Patents by Inventor Masaharu Doi

Masaharu Doi 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).

  • Patent number: 9520948
    Abstract: A substrate is a substrate on which a first optical modulator and a second optical modulator are arranged in parallel along a width direction. A first prism moves, to a side opposite to the second optical modulator along the width direction of the substrate, an optical path of the first output light and the second output light that are obtained by light of the first wavelength being modulated by the first optical modulator. A second prism is arranged at a position away from the first prism along a longitudinal direction of the substrate and moves, to a side opposite to the first modulator along the width direction of the substrate, an optical path of the third output light and the fourth output light that are obtained by the light of the second wavelength being modulated by the second optical modulator.
    Type: Grant
    Filed: February 6, 2015
    Date of Patent: December 13, 2016
    Assignee: FUJITSU OPTICAL COMPONENTS LIMITED
    Inventors: Masaharu Doi, Yoshinobu Kubota, Yoshitada Kawashima, Teruhiro Kubo
  • Patent number: 9487883
    Abstract: Trimanganese tetraoxide has high reactivity with a lithium compound, is excellent in handling efficiency, and is suitable as a manganese material of a lithium manganese oxide, and its production process. Trimanganese tetraoxide particles including trimanganese tetraoxide primary particles having an average primary particle size of at most 2 ?m agglomerated, the pore volume of pores being at least 0.4 mL/g. The most frequent pores are preferably pores having a diameter of at most 5 ?m. The trimanganese tetraoxide particles can be obtained by producing trimanganese tetraoxide particles, which includes directly crystallizing trimanganese tetraoxide from a manganese salt aqueous solution, wherein the manganese salt aqueous solution and an alkali aqueous solution are mixed so that the oxidation-reduction potential is at least 0 mV and OH?/Mn2+ (mol/mol) is at most 0.55, to obtain a slurry, and the solid content concentration of the slurry is adjusted to be at most 2 wt %.
    Type: Grant
    Filed: April 17, 2013
    Date of Patent: November 8, 2016
    Assignee: TOSOH CORPORATION
    Inventors: Eiichi Iwata, Miki Yamashita, Masaharu Doi
  • Publication number: 20160313510
    Abstract: An optical module includes a substrate on which an optical waveguide is formed, and an optical fiber assembly. The optical fiber assembly includes an optical fiber, a translucent member, and a mirror portion. The translucent member includes a joint surface joined to an end surface of the substrate at an end of the optical waveguide, and is attached to a distal end of the optical fiber. The mirror portion is formed on the translucent member, reflects light emitted from the distal end of the optical fiber in a direction different from a traveling direction of the light, and collects the reflected light into the end of the optical waveguide through the joint surface.
    Type: Application
    Filed: March 11, 2016
    Publication date: October 27, 2016
    Applicant: Fujitsu Optical Components Limited
    Inventors: Masaharu Doi, Akira Ishii, Teruhiro Kubo, Yoshinobu Kubota
  • Publication number: 20160223881
    Abstract: An optical modulator includes: a ferroelectric substrate in which an input optical waveguide, first and second optical waveguides, and an output optical waveguide are formed; a first electrode formed in a vicinity of the first optical waveguide and to which a first DC voltage is applied; a second electrode formed in a vicinity of the second optical waveguide and to which a second DC voltage is applied; a third electrode electrically connected to the first electrode and formed on both sides of the second electrode; and a fourth electrode electrically connected to the second electrode and formed on both sides of the first electrode. A first gap between the first electrode and the fourth electrode is approximately the same as a second gap between the second electrode and the third electrode. A gap between the third electrode and the fourth electrode is 1-5 times greater than the first gap.
    Type: Application
    Filed: November 19, 2015
    Publication date: August 4, 2016
    Applicant: FUJITSU OPTICAL COMPONENTS LIMITED
    Inventors: Masaharu DOI, YOSHIHIKO YOSHIDA, Yoshinobu KUBOTA, Yoshitada KAWASHIMA
  • Publication number: 20150261017
    Abstract: A substrate is a substrate on which a first optical modulator and a second optical modulator are arranged in parallel along a width direction. A first prism moves, to a side opposite to the second optical modulator along the width direction of the substrate, an optical path of the first output light and the second output light that are obtained by light of the first wavelength being modulated by the first optical modulator. A second prism is arranged at a position away from the first prism along a longitudinal direction of the substrate and moves, to a side opposite to the first modulator along the width direction of the substrate, an optical path of the third output light and the fourth output light that are obtained by the light of the second wavelength being modulated by the second optical modulator.
    Type: Application
    Filed: February 6, 2015
    Publication date: September 17, 2015
    Applicant: Fujitsu Optical Components Limited
    Inventors: Masaharu DOI, Yoshinobu Kubota, Yoshitada Kawashima, TERUHIRO KUBO
  • Publication number: 20150261019
    Abstract: An optical modulator includes a substrate, an electrode, and an optical waveguide. The substrate includes a flat portion and a protruding portion protruded from the flat portion. The electrode is supported by the protruding portion. The optical waveguide is formed inside the protruding portion and waveguides light to be modulated with a voltage applied to the electrode. The protruding portion contains a part, present on the side of the electrode, of a light distribution region over which the light waveguided by the optical waveguide is distributed. A height of a tip of the protruding portion from the flat portion is smaller than a width of the light distribution region along a protruding direction of the protruding portion. A width of the tip of the protruding portion is smaller than a width of the light distribution region along a direction perpendicular to the protruding direction of the protruding portion.
    Type: Application
    Filed: February 24, 2015
    Publication date: September 17, 2015
    Applicant: Fujitsu Optical Components Limited
    Inventors: Yoshihiko YOSHIDA, Masaharu Doi, Yoshinobu Kubota, Masaki Sugiyama
  • Publication number: 20150104373
    Abstract: Trimanganese tetraoxide has high reactivity with a lithium compound, is excellent in handling efficiency, and is suitable as a manganese material of a lithium manganese oxide, and its production process. Trimanganese tetraoxide particles including trimanganese tetraoxide primary particles having an average primary particle size of at most 2 ?m agglomerated, the pore volume of pores being at least 0.4 mL/g. The most frequent pores are preferably pores having a diameter of at most 5 ?m. The trimanganese tetraoxide particles can be obtained by producing trimanganese tetraoxide particles, which includes directly crystallizing trimanganese tetraoxide from a manganese salt aqueous solution, wherein the manganese salt aqueous solution and an alkali aqueous solution are mixed so that the oxidation-reduction potential is at least 0 mV and OH?/Mn2+ (mol/mol) is at most 0.55, to obtain a slurry, and the solid content concentration of the slurry is adjusted to be at most 2 wt %.
    Type: Application
    Filed: April 17, 2013
    Publication date: April 16, 2015
    Applicant: TOSOH CORPORATION
    Inventors: Eiichi Iwata, Miki Yamashita, Masaharu Doi
  • Patent number: 8805127
    Abstract: An optical waveguide device includes: a substrate which has an electro-optical effect; an optical waveguide which is formed on the substrate and/or inside the substrate; and an in-substrate electrode which is formed of a metal and provided inside the substrate.
    Type: Grant
    Filed: October 10, 2013
    Date of Patent: August 12, 2014
    Assignee: Fujitsu Limited
    Inventors: Tetsuya Miyatake, Takashi Shiraishi, Masaharu Doi
  • Patent number: 8774567
    Abstract: A polarization conversion device converts a polarization state of a light which is input to a first waveguide, that is, TE/TM mode of the light, to output it from the first waveguide. The polarization conversion device includes: a mode converter that performs the inter-conversion of TE/TM modes of the light which is input to the first waveguide; and a polarization separator that receives the light passed through the mode converter and separates the received light into a first light, TE/TM of which mode has been converted by the mode converter and a second light, TE/TM of which mode has not been converted, to output the first light to the first waveguide.
    Type: Grant
    Filed: August 30, 2012
    Date of Patent: July 8, 2014
    Assignee: Fujitsu Limited
    Inventors: Masaharu Doi, Kazuhiro Tanaka
  • Patent number: 8774583
    Abstract: An optical device and an optical transmitter are provided. The optical device includes a substrate, a first optical waveguide that may be formed in the substrate and may have a bending portion, and a second optical waveguide that intersects with the bending portion of the first optical waveguide, wherein a groove may be formed outside the bending portion of the first optical waveguide in the substrate.
    Type: Grant
    Filed: January 11, 2010
    Date of Patent: July 8, 2014
    Assignee: Fujitsu Limited
    Inventors: Takashi Shiraishi, Tetsu Hasegawa, Masaharu Doi
  • Publication number: 20140034602
    Abstract: An optical waveguide device includes: a substrate which has an electro-optical effect; an optical waveguide which is formed on the substrate and/or inside the substrate; and an in-substrate electrode which is formed of a metal and provided inside the substrate.
    Type: Application
    Filed: October 10, 2013
    Publication date: February 6, 2014
    Applicant: FUJITSU LIMITED
    Inventors: Tetsuya MIYATAKE, Takashi SHIRAISHI, Masaharu DOI
  • Patent number: 8582928
    Abstract: An optical waveguide device includes: a substrate which has an electro-optical effect; an optical waveguide which is formed on the substrate and/or inside the substrate; and an in-substrate electrode which is formed of a metal and provided inside the substrate.
    Type: Grant
    Filed: February 2, 2010
    Date of Patent: November 12, 2013
    Assignee: Fujitsu Limited
    Inventors: Tetsuya Miyatake, Takashi Shiraishi, Masaharu Doi
  • Publication number: 20130010345
    Abstract: A polarization conversion device converts a polarization state of a light which is input to a first waveguide, that is, TE/TM mode of the light, to output it from the first waveguide. The polarization conversion device includes: a mode converter that performs the inter-conversion of TE/TM modes of the light which is input to the first waveguide; and a polarization separator that receives the light passed through the mode converter and separates the received light into a first light, TE/TM of which mode has been converted by the mode converter and a second light, TE/TM of which mode has not been converted, to output the first light to the first waveguide.
    Type: Application
    Filed: August 30, 2012
    Publication date: January 10, 2013
    Applicant: FUJITSU LIMITED
    Inventors: Masaharu DOI, Kazuhiro Tanaka
  • Patent number: 8280200
    Abstract: A polarization conversion device converts a polarization state of a light which is input to a first waveguide, that is, TE/TM mode of the light, to output it from the first waveguide. The polarization conversion device includes: a mode converter that performs the inter-conversion of TE/TM modes of the light which is input to the first waveguide; and a polarization separator that receives the light passed through the mode converter and separates the received light into a first light, TE/TM of which mode has been converted by the mode converter and a second light, TE/TM of which mode has not been converted, to output the first light to the first waveguide.
    Type: Grant
    Filed: September 29, 2009
    Date of Patent: October 2, 2012
    Assignee: Fujitsu Limited
    Inventors: Masaharu Doi, Kazuhiro Tanaka
  • Patent number: 7941011
    Abstract: In a multilevel light intensity modulator of the invention, input light is branched into n (n is an integer of 2 or more), and respectively sent to n branching waveguides. On the branching waveguides are respectively provided MZI light modulating sections. The MZI light modulating sections branch the input light into two at a branching ratio different from 0.5:0.5, and respectively output a binary optical signal with a quenching ratio being deteriorated, by on/off driving with a binary electric signal. Then by coupling the light output from the MZI light modulating sections, an optical signal with the light intensity modulated to a 2n value not including the zero level is output. As a result quaternary or higher level light intensity modulation which does not include the zero level, can be realized by a practical configuration using a binary electric signal.
    Type: Grant
    Filed: September 18, 2009
    Date of Patent: May 10, 2011
    Assignee: Fujitsu Limited
    Inventor: Masaharu Doi
  • Patent number: 7893381
    Abstract: A welding set and a welding method that suppresses the unnecessary magnetization of a permanent magnet member by a welding current when welding one metal member including a permanent magnet member and the other metal member together are obtained. The welding set is provided with a work retaining part 3 that retains a work 14; a pressure device 4 located over the work retaining part 3 with a work-providing space interposed; a first welding electrode 8 mounted on a moving part 4a of the pressure device 4; a second welding electrode 10; and a welding transformer 11 that supplies a welding current to both of the welding electrodes 8, 10. Both of the welding electrodes 8, 10 are located on one end side of the work 14 with respect to one metal member and the other metal member respectively, as well as are located so that there is no permanent magnet member 18 between respective abutment terminal of one metal member and the other metal member.
    Type: Grant
    Filed: January 20, 2005
    Date of Patent: February 22, 2011
    Assignee: Mitsubishi Denki Kabushiki Kaisha
    Inventors: Masahiko Fujita, Shoichiro Nishitani, Yasushi Nakatake, Masaharu Doi, Shinya Kudou, Kazuhiro Shono, Yoshihito Asao, Masaru Kuribayashi
  • Patent number: 7787717
    Abstract: The present invention has an object to provide an optical device capable of leading out a light propagated through an optical waveguide to a desired substrate side face while maintaining the sufficient power of the light, within a range of limited substrate size. To this end, according to the optical device of the present invention, a groove is formed in the vicinity of an end portion on the optical output side of the optical waveguide, on the substrate on which the optical waveguide is formed, a side wall of the groove is used as a reflecting plane, the light output from the optical waveguide is reflected by the reflecting plane, and the reflected light is emitted from the desired substrate side face.
    Type: Grant
    Filed: May 7, 2008
    Date of Patent: August 31, 2010
    Assignee: Fujitsu Limited
    Inventors: Yasuhiro Ohmori, Shinji Maruyama, Tetsuo Ishizaka, Masaharu Doi
  • Publication number: 20100195953
    Abstract: An optical waveguide device includes: a substrate which has an electro-optical effect; an optical waveguide which is formed on the substrate and/or inside the substrate; and an in-substrate electrode which is formed of a metal and provided inside the substrate.
    Type: Application
    Filed: February 2, 2010
    Publication date: August 5, 2010
    Applicant: FUJITSU LIMITED
    Inventors: Tetsuya MIYATAKE, Takashi Shiraishi, Masaharu Doi
  • Publication number: 20100178064
    Abstract: An optical device and an optical transmitter are provided. The optical device includes a substrate, a first optical waveguide that may be formed in the substrate and may have a bending portion, and a second optical waveguide that intersects with the bending portion of the first optical waveguide, wherein a groove may be formed outside the bending portion of the first optical waveguide in the substrate.
    Type: Application
    Filed: January 11, 2010
    Publication date: July 15, 2010
    Applicant: FUJITSU LIMITED
    Inventors: Takashi SHIRAISHI, Tetsu Hasegawa, Masaharu Doi
  • Publication number: 20100142879
    Abstract: A polarization conversion device converts a polarization state of a light which is input to a first waveguide, that is, TE/TM mode of the light, to output it from the first waveguide. The polarization conversion device includes: a mode converter that performs the inter-conversion of TE/TM modes of the light which is input to the first waveguide; and a polarization separator that receives the light passed through the mode converter and separates the received light into a first light, TE/TM of which mode has been converted by the mode converter and a second light, TE/TM of which mode has not been converted, to output the first light to the first waveguide.
    Type: Application
    Filed: September 29, 2009
    Publication date: June 10, 2010
    Applicant: FUJITSU LIMITED
    Inventors: Masaharu Doi, Kazuhiro Tanaka