Patents by Inventor Tomoki Ono

Tomoki Ono 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: 7167489
    Abstract: According to an aspect of the present invention, a nitride semiconductor laser device includes a nitride semiconductor active layer, and a stripe-shaped waveguide for guiding light generated in the active layer. At least one pair of light-absorbing films are provided in at least local regions on the opposite sides of the stripe-shaped waveguide, to reach a distance within 0.3 ?m from the waveguide. According to another aspect of the present invention, a gan-based semiconductor laser device includes first conductivity type semiconductor layers, a semiconductor active layer and second conductivity type semiconductor layers stacked sequentially. The laser device further includes a ridge stripe provided to cause a refractive index difference for confinement of light in a lateral direction crossing a longitudinal direction of a cavity, and a current-introducing window portion provided on the ridge stripe.
    Type: Grant
    Filed: July 18, 2002
    Date of Patent: January 23, 2007
    Assignee: Sharp Kabushiki Kaisha
    Inventors: Toshiyuki Kawakami, Yukio Yamasaki, Tomoki Ono, Shigetoshi Ito, Susumu Omi
  • Publication number: 20050213436
    Abstract: In a read/write device for writing and reading a storage medium by way of a heat assisted magnetic recording/reproduction scheme, the read/write device including an elevated slider provided with a semiconductor laser, provided is a heat dissipation mechanism for dissipating heat generated in the elevated slider to an outside of a housing of the read/write device. Further, the storage medium has a second heatsink layer formed of an Al film having a thickness of 50 ?m, a backing layer, a heat barrier layer, a first heatsink layer, a magnetic recording layer, and a protection film on a glass substrate. With this arrangement, in a read/write device which performs a heat assisted magnetic recording and reproduction by a semiconductor laser provided on the elevated slider, the occurrence of malfunction due to temperature rises in the storage medium is prevented.
    Type: Application
    Filed: March 29, 2005
    Publication date: September 29, 2005
    Inventors: Tomoki Ono, Naoyasu Iketani
  • Patent number: 6888867
    Abstract: A semiconductor laser device includes a substrate and an n-GaN layer composed of a nitride semiconductor formed on the substrate. The substrate includes a trench having as a slope a plane inclined 62 degrees from the main plane of the substrate, or a plane inclined within 3 degrees in an arbitrary direction from the inclined plane. The n-GaN layer is formed on the slope. On the n-GaN layer are formed a lower clad layer, an active layer, and an upper clad layer, each composed of a nitride semiconductor. The active layer has a plane orientation substantially matching the plane orientation of the main plane.
    Type: Grant
    Filed: March 26, 2002
    Date of Patent: May 3, 2005
    Assignees: Sharp Kabushiki Kaisha
    Inventors: Nobuhiko Sawaki, Yoshio Honda, Norifumi Kameshiro, Masahito Yamaguchi, Norikatsu Koide, Shigetoshi Ito, Tomoki Ono, Katsuki Furukawa
  • Publication number: 20050030995
    Abstract: In a GaN-based laser device (100) having a GaN-based semiconductor stacked-layered structure including a light emitting layer (106), the semiconductor stacked-layered structure includes a ridge stripe structure (111) causing a stripe-shaped waveguide, and has side surfaces (117, 118) opposite to each other to sandwich the stripe-shaped waveguide in its width direction therebetween. At least part of at least one of the side surfaces (117, 118) is processed to prevent the stripe-shaped waveguide from functioning as a Fabry-Perot resonator in the width direction.
    Type: Application
    Filed: September 1, 2004
    Publication date: February 10, 2005
    Applicant: SHARP KABUSHIKI KAISHA
    Inventors: Toshiyuki Kawakami, Tomoki Ono, Shigetoshi Ito, Susumu Omi
  • Publication number: 20040245537
    Abstract: According to an aspect of the present invention, a nitride semiconductor laser device includes a nitride semiconductor active layer (106), and a stripe-shaped waveguide for guiding light generated in the active layer. At least one pair of light-absorbing films (112) are provided in at least local regions on the opposite sides of the stripe-shaped waveguide, to reach a distance within 0.3 &mgr;m from the waveguide. According to another aspect of the present invention, a GaN-based semiconductor laser device includes first conductivity type semiconductor layers (103-105), a semiconductor active layer (106) and second conductivity type semiconductor layers (107-110) stacked sequentially. The laser device further includes a ridge stripe (111) provided to cause a refractive index difference for confinement of light in a lateral direction crossing a longitudinal direction of a cavity, and a current-introducing window portion (114) provided on the ridge stripe.
    Type: Application
    Filed: March 18, 2004
    Publication date: December 9, 2004
    Inventors: Toshiyuki Kawakami, Yukio Yamasaki, Tomoki Ono, Shigetoshi Ito, Susumu Omi
  • Publication number: 20040099870
    Abstract: A nitride semiconductor light emitting device includes at least a substrate, an active layer formed of a nitride semiconductor containing mainly In and Ga, a p-electrode and an n-electrode. At least one of the p-electrode and n-electrode is electrically separated into at least two regions.
    Type: Application
    Filed: November 20, 2003
    Publication date: May 27, 2004
    Applicant: SHARP KABUSHIKI KAISHA
    Inventors: Tomoki Ono, Shigetoshi Ito, Toshiyuki Okumura, Hirokazu Mouri, Kyoko Matsuda, Toshiyuki Kawakami, Takeshi Kamikama, Yoshihiko Tani
  • Patent number: 6735231
    Abstract: A semiconductor laser device includes an active layer and a layer greater in bandgap energy than the active layer and having a stacked-layer structure mainly of gallium-nitride-based semiconductor for lasing. This device includes a gallium-nitride-based semiconductor layer substantially equal in bandgap to the active layer and containing at least one element selected from the group consisting of As, P and Sb for saturable absorption at a location apart from the active layer and inside the layer greater in bandgap energy than the active layer.
    Type: Grant
    Filed: November 9, 2001
    Date of Patent: May 11, 2004
    Assignee: Sharp Kabushiki Kaisha
    Inventors: Tomoki Ono, Shigetoshi Ito
  • Patent number: 6593595
    Abstract: A semiconductor light-emitting device of the present invention includes: a substrate; a light-emitting layer provided above the substrate; and a saturable absorbing layer provided above the substrate, the saturable absorbing layer having characteristics in which saturation of light absorption occurs. The semiconductor light-emitting device has self-pulsation characteristics due to the saturable absorbing layer, and the semiconductor light-emitting device is characterized in that the saturable absorbing layer is doped with carbon.
    Type: Grant
    Filed: February 12, 2002
    Date of Patent: July 15, 2003
    Assignee: Sharp Kabushiki Kaisha
    Inventors: Tomoki Ono, Shigetoshi Ito
  • Publication number: 20030031219
    Abstract: A semiconductor laser device includes a substrate and an n-GaN layer composed of a nitride semiconductor formed on the substrate. The substrate includes a trench having as a slope a plane inclined 62 degrees from the main plane of the substrate, or a plane inclined within 3 degrees in an arbitrary direction from the inclined plane. The n-GaN layer is formed on the slope. On the n-GaN layer are formed a lower clad layer, an active layer, and an upper clad layer, each composed of a nitride semiconductor. The active layer has a plane orientation substantially matching the plane orientation of the main plane.
    Type: Application
    Filed: March 26, 2002
    Publication date: February 13, 2003
    Inventors: Nobuhiko Sawaki, Yoshio Honda, Norifumi Kameshiro, Masahito Yamaguchi, Norikatsu Koide, Shigetoshi Ito, Tomoki Ono, Katsuki Furukawa
  • Publication number: 20020181527
    Abstract: A semiconductor laser device includes an active layer and a layer greater in bandgap energy than the active layer and having a stacked-layer structure mainly of gallium-nitride-based semiconductor for lasing. This device includes a gallium-nitride-based semiconductor layer substantially equal in bandgap to the active layer and containing at least one element selected from the group consisting of As, P and Sb for saturable absorption at a location apart from the active layer and inside the layer greater in bandgap energy than the active layer.
    Type: Application
    Filed: November 9, 2001
    Publication date: December 5, 2002
    Inventors: Tomoki Ono, Shigetoshi Ito
  • Publication number: 20020158259
    Abstract: A semiconductor light-emitting device of the present invention includes: a substrate; a light-emitting layer provided above the substrate; and a saturable absorbing layer provided above the substrate, the saturable absorbing layer having characteristics in which saturation of light absorption occurs. The semiconductor light-emitting device has self-pulsation characteristics due to the saturable absorbing layer, and the semiconductor light-emitting device is characterized in that the saturable absorbing layer is doped with carbon.
    Type: Application
    Filed: February 12, 2002
    Publication date: October 31, 2002
    Inventors: Tomoki Ono, Shigetoshi Ito