, Masayuki Izutsu
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Patent number: 7446930Abstract: A problem to be solved is to provide a method of forming domain inverted regions of short period in a ferroelectric single crystal in a controllable time period of application of voltage and an optical wavelength conversion element using the same. A solving means of it solves the problem by forming (i) a control layer having a larger defect density Dcont1 than the defect density Dferro of a ferroelectric single crystal (Dferro<Dcont1) or forming (ii) a control layer having a lower degree of order of lattice points than the degree of order of lattice points of the ferroelectric single crystal on a face perpendicular to the direction of polarization of the ferroelectric single crystal in the ferroelectric single crystal.Type: GrantFiled: November 10, 2004Date of Patent: November 4, 2008Assignee: National Institute for Materials ScienceInventors: Kenji Kitamura, Sunao Kurimura, Masaru Nakamura, Shunji Takekawa, Kazuya Terabe, Shunichi Hishida, Tamaki Shimura
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Publication number: 20080212915Abstract: A nested modulator is provided where the circuit arrangement of modifying electrodes including signal electrodes is simplified, and at the same time, the drive voltage can be lowered.Type: ApplicationFiled: November 7, 2007Publication date: September 4, 2008Applicants: Sumitomo Osaka Cement Co., Ltd., National Institute for Materials Science, National Institute of Information and Communications TechnologyInventors: Junichiro Ichikawa, Kaoru Higuma, Futoshi Yamamoto, Satoshi Oikawa, Shingo Mori, Sunao Kurimura, Kenji Kitamura, Tetsuya Kawanishi, Masahiro Tsuchiya, Masayuki Izutsu
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Patent number: 7413430Abstract: The upper block 12 contacts the bearing block 20, and the bearing block 20 is coupled to the upper plate 21. The upper block 12 has a protruding part 22 on the upper surface that is worked into a convex surface with a radius of R1, and the bearing block 20 has a recessed part 23 in the undersurface that is worked into a concave surface with a radius of R2 (R2>R1). As a result of such a construction being used, the pressing surface of the upper pressing plate 15 always conforms to the surface of the quartz crystal substrate 11 during pressing, so that a uniform load is applied to the quartz crystal substrate 11. As a result, the surface of the quartz crystal can be uniformly pressed in the hot pressing method.Type: GrantFiled: September 18, 2003Date of Patent: August 19, 2008Assignee: National Institute for Materials ScienceInventors: Sunao Kurimura, Masaki Harada
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Patent number: 7403327Abstract: A wavelength conversion element having multi-gratings free from damage propagation and a light generating apparatus using it, and a wavelength conversion element having multi-gratings to make a thermal distribution centrosymmetric, and being free from damage propagation, are provided. The wavelength conversion element is realized by comprising a holder and plural prismatic ferroelectric single crystals disposed in the holder, wherein plural prismatic ferroelectric single crystals have at least five planes; the aspect ratios of planes perpendicular to respective longitudinal directions of the plural prismatic ferroelectric single crystals are virtually unity; and each of the plural prismatic ferroelectric single crystals has a domain inversion structure with a predetermined period in the direction perpendicular to the polarization direction thereof, and is arranged in a way that said direction perpendicular to the polarization direction is the same as those of the other crystals.Type: GrantFiled: November 19, 2004Date of Patent: July 22, 2008Assignee: National Institute for Materials ScienceInventors: Kenji Kitamura, Sunao Kurimura, Masaru Nakamura, Shunji Takekawa
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Publication number: 20080046043Abstract: A manufacturing method for quasi phase matching (QPM) wavelength converter elements using crystal quartz as a base material in which twins are periodically induced, comprises a step of periodically inducing the twins by applying a stress onto a crystal quartz substrate as the base material so that an angle ? of a direction in which the stress is applied relative to a Z axis of the crystal quartz is 60°<?<90°.Type: ApplicationFiled: October 5, 2007Publication date: February 21, 2008Applicants: NATIONAL INSTITUTE FOR MATERIALS SCIENCE, NIDEK CO., LTD.Inventors: Sunao Kurimura, Tsuyoshi Yamada