Patents by Inventor Shigehisa Tanaka

Shigehisa Tanaka 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: 10978605
    Abstract: Provided are a semiconductor photodiode which achieves a higher response rate in a state in which light receiving sensitivity is maintained. The semiconductor photodiode includes a p-type semiconductor contact layer, an n-type semiconductor contact layer, and a light absorption layer. The light absorption layer includes a first semiconductor absorption layer having a thickness Wd and a p-type second semiconductor absorption layer having a thickness Wp. The first semiconductor absorption layer and the second absorption layer are made of the same composition. The first semiconductor absorption layer is depleted, and the second semiconductor absorption layer maintains an electric charge neutral condition except for a region near an interface with the first semiconductor absorption layer. A relationship between the thickness Wd and the thickness Wp satisfies 0.47?Wp/(Wp+Wd)?0.9.
    Type: Grant
    Filed: March 8, 2019
    Date of Patent: April 13, 2021
    Assignee: Lumentum Japan, Inc.
    Inventors: Takashi Toyonaka, Hiroshi Hamada, Shigehisa Tanaka
  • Patent number: 10921517
    Abstract: An electro-optic waveguide device may include a slot waveguide including a lower high-refractive-index layer with a first refractive index and an upper high-refractive-index layer with a second refractive index, wherein the lower high-refractive-index layer and the upper high-refractive-index layer have conductivity and are disposed to face each other with a gap; and a slot part formed as a low-refractive-index layer, wherein the low-refractive-index layer is formed of a material producing an electro-optic effect and has a third refractive index lower than the first refractive index and the second refractive index, wherein the low-refractive-index layer is formed in the gap to come into contact with the lower high-refractive-index layer and the upper high-refractive-index layer, and wherein one of the lower high-refractive-index layer or the upper high-refractive-index layer includes a stretch stretching on both sides of a contact portion with the slot part in a width direction intersecting a transmission dir
    Type: Grant
    Filed: August 26, 2019
    Date of Patent: February 16, 2021
    Assignee: Lumentum Japan, Inc.
    Inventors: Kensuke Ogawa, Hiroki Irie, Hiroaki Inoue, Takayoshi Fukui, Shigehisa Tanaka
  • Patent number: 10754108
    Abstract: An optical subassembly may have an optical waveguide for transmitting an optical signal, a lens element with a lens and a mirror integrated, a supporting element to which the optical waveguide and the lens element are attached, an optical element for converting the optical signal and an electric signal from one to another at least, and a substrate to which the optical element and the supporting element are attached.
    Type: Grant
    Filed: March 8, 2019
    Date of Patent: August 25, 2020
    Assignee: Lumentum Japan, Inc.
    Inventors: Yasunobu Matsuoka, Shigehisa Tanaka
  • Publication number: 20200064548
    Abstract: An electro-optic waveguide device may include a slot waveguide including a lower high-refractive-index layer with a first refractive index and an upper high-refractive-index layer with a second refractive index, wherein the lower high-refractive-index layer and the upper high-refractive-index layer have conductivity and are disposed to face each other with a gap; and a slot part formed as a low-refractive-index layer, wherein the low-refractive-index layer is formed of a material producing an electro-optic effect and has a third refractive index lower than the first refractive index and the second refractive index, wherein the low-refractive-index layer is formed in the gap to come into contact with the lower high-refractive-index layer and the upper high-refractive-index layer, and wherein one of the lower high-refractive-index layer or the upper high-refractive-index layer includes a stretch stretching on both sides of a contact portion with the slot part in a width direction intersecting a transmission dir
    Type: Application
    Filed: August 26, 2019
    Publication date: February 27, 2020
    Inventors: Kensuke OGAWA, Hiroki IRIE, Hiroaki INOUE, Takayoshi FUKUI, Shigehisa TANAKA
  • Publication number: 20190317284
    Abstract: An optical subassembly may have an optical waveguide for transmitting an optical signal, a lens element with a lens and a mirror integrated, a supporting element to which the optical waveguide and the lens element are attached, an optical element for converting the optical signal and an electric signal from one to another at least, and a substrate to which the optical element and the supporting element are attached.
    Type: Application
    Filed: March 8, 2019
    Publication date: October 17, 2019
    Inventors: Yasunobu MATSUOKA, Shigehisa TANAKA
  • Publication number: 20190280147
    Abstract: Provided are a semiconductor photodiode which achieves a higher response rate in a state in which light receiving sensitivity is maintained. The semiconductor photodiode includes a p-type semiconductor contact layer, an n-type semiconductor contact layer, and a light absorption layer. The light absorption layer includes a first semiconductor absorption layer having a thickness Wd and a p-type second semiconductor absorption layer having a thickness Wp. The first semiconductor absorption layer and the second absorption layer are made of the same composition. The first semiconductor absorption layer is depleted, and the second semiconductor absorption layer maintains an electric charge neutral condition except for a region near an interface with the first semiconductor absorption layer. A relationship between the thickness Wd and the thickness Wp satisfies 0.47?Wp/(Wp+Wd)?0.9.
    Type: Application
    Filed: March 8, 2019
    Publication date: September 12, 2019
    Inventors: Takashi TOYONAKA, Hiroshi HAMADA, Shigehisa TANAKA
  • Patent number: 10381799
    Abstract: An optical module includes a semiconductor laser with an active layer disproportionately positioned closer to the first surface. The semiconductor laser includes a reflector for reflecting the light outgoing from the active layer in a direction along the first surface toward another direction. The active layer and the reflector are monolithically integrated in the semiconductor laser. The optical module includes a carrier formed from a light transmissive material and having a third surface and a fourth surface opposite to each other. The semiconductor laser is mounted on the carrier so as for the light to enter the third surface. The carrier has a lens integrally on the fourth surface. The optical module includes a substrate having an optical waveguide and an optical coupler for guiding the light to the optical waveguide. The optical waveguide and the optical coupler are integrated in the substrate.
    Type: Grant
    Filed: April 3, 2018
    Date of Patent: August 13, 2019
    Assignee: Oclaro Japan, Inc.
    Inventors: Takanori Suzuki, Shigehisa Tanaka
  • Patent number: 10181694
    Abstract: An optical module includes a semiconductor optical device in which an active layer located at one side, an electrode located at the same side, and a mirror that reflects light toward the side opposite the electrode are monolithically integrated, a sub-mount having one surface on which a first wiring pattern is formed, a substrate in which an optical waveguide and a grating coupler are formed in a surface layer of the substrate, a spacer having an upper surface on which a second wiring pattern is formed, and a wire. The sub-mount is mounted on the spacer. The first wiring pattern on the sub-mount faces part of the second wiring pattern on the spacer and is electrically connected thereto. The second wiring pattern on the spacer includes a pad being disposed in a region exposed from the sub-mount and being bonded to the wire.
    Type: Grant
    Filed: August 30, 2017
    Date of Patent: January 15, 2019
    Assignee: Oclaro Japan, Inc.
    Inventors: Kohichi Robert Tamura, Takanori Suzuki, Mitsuo Akashi, Shigehisa Tanaka, Hiroaki Inoue, Hiroyasu Sasaki
  • Publication number: 20180294620
    Abstract: An optical module includes a semiconductor laser with an active layer disproportionately positioned closer to the first surface. The semiconductor laser includes a reflector for reflecting the light outgoing from the active layer in a direction along the first surface toward another direction. The active layer and the reflector are monolithically integrated in the semiconductor laser. The optical module includes a carrier formed from a light transmissive material and having a third surface and a fourth surface opposite to each other. The semiconductor laser is mounted on the carrier so as for the light to enter the third surface. The carrier has a lens integrally on the fourth surface. The optical module includes a substrate having an optical waveguide and an optical coupler for guiding the light to the optical waveguide. The optical waveguide and the optical coupler are integrated in the substrate.
    Type: Application
    Filed: April 3, 2018
    Publication date: October 11, 2018
    Inventors: Takanori SUZUKI, Shigehisa TANAKA
  • Publication number: 20170365977
    Abstract: An optical module includes a semiconductor optical device in which an active layer located at one side, an electrode located at the same side, and a mirror that reflects light toward the side opposite the electrode are monolithically integrated, a sub-mount having one surface on which a first wiring pattern is formed, a substrate in which an optical waveguide and a grating coupler are formed in a surface layer of the substrate, a spacer having an upper surface on which a second wiring pattern is formed, and a wire. The sub-mount is mounted on the spacer. The first wiring pattern on the sub-mount faces part of the second wiring pattern on the spacer and is electrically connected thereto. The second wiring pattern on the spacer includes a pad being disposed in a region exposed from the sub-mount and being bonded to the wire.
    Type: Application
    Filed: August 30, 2017
    Publication date: December 21, 2017
    Inventors: Kohichi Robert TAMURA, Takanori SUZUKI, Mitsuo AKASHI, Shigehisa TANAKA, Hiroaki INOUE, Hiroyasu SASAKI
  • Patent number: 9762026
    Abstract: An optical module includes a semiconductor optical device in which an active layer located at one side, an electrode located at the same side, and a mirror that reflects light toward the side opposite the electrode are monolithically integrated, a sub-mount having one surface on which a first wiring pattern is formed, a substrate in which an optical waveguide and a grating coupler are formed in a surface layer of the substrate, a spacer having an upper surface on which a second wiring pattern is formed, and a wire. The sub-mount is mounted on the spacer. The first wiring pattern on the sub-mount faces part of the second wiring pattern on the spacer and is electrically connected thereto. The second wiring pattern on the spacer includes a pad being disposed in a region exposed from the sub-mount and being bonded to the wire.
    Type: Grant
    Filed: August 18, 2016
    Date of Patent: September 12, 2017
    Assignee: OCLARO JAPAN, INC.
    Inventors: Kohichi Robert Tamura, Takanori Suzuki, Mitsuo Akashi, Shigehisa Tanaka, Hiroaki Inoue, Hiroyasu Sasaki
  • Publication number: 20170054269
    Abstract: An optical module includes a semiconductor optical device in which an active layer located at one side, an electrode located at the same side, and a mirror that reflects light toward the side opposite the electrode are monolithically integrated, a sub-mount having one surface on which a first wiring pattern is formed, a substrate in which an optical waveguide and a grating coupler are formed in a surface layer of the substrate, a spacer having an upper surface on which a second wiring pattern is formed, and a wire. The sub-mount is mounted on the spacer. The first wiring pattern on the sub-mount faces part of the second wiring pattern on the spacer and is electrically connected thereto. The second wiring pattern on the spacer includes a pad being disposed in a region exposed from the sub-mount and being bonded to the wire.
    Type: Application
    Filed: August 18, 2016
    Publication date: February 23, 2017
    Inventors: Kohichi Robert TAMURA, Takanori SUZUKI, Mitsuo AKASHI, Shigehisa TANAKA, Hiroaki INOUE, Hiroyasu SASAKI
  • Patent number: 8569727
    Abstract: The object of the invention included in the present application is to automatically prevent the deterioration of the image even when the image quality of the projected image is deteriorated due to the replacement of the light source or the like. The following light beam scanning image projection apparatus is one means for achieving the object.
    Type: Grant
    Filed: June 11, 2009
    Date of Patent: October 29, 2013
    Assignee: Hitachi, Ltd.
    Inventors: Etsuko Nomoto, Shigehisa Tanaka, Hitoshi Nakamura, Toshiki Sugawara, Kouji Nakahara
  • Patent number: 8124432
    Abstract: In an InGaN-based nitride semiconductor optical device having a long wavelength (440 nm or more) equal to or more than that of blue, the increase of a wavelength is realized while suppressing In (Indium) segregation and deterioration of crystallinity. In the manufacture of an InGaN-based nitride semiconductor optical device having an InGaN-based quantum well active layer including an InGaN well layer and an InGaN barrier layer, a step of growing the InGaN barrier layer includes: a first step of adding hydrogen at 1% or more to a gas atmosphere composed of nitrogen and ammonia and growing a GaN layer in the gas atmosphere; and a second step of growing the InGaN barrier layer in a gas atmosphere composed of nitrogen and ammonia.
    Type: Grant
    Filed: December 3, 2009
    Date of Patent: February 28, 2012
    Assignee: Opnext Japan, Inc.
    Inventors: Tomonobu Tsuchiya, Shigehisa Tanaka, Akihisa Terano, Kouji Nakahara
  • Publication number: 20110096383
    Abstract: The object of the invention included in the present application is to automatically prevent the deterioration of the image even when the image quality of the projected image is deteriorated due to the replacement of the light source or the like. The following light beam scanning image projection apparatus is one means for achieving the object.
    Type: Application
    Filed: June 11, 2009
    Publication date: April 28, 2011
    Inventors: Etsuko Nomoto, Shigehisa Tanaka, Hitoshi Nakamura, Toshiki Sugawara, Kouji Nakahara
  • Publication number: 20100328753
    Abstract: An integrated semiconductor optical device and an optical module capable of the high-speed and large-capacity optical transmission are provided. In an integrated semiconductor optical device in which a plurality of optical devices buried with semi-insulating semiconductor materials are integrated on the same semiconductor substrate and an optical module using the integrated semiconductor optical device, configurations (material and electrical characteristics) of the buried layers are made different for each of the optical devices.
    Type: Application
    Filed: June 24, 2010
    Publication date: December 30, 2010
    Inventors: Hiroaki Hayashi, Shigeki Makino, Takeshi Kitatani, Shigehisa Tanaka
  • Publication number: 20100150194
    Abstract: In an InGaN-based nitride semiconductor optical device having a long wavelength (440 nm or more) equal to or more than that of blue, the increase of a wavelength is realized while suppressing In (Indium) segregation and deterioration of crystallinity. In the manufacture of an InGaN-based nitride semiconductor optical device having an InGaN-based quantum well active layer including an InGaN well layer and an InGaN barrier layer, a step of growing the InGaN barrier layer includes: a first step of adding hydrogen at 1% or more to a gas atmosphere composed of nitrogen and ammonia and growing a GaN layer in the gas atmosphere; and a second step of growing the InGaN barrier layer in a gas atmosphere composed of nitrogen and ammonia.
    Type: Application
    Filed: December 3, 2009
    Publication date: June 17, 2010
    Applicant: OPNEXT JAPAN, INC.
    Inventors: Tomonobu TSUCHIYA, Shigehisa TANAKA, Akihisa TERANO, Kouji NAKAHARA
  • Patent number: 7738521
    Abstract: A super-lattice structure is used for a portion of a laser device of a self-aligned structure to lower the resistance of the device by utilizing the extension of electric current in the layer, paying attention to the fact that the lateral conduction of high density doping in the super-lattice structure is effective for decreasing the resistance of the laser, in order to lower the operation voltage and increase the power in nitride type wide gap semiconductor devices in which crystals with high carrier density are difficult to obtain and the device resistance is high.
    Type: Grant
    Filed: November 30, 2006
    Date of Patent: June 15, 2010
    Assignee: Opnext Japan, Inc.
    Inventors: Shin'ichi Nakatsuka, Tsukuru Ohtoshi, Kazunori Shinoda, Akihisa Terano, Hitoshi Nakamura, Shigehisa Tanaka
  • Patent number: 7668217
    Abstract: The present invention provides a Be-based group II-VI semiconductor laser using an InP substrate and having a stacked structure capable of continuous oscillation at a room temperature. A basic structure of a semiconductor laser is constituted by using a Be-containing lattice-matched II-VI semiconductor above an InP substrate. An active laser, an optical guide layer, and a cladding layer are constituted in a double hetero structure having a type I band line-up in order to enhance the injection efficiency of carriers to the active layer. Also, the active layer, the optical guide layer, and the cladding layer, which are capable of enhancing the optical confinement to the active layer, are constituted, and the cladding layer is constituted with bulk crystals.
    Type: Grant
    Filed: July 30, 2007
    Date of Patent: February 23, 2010
    Assignees: Hitachi, Ltd., Sophia School Corporation, Sony Corporation
    Inventors: Katsumi Kishino, Ichiro Nomura, Tsunenori Asatsuma, Hitoshi Nakamura, Tsukuru Ohtoshi, Takeshi Kikawa, Sumiko Fujisaki, Shigehisa Tanaka
  • Patent number: 7596160
    Abstract: A nitride semiconductor laser which features low resistance and high reliability. A buried layer is formed by selective growth and the shape of a p-type cladding layer is inverted trapezoidal so that the resistance of the p-type cladding layer and that of a p-type contact layer are decreased. For long-term reliability of the laser, the buried layer is a high-resistance semi-insulating layer which suppresses increase in leak current.
    Type: Grant
    Filed: August 20, 2007
    Date of Patent: September 29, 2009
    Assignee: Opnext Japan, Inc.
    Inventors: Tomonobu Tsuchiya, Shigehisa Tanaka, Akihisa Terano