Patents by Inventor Shigeru Nakagawa

Shigeru Nakagawa 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).

  • Publication number: 20050179051
    Abstract: A light emitting device includes an n-type semiconductor layer, an active layer for generating light, the active layer being in electrical contact with the n-type semiconductor layer. A p-type semiconductor layer is in electrical contact with the active layer, and a p-electrode is in electrical contact with the p-type semiconductor layer. The p-electrode includes a layer of silver. In a preferred embodiment of the present invention, the n-type semiconductor layer and the p-type semiconductor layer are constructed from group III nitride semiconducting materials. In one embodiment of the invention, the silver layer is sufficiently thin to be transparent. In other embodiments, the silver layer is thick enough to reflect most of the light incident thereon. A fixation layer may be provided. The fixation layer may be a dielectric or a conductor.
    Type: Application
    Filed: April 11, 2005
    Publication date: August 18, 2005
    Inventors: You Kondoh, Satoshi Watanabe, Yawara Kaneko, Shigeru Nakagawa, Norihide Yamada
  • Patent number: 6900472
    Abstract: A light emitting device is constructed on a substrate. The device includes an n-type semiconductor layer in contact with the substrate, an active layer for generating light, the active layer being in electrical contact with the n-type semiconductor layer. A p-type semiconductor layer is in electrical contact with the active layer, and a p-electrode is in electrical contact with the p-type semiconductor layer. The p-electrode includes a layer of silver in contact with the p-type semiconductor layer. A bonding layer is formed overlying the silver layer to make an electrical connection to the silver layer. The silver layer may be thin and transparent or thicker (greater than 20 nm) and reflective.
    Type: Grant
    Filed: January 16, 2001
    Date of Patent: May 31, 2005
    Assignee: Lumileds Lighting U.S., LLC
    Inventors: You Kondoh, Satoshi Watanabe, Yawara Kaneko, Shigeru Nakagawa, Norihide Yamada
  • Publication number: 20050052726
    Abstract: An optical module, which is arranged in an optical transmission path, includes an optical amplifying unit configured with a semiconductor, wherein the optical amplifying unit amplifies light input from the optical transmission path, and an optical element configured with a semiconductor, wherein the optical element propagates the light amplified by the optical amplifying unit to the optical transmission path.
    Type: Application
    Filed: November 13, 2003
    Publication date: March 10, 2005
    Applicant: FiBest, Ltd.
    Inventors: Shigeru Nakagawa, Haruhisa Soda
  • Patent number: 6841407
    Abstract: A method for aperturing a vertical-cavity surface-emitting laser (VCSEL), for increasing the external quantum efficiency and decreasing the threshold current, involves an etching mixture that is applied to the active region of the VCSEL. The etching mixture is designed in a manner to selectively etch the active region of the VCSEL at a rate substantially faster than the etch rate of at least one of the multiple DBRS associated with the VCSEL.
    Type: Grant
    Filed: August 21, 2001
    Date of Patent: January 11, 2005
    Assignee: The Regents of the University of California
    Inventors: Larry A. Coldren, Eric M. Hall, Shigeru Nakagawa, Guilhem Almuneau
  • Patent number: 6810064
    Abstract: A system and a method for reducing the temperature in a vertical-cavity surface-emitting laser (VCSEL) comprising of including at least one heat spreading layer adjecent to one of the reflecting surfaces in a VCSEL. The heat spreading layer has high thermal conductivity allowing heat to bypass said one of the reflecting surfaces, thereby efficiently removing the heat away from the device. This also reduces the serial resistance and the thermal impedance of the VCSEL.
    Type: Grant
    Filed: August 21, 2001
    Date of Patent: October 26, 2004
    Assignee: The Regents of the University of California
    Inventors: Larry A. Coldren, Eric M. Hall, Shigeru Nakagawa
  • Publication number: 20040081389
    Abstract: A directional coupler type optical modulator with traveling-wave electrodes includes a first directional coupler region, a waveguide wave coupling region, a second directional coupler region, and a set of noncrossing traveling-wave electrodes disposed along the outside of the waveguides. The electrodes of each directional coupler are connected to the traveling-wave electrodes via air-bridges. The waveguide structures are of the P-I-N type having a common N-type conducting layer which provides delta-beta operation of the directional coupler, and both cross and bar states are controlled by a single input signal.
    Type: Application
    Filed: September 5, 2003
    Publication date: April 29, 2004
    Applicant: FiBest. Ltd.
    Inventors: Haruhisa Soda, Shigeru Nakagawa
  • Patent number: 6714573
    Abstract: A vertical cavity surface emitting laser (VCSEL) includes a semiconductor device having a pair of mirror portions, an active region, a tunnel junction, a pair of cladding layers and a substrate. Heat generated by the VCSEL dissipates through the cladding layers, which utilize an indium phosphide material. The VCSEL also includes selective etches that are used to aperture the active region to allow electric current to be injected into the active region.
    Type: Grant
    Filed: August 21, 2001
    Date of Patent: March 30, 2004
    Assignee: The Regents of the University of California
    Inventors: Larry A. Coldren, Eric M. Hall, Shigeru Nakagawa
  • Patent number: 6687281
    Abstract: A vertical cavity surface emitting laser (VCSEL) includes a semiconductor device having a pair of mirror portions, an active region, a tunnel junction, a pair of cladding layers and a substrate. Heat generated by the VCSEL dissipates through the cladding layers, which utilize an indium phosphide material. The VCSEL also includes selective etches that are used to aperture the active region to allow electric current to be injected into the active region.
    Type: Grant
    Filed: August 21, 2001
    Date of Patent: February 3, 2004
    Assignee: The Regents of the University of California
    Inventors: Larry A. Coldren, Eric M. Hall, Shigeru Nakagawa
  • Patent number: 6486984
    Abstract: A method and a system for monitoring specific channels in a WDM system involve splitting a WDM signal into multiple parallel signals, filtering the parallel signals with corresponding individually tunable filters in order to pass specific channels to each filter, and then detecting the presence of passed channels with dedicated detectors that correspond to the tunable filters. In a preferred embodiment, the initial WDM signal is demultiplexed by wavelength into multiple different transmission groups and each filter can be individually tuned over a channel range that corresponds to the range of channels within the transmission group that is directed to the filter. The preferred individually tunable filters are vertical cavity filters formed utilizing semiconductor wafer processing techniques, and the preferred photodetectors are simple low cost single-cell photodetectors.
    Type: Grant
    Filed: June 7, 1999
    Date of Patent: November 26, 2002
    Assignee: Agilent Technologies, Inc.
    Inventors: Douglas M. Baney, Norihide Yamada, Satoshi Watanabe, Shigeru Nakagawa, Yoshikatsu Ichimura
  • Publication number: 20020150129
    Abstract: A tunable VCSEL assembly comprises a first substrate upon which a first epitaxial structure is formed, the first epitaxial structure having areas of different optical properties comprising a front mirror or reflector, an active region, a cavity and a rear surface. A back subassembly comprises a second substrate upon which a second epitaxial structure is formed, the second epitaxial structure having areas of different optical properties and comprising a back movable mirror or reflector having a forward surface. Bonding elements or materials are emplaced at selected spaced apart corresponding areas on each of the front subassembly and the back subassembly such that upon engagement, the front subassembly and the back subassembly are permanently bonded to one another. The front subassembly and the back subassembly are configured such that there is an elastic optically transparent gap between the front surface of the back movable mirror of the back subassembly and the rear surface of the front subassembly.
    Type: Application
    Filed: April 16, 2001
    Publication date: October 17, 2002
    Inventors: Larry A. Coldren, Eric Michael Hall, Shigeru Nakagawa
  • Publication number: 20020150130
    Abstract: A tunable VCSEL assembly comprises a first substrate upon which a first epitaxial structure is formed, the first epitaxial structure having areas of different optical properties comprising a front mirror or reflector, an active region, a cavity and a rear surface. A back subassembly comprises a second substrate upon which a second epitaxial structure is formed, the second epitaxial structure having areas of different optical properties and comprising a back movable mirror or reflector having a forward surface. Bonding elements or materials are emplaced at selected spaced apart corresponding areas on each of the front subassembly and the back subassembly such that upon engagement, the front subassembly and the back subassembly are permanently bonded to one another. The front subassembly and the back subassembly are configured such that there is an elastic optically transparent gap between the front surface of the back movable mirror of the back subassembly and the rear surface of the front subassembly.
    Type: Application
    Filed: April 16, 2001
    Publication date: October 17, 2002
    Inventors: Larry A. Coldren, Eric Michael Hall, Shigeru Nakagawa
  • Publication number: 20020128882
    Abstract: This system comprises a usage status detection means for detecting the usage status of a vehicle, data input means for inputting data relating to the maintenance or management of a vehicle, and insurance premium calculation means for calculating vehicle insurance premiums based on detection results and inputted data.
    Type: Application
    Filed: February 27, 2002
    Publication date: September 12, 2002
    Applicant: TOYOTA JIDOSHA KABUSHIKI KAISHA
    Inventors: Shigeru Nakagawa, Kenji Mori, Akira Shinada, Katsuhiko Nunokawa, Hiroaki Okajima, Makoto Sasaki
  • Publication number: 20020101894
    Abstract: A method for aperturing a vertical-cavity surface-emitting laser (VCSEL), for increasing the external quantum efficiency and decreasing the threshold current, involves an etching mixture that is applied to the active region of the VCSEL. The etching mixture is designed in a manner to selectively etch the active region of the VCSEL at a rate substantially faster than the etch rate of at least one of the multiple DBRS associated with the VCSEL.
    Type: Application
    Filed: August 21, 2001
    Publication date: August 1, 2002
    Inventors: Larry A. Coldren, Eric M. Hall, Shigeru Nakagawa, Guilhem Almuneau
  • Publication number: 20020090016
    Abstract: A vertical cavity surface emitting laser (VCSEL) includes a semiconductor device having a pair of mirror portions, an active region, a tunnel junction, a pair of cladding layers and a substrate. Heat generated by the VCSEL dissipates through the cladding layers, which utilize an indium phosphide material. The VCSEL also includes selective etches that are used to aperture the active region to allow electric current to be injected into the active region.
    Type: Application
    Filed: August 21, 2001
    Publication date: July 11, 2002
    Inventors: Larry A. Coldren, Eric M. Hall, Shigeru Nakagawa
  • Publication number: 20020075926
    Abstract: A vertical cavity surface emitting laser (VCSEL) includes a semiconductor device having a pair of mirror portions, an active region, a tunnel junction, a pair of cladding layers and a substrate. Heat generated by the VCSEL dissipates through the cladding layers, which utilize an indium phosphide material. The VCSEL also includes selective etches that are used to aperture the active region to allow electric current to be injected into the active region.
    Type: Application
    Filed: August 21, 2001
    Publication date: June 20, 2002
    Inventors: Larry A. Coldren, Eric M. Hall, Jin K. Kim, Shigeru Nakagawa
  • Publication number: 20020071464
    Abstract: A vertical cavity surface emitting laser (VCSEL) includes a semiconductor device having a pair of mirror portions, an active region, a tunnel junction, a pair of cladding layers and a substrate. Heat generated by the VCSEL dissipates through the cladding layers, which utilize an indium phosphide material. The VCSEL also includes selective etches that are used to aperture the active region to allow electric current to be injected into the active region.
    Type: Application
    Filed: August 21, 2001
    Publication date: June 13, 2002
    Inventors: Larry A. Coldren, Eric M. Hall, Shigeru Nakagawa
  • Patent number: 6375255
    Abstract: A rear passenger seat adapted for use in a vehicle compartment, the passenger seat having a seat cushion the front end portion of which is supported by a support leg assembly pivotally mounted on a recessed portion of the compartment floor and the rear end portion of which is locked in place by means of a lock mechanism on a deck portion of the compartment floor, wherein the support leg assembly includes a support leg pivotally mounted on the recessed portion of the compartment floor for pivotal movement in a fore-and-aft direction, a leg support member pivoted at its lower end to an upper end of the support leg and pivoted at its upper end to a support frame of the seat cushion to be folded forward at the upper end of the support leg and retainer means provided on a vertical wall between the recessed portion and deck portion of the compartment floor for releasably retaining the support leg assembly in an upright position by engagement therewith, and wherein a pneumatic spring is disposed a between the leg su
    Type: Grant
    Filed: August 10, 2000
    Date of Patent: April 23, 2002
    Assignees: Toyota Jidosha Kabushiki Kaisha, Araco Kabushiki Kaisha, Kanto Jidosha Kogyo Kabushiki Kaisha
    Inventors: Tsutomu Maruta, Naoki Wakasugi, Shigeru Nakagawa
  • Publication number: 20010015442
    Abstract: A light emitting device is constructed on a substrate. The device includes an n-type semiconductor layer in contact with the substrate, an active layer for generating light, the active layer being in electrical contact with the n-type semiconductor layer. A p-type semiconductor layer is in electrical contact with the active layer, and a p-electrode is in electrical contact with the p-type semiconductor layer. The p-electrode includes a layer of silver in contact with the p-type semiconductor layer. A bonding layer is formed overlying the silver layer to make an electrical connection to the silver layer. The silver layer may be thin and transparent or thicker (greater than 20 nm) and reflective.
    Type: Application
    Filed: January 16, 2001
    Publication date: August 23, 2001
    Inventors: You Kondoh, Satoshi Watanabe, Yawara Kaneko, Shigeru Nakagawa, Norihide Yamada
  • Patent number: 6239490
    Abstract: A p-contact that comprises a contact layer of a p-type Group III-nitride semiconductor having an exposed surface and an electrode layer of palladium (Pd) located on the exposed surface of the contact layer. The p-contact is made by providing a p-type Group III-nitride semiconductor contact layer having an exposed surface, and depositing an electrode layer of palladium on the exposed surface of the contact layer. Preferably, the p-contact is annealed for a prolonged annealing time after the electrode layer is deposited, and the exposed surface of the contact layer is etched using hydrofluoric acid (HF) before depositing the electrode layer.
    Type: Grant
    Filed: February 9, 1998
    Date of Patent: May 29, 2001
    Assignee: Agilent Technologies, Inc.
    Inventors: Norihide Yamada, Shigeru Nakagawa, Yoshifumi Yamaoka, Tetsuya Takeuchi, Yawara Kaneki
  • Patent number: 6194743
    Abstract: A light emitting device constructed on a substrate. The device includes an n-type semiconductor layer in contact with the substrate, an active layer for generating light, the active layer being in electrical contact with the n-type semiconductor layer. A p-type semiconductor layer is in electrical contact with the active layer, and a p-electrode is in electrical contact with the p-type semiconductor layer. The p-electrode includes a layer of silver in contact with the p-type semiconductor layer. In the preferred embodiment of the present invention, the n-type semiconductor layer and the p-type semiconductor layer are constructed from group III nitride semiconductor materials. In one embodiment of the invention, the silver layer is sufficiently thin to be transparent. In other embodiments, the silver layer is thick enough to reflect most of the light incident thereon. A fixation layer is preferably provided over the silver layer.
    Type: Grant
    Filed: December 15, 1998
    Date of Patent: February 27, 2001
    Assignee: Agilent Technologies, Inc.
    Inventors: You Kondoh, Satoshi Watanabe, Yawara Kaneko, Shigeru Nakagawa, Norihide Yamada