Patents by Inventor Norihiro Iwai

Norihiro Iwai 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: 10193305
    Abstract: A wavelength tunable laser device includes: a laser cavity formed of a grating and a reflecting mirror including a ring resonator filter; a gain portion; and a phase adjusting portion. The grating creates a first comb-shaped reflection spectrum. The ring resonator filter includes a ring-shaped waveguide and two arms and creates a second comb-shaped reflection spectrum having peaks of a narrower full width than peaks in the first comb-shaped reflection spectrum at a wavelength interval different from that of the first comb-shaped reflection spectrum. One of the peaks in the first comb-shaped reflection spectrum and one of the peaks in the second comb-shaped reflection spectrum are overlapped on a wavelength axis, and a spacing between cavity modes is narrower than the full width at half maximum of the peaks in the first comb-shaped reflection spectrum.
    Type: Grant
    Filed: September 19, 2017
    Date of Patent: January 29, 2019
    Assignee: FURUKAWA ELECTRIC CO., LTD.
    Inventors: Yasumasa Kawakita, Yasutaka Higa, Norihiro Iwai, Tatsuro Kurobe
  • Patent number: 9960572
    Abstract: A semiconductor device includes a semiconductor layer formed of a III-V group semiconductor crystal containing As as a primary component of a V group. A V group element other than As has been introduced at a concentration of 0.02 to 5% into a V group site of the III-V group semiconductor crystal in the semiconductor layer.
    Type: Grant
    Filed: August 12, 2016
    Date of Patent: May 1, 2018
    Assignee: FURUKAWA ELECTRIC CO., LTD.
    Inventors: Masayuki Iwami, Hirotatsu Ishii, Norihiro Iwai, Takeyoshi Matsuda, Akihiko Kasukawa, Takuya Ishikawa, Yasumasa Kawakita, Eisaku Kaji
  • Publication number: 20180026426
    Abstract: A wavelength tunable laser device includes: a laser cavity formed of a grating and a reflecting mirror including a ring resonator filter; a gain portion; and a phase adjusting portion. The grating creates a first comb-shaped reflection spectrum. The ring resonator filter includes a ring-shaped waveguide and two arms and creates a second comb-shaped reflection spectrum having peaks of a narrower full width than peaks in the first comb-shaped reflection spectrum at a wavelength interval different from that of the first comb-shaped reflection spectrum. One of the peaks in the first comb-shaped reflection spectrum and one of the peaks in the second comb-shaped reflection spectrum are overlapped on a wavelength axis, and a spacing between cavity modes is narrower than the full width at half maximum of the peaks in the first comb-shaped reflection spectrum.
    Type: Application
    Filed: September 19, 2017
    Publication date: January 25, 2018
    Applicant: FURUKAWA ELECTRIC CO., LTD.
    Inventors: Yasumasa KAWAKITA, Yasutaka HIGA, Norihiro IWAI, Tatsuro KUROBE
  • Publication number: 20160351392
    Abstract: A semiconductor device includes a semiconductor layer formed of a III-V group semiconductor crystal containing As as a primary component of a V group. A V group element other than As has been introduced at a concentration of 0.02 to 5% into a V group site of the III-V group semiconductor crystal in the semiconductor layer.
    Type: Application
    Filed: August 12, 2016
    Publication date: December 1, 2016
    Applicant: FURUKAWA ELECTRIC CO., LTD.
    Inventors: Masayuki IWAMI, Hirotatsu ISHII, Norihiro IWAI, Takeyoshi MATSUDA, Akihiko KASUKAWA, Takuya ISHIKAWA, Yasumasa KAWAKITA, Eisaku KAJI
  • Publication number: 20160352075
    Abstract: A semiconductor laser device includes an active layer including a well layer and a barrier layer formed of a III-V group semiconductor crystal containing As as a primary component of a V group. A V group element other than As has been introduced at a concentration of 0.02 to 5% into a V group site of the III-V group semiconductor crystal in at least one of the well layer and the barrier layer, and a III group site of the III-V group semiconductor crystal in at least one of the well layer and the barrier layer contains Al.
    Type: Application
    Filed: August 12, 2016
    Publication date: December 1, 2016
    Applicant: FURUKAWA ELECTRIC CO., LTD.
    Inventors: Masayuki IWAMI, Hirotatsu ISHII, Norihiro IWAI, Takeyoshi MATSUDA, Akihiko KASUKAWA, Takuya ISHIKAWA, Yasumasa KAWAKITA, Eisaku KAJI
  • Patent number: 8929692
    Abstract: Provided is an optical integrated device comprising a first waveguide that is formed on a substrate and includes a first optical path; an electrode formed on the first waveguide; a second waveguide that is formed on the substrate and includes a second optical path; and a transparent waveguide that is formed on the substrate between the first waveguide and the second waveguide, and includes a transparent core that serves as an optical path and is formed of a material having higher bandgap energy than the first optical path. The electrode is formed above the first waveguide and is not formed above the transparent waveguide, and elements including the first waveguide are optically active elements that operate according to current injected thereto.
    Type: Grant
    Filed: August 27, 2012
    Date of Patent: January 6, 2015
    Assignee: Furukawa Electric Co., Ltd.
    Inventors: Norihiro Iwai, Hirotatsu Ishii
  • Patent number: 8494022
    Abstract: A surface emitting laser is formed of a composition in which bandgap energy of layers from immediately above a current confinement layer to a second conductivity type contact layer is reduced towards the second conductivity type contact layer in a stacking direction, and a composition in which bandgap energy of layers from immediately below the current confinement layer to a first conductivity type contact layer is reduced towards the first conductivity type contact layer in a stacking direction while bypassing a quantum well layer or a quantum dot of an active layer, and includes a second conductivity type cladding layer including a material for reducing the mobility of carriers.
    Type: Grant
    Filed: March 30, 2011
    Date of Patent: July 23, 2013
    Assignee: Furukawa Electric Co., Ltd.
    Inventors: Hitoshi Shimizu, Takeo Kageyama, Keishi Takaki, Norihiro Iwai
  • Patent number: 8488644
    Abstract: A semiconductor laser element includes a first electrode, a second electrode, a first reflecting mirror, a second reflecting mirror, and a resonator. The resonator includes an active layer, a current confinement layer, a first semiconductor layer having a first doping concentration formed at a side opposite to the active layer across the current confinement layer, and a second semiconductor layer having a second doping concentration higher than the first doping concentration formed between the first semiconductor layer and the current confinement layer. The first electrode is provided to contact a part of a surface of the first semiconductor layer. The first semiconductor layer has a diffusion portion into which a component of the first electrode diffuses. The second semiconductor layer contacts the diffusion portion. The second semiconductor layer is positioned at a node of a standing wave at a time of laser oscillation of the semiconductor laser element.
    Type: Grant
    Filed: December 10, 2009
    Date of Patent: July 16, 2013
    Assignee: Furukawa Electric Co., Ltd.
    Inventors: Suguru Imai, Keishi Takaki, Norihiro Iwai, Kinuka Tanabe, Hitoshi Shimizu, Hirotatsu Ishii
  • Patent number: 8409998
    Abstract: According to a method of manufacturing a vertical-cavity surface-emitting semiconductor laser element in accordance with the present invention, a process of wet etching is performed for a part that is oxidized in a layer of an AlGaAs (42) which configures a layer having an index of refraction as lower and in which a composition of aluminum is designed to be as higher comparing to the other pairs of layers in a DBR mirror at an upper side that are formed at an inner side of a mesa post (38). And then a process of filling up again is performed with making use of a layer of polyimide (26). Moreover, an etchant that includes such as a hydrofluoric acid or a buffered hydrofluoric acid or an aqueous ammonia or the like is made use in order to perform such the process of wet etching.
    Type: Grant
    Filed: September 30, 2009
    Date of Patent: April 2, 2013
    Assignee: Furukawa Electric Co., Ltd
    Inventors: Kageyama Takeo, Norihiro Iwai, Koji Hiraiwa, Yoshihiko Ikenaga
  • Publication number: 20130064497
    Abstract: Provided is an optical integrated device comprising a first waveguide that is formed on a substrate and includes a first optical path; an electrode formed on the first waveguide; a second waveguide that is formed on the substrate and includes a second optical path; and a transparent waveguide that is formed on the substrate between the first waveguide and the second waveguide, and includes a transparent core that serves as an optical path and is formed of a material having higher bandgap energy than the first optical path. The electrode is formed above the first waveguide and is not formed above the transparent waveguide, and elements including the first waveguide are optically active elements that operate according to current injected thereto.
    Type: Application
    Filed: August 27, 2012
    Publication date: March 14, 2013
    Applicant: FURUKAWA ELECTRIC CO., LTD.
    Inventors: Norihiro IWAI, Hirotatsu ISHII
  • Publication number: 20120320447
    Abstract: There is provided a semiconductor laser that includes a dielectric multilayer mirror (116) with a structure including high-refractive-index dielectric layers and low-refractive-index dielectric layers arranged periodically, and a cavity (110) that includes the dielectric multilayer mirror (116), on at least one facet thereof, and an active layer (105). A non-linear layer that is non-linear with respect to primary mode laser light is formed in at least one layer of either the high-refractive-index dielectric layers or the low-refractive-index dielectric layers.
    Type: Application
    Filed: December 20, 2011
    Publication date: December 20, 2012
    Applicant: FURUKAWA ELECTRIC CO., LTD.
    Inventors: Keishi TAKAKI, Hirotatsu ISHII, Norihiro IWAI, Shinya OOTOMO
  • Patent number: 8270447
    Abstract: A semiconductor light emitting element, comprises: an active layer; a first electrode and second electrode that inject current to the active layer; a semiconductor layer between the active layer and the first electrode; and a dielectric layer that is provided on the semiconductor layer and through which light from the active layer passes; wherein the first electrode is provided on the semiconductor layer, has an opening through which light from the active layer passes, and comprises a first electrode layer that comes in contact with and is provided on the semiconductor layer, and a second electrode layer that is provided on the first electrode layer, with the first electrode layer having less reactivity with the semiconductor layer than the second electrode layer; and the dielectric layer is provided inside the opening such that the end section on the opening side of the first electrode layer extends from the top of the semiconductor layer to the top of the dielectric layer.
    Type: Grant
    Filed: January 7, 2010
    Date of Patent: September 18, 2012
    Assignee: Furukawa Electric Co., Ltd.
    Inventors: Naoki Tsukiji, Norihiro Iwai, Keishi Takaki, Koji Hiraiwa
  • Patent number: 8204093
    Abstract: A method of manufacturing a surface emitting laser element of a vertical cavity type comprises sequential accumulation that accumulates a reflecting mirror of a multilayered film layer at a lower side of the substrate, and accumulates semiconductor layers onto the reflecting minor at the lower side that comprises an active layer and a contact layer. The process includes forming a first layer of dielectric substance on the contact layer, forming an electrode of an annular shape on the contact layer that has an open part to be arranged for the first layer at an inner side of the open part, and forming a second layer of dielectric substance to cover the first layer and a gap formed between the first layer and the electrode of the annular shape. The accumulated semiconductor layers are etched to form a mesa post, using the electrode of the annular shape as a mask.
    Type: Grant
    Filed: September 16, 2009
    Date of Patent: June 19, 2012
    Assignee: The Furukawa Electric Co., Ltd.
    Inventors: Keishi Takaki, Norihiro Iwai, Koji Hiraiwa
  • Patent number: 8178364
    Abstract: A method of performing a wafer level burn-in test for a plurality of surface-emitting laser devices formed on a wafer includes causing a plurality of contact electrodes arranged in a same plane with a pitch same as that of the surface-emitting laser devices being electrically connected to each other to have contact with pad electrodes of the surface-emitting laser devices, respectively, and applying a current to second electrodes of the surface-emitting laser devices and the contact electrodes. The wafer level burn-in test is performed while heating the wafer at a predetermined temperature. Laser lights emitted from the surface-emitting laser devices are monitored during the wafer level burn-in test.
    Type: Grant
    Filed: June 8, 2010
    Date of Patent: May 15, 2012
    Assignee: Furukawa Electric Co., Ltd.
    Inventors: Koji Hiraiwa, Takeo Kageyama, Norihiro Iwai, Keishi Takaki
  • Publication number: 20110274131
    Abstract: Included are a plurality of surface-emitting laser elements each of which includes a substrate; a lower multilayer reflective mirror and an upper multilayer reflective mirror that are formed on the substrate and are formed from a periodic structure of a high-refractive index layer and a low-refractive index layer; an active layer provided between the lower multilayer reflective mirror and the upper multilayer reflective mirror; a lower contact layer positioned between the active layer and the lower multilayer reflective mirror, and is extended to an outer peripheral side of the upper multilayer reflective mirror; a lower electrode formed on a surface of a portion where the lower contact layer is extended; and an upper electrode for injecting a current to the active layer, wherein the surface-emitting laser elements are electrically connected in series to each other to form a series-connected element array.
    Type: Application
    Filed: January 20, 2010
    Publication date: November 10, 2011
    Applicant: FURUKAWA ELECTRIC CO., LTD.
    Inventors: Keishi Takaki, Hirotatsu Ishii, Hitoshi Shimizu, Norihiro Iwai
  • Publication number: 20110261852
    Abstract: A semiconductor laser element includes a first electrode, a second electrode, a first reflecting mirror, a second reflecting mirror, and a resonator. The resonator includes an active layer, a current confinement layer, a first semiconductor layer having a first doping concentration formed at a side opposite to the active layer across the current confinement layer, and a second semiconductor layer having a second doping concentration higher than the first doping concentration formed between the first semiconductor layer and the current confinement layer. The first electrode is provided to contact a part of a surface of the first semiconductor layer. The first semiconductor layer has a diffusion portion into which a component of the first electrode diffuses. The second semiconductor layer contacts the diffusion portion. The second semiconductor layer is positioned at a node of a standing wave at a time of laser oscillation of the semiconductor laser element.
    Type: Application
    Filed: December 10, 2009
    Publication date: October 27, 2011
    Applicant: FURUKAWA ELECTRIC CO., LTD
    Inventors: Suguru Imai, Keishi Takaki, Norihiro Iwai, Kinuka Tanabe, Hitoshi Shimizu, Hirotatsu Ishii
  • Publication number: 20110241564
    Abstract: A surface emitting laser is formed of a composition in which bandgap energy of layers from immediately above a current confinement layer to a second conductivity type contact layer is reduced towards the second conductivity type contact layer in a stacking direction, and a composition in which bandgap energy of layers from immediately below the current confinement layer to a first conductivity type contact layer is reduced towards the first conductivity type contact layer in a stacking direction while bypassing a quantum well layer or a quantum dot of an active layer, and includes a second conductivity type cladding layer including a material for reducing the mobility of carriers.
    Type: Application
    Filed: March 30, 2011
    Publication date: October 6, 2011
    Applicant: FURUKAWA ELECTRIC CO., LTD.
    Inventors: Hitoshi SHIMIZU, Takeo KAGEYAMA, Keishi TAKAKI, Norihiro IWAI
  • Patent number: 8031754
    Abstract: A surface emitting laser element that includes a cylindrical mesa post in which a plurality of semiconductor layers including an active layer is grown and that emits a laser light in a direction perpendicular to a substrate surface, the surface emitting laser element including a dielectric multilayer film on a top surface of the mesa post in at least a portion over a current injection area of the active layer; and a dielectric portion that includes layers fewer than layers of the dielectric multilayer film and that is arranged on a portion excluding the portion over the current injection area on the top surface of the mesa post and on at least part of a side surface of the mesa post.
    Type: Grant
    Filed: April 24, 2008
    Date of Patent: October 4, 2011
    Assignee: The Furukawa Electric Co., Ltd.
    Inventors: Norihiro Iwai, Takeo Kageyama, Kinuka Tanabe
  • Patent number: 7974327
    Abstract: A surface emitting laser element array comprises a plurality of surface emitting laser elements (15) on a same substrate (1) each comprising a mesa post formed of a laminated structure including an active layer (4) for reducing a crosstalk between the surface emitting laser elements constituting the surface emitting laser element array, and for improving a high speed response, wherein each of the surface emitting laser elements (15) comprises a first electrode (9), a second electrode (10) and a third electrode (11) that have a polarity different from that of the first electrode (9); the first electrode (9) is arranged on the mesa post; the second electrode (10) is arranged on one surface of the substrate (1) same as that of the first electrode (9); the third electrode (11) is arranged on the other surface of the substrate (1) opposite to that of the first electrode and the second electrode (9, 10) and is provided as a common electrode of the surface emitting laser elements (15); and an electric current is app
    Type: Grant
    Filed: September 1, 2006
    Date of Patent: July 5, 2011
    Assignee: Furukawa Electric Co., Ltd.
    Inventors: Maiko Ariga, Takeo Kageyama, Norihiro Iwai, Kazuaki Nishikata
  • Publication number: 20110076854
    Abstract: According to a method of manufacturing a vertical-cavity surface-emitting semiconductor laser element in accordance with the present invention, a process of wet etching is performed for a part that is oxidized in a layer of an AlGaAs (42) which configures a layer having an index of refraction as lower and in which a composition of aluminum is designed to be as higher comparing to the other pairs of layers in a DBR mirror at an upper side that are formed at an inner side of a mesa post (38). And then a process of filling up again is performed with making use of a layer of polyimide (26). Moreover, an etchant that includes such as a hydrofluoric acid or a buffered hydrofluoric acid or an aqueous ammonia or the like is made use in order to perform such the process of wet etching.
    Type: Application
    Filed: September 30, 2009
    Publication date: March 31, 2011
    Applicant: FURUKAWA ELECTRIC CO., LTD.
    Inventors: Kageyama Takeo, Norihiro Iwai, Koji Hiraiwa, Yoshihiko Ikenaga