Patents by Inventor Kei Emoto

Kei Emoto 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: 11837850
    Abstract: A method for manufacturing a GaN-based surface-emitting laser by an MOVPE includes: (a) growing a first cladding layer with a {0001} growth plane; (b) growing a guide layer on the first cladding layer; (c) forming holes in a surface of the guide layer by etching, the holes being two-dimensionally periodically arranged within a plane parallel to the guide layer; (d) etching the guide layer by using an etchant having selectivity to the {0001} plane and a {10?10} plane of the guide layer; (e) supplying a gas containing a nitrogen source to cause mass transport without supplying a group-III material gas, and then supplying the group-III material gas for growth, whereby a first embedding layer closing openings of the holes is formed to form a photonic crystal layer; and (f) growing an active layer and a second cladding layer in this order on the first embedding layer.
    Type: Grant
    Filed: December 16, 2020
    Date of Patent: December 5, 2023
    Assignees: KYOTO UNIVERSITY, STANLEY ELECTRIC CO., LTD.
    Inventors: Susumu Noda, Tomoaki Koizumi, Kei Emoto
  • Publication number: 20230387659
    Abstract: A method of manufacturing a surface-emitting laser, includes (a) forming a first semiconductor layer including a photonic-crystal (PC) layer, (b) growing, on the first semiconductor layer, an active layer and a second semiconductor layer, (c) performing spectrometry in which a thickness from a surface of the second semiconductor layer to a position where the spectrometry light is reflected by the PC layer is measured, (d) forming a translucent electrode having a thickness calculated based on an optical path length corresponding to the thickness obtained by the spectrometry on the second semiconductor layer, and (e) forming a reflection layer on the translucent electrode, in which the layer thickness of the translucent electrode is determined such that a light intensity of interference light of (i) direct diffracted light radiated from the PC layer and (ii) reflected diffracted light radiated from the PC layer and reflected by the reflection layer is larger than a light intensity of the direct diffracted light
    Type: Application
    Filed: May 12, 2023
    Publication date: November 30, 2023
    Applicants: KYOTO UNIVERSITY, STANLEY ELECTRIC CO., LTD.
    Inventors: Susumu NODA, Kei EMOTO, Tomoaki KOIZUMI, Hiroshi KOTANI
  • Publication number: 20230283049
    Abstract: A method for manufacturing a GaN-based surface-emitting laser by an MOVPE includes: growing a first cladding layer with a {0001} growth plane; growing a guide layer on the first cladding layer; forming holes which are two-dimensionally periodically arranged within the guide layer; etching the guide layer by ICP-RIE using a chlorine-based gas and an argon; supplying a gas containing a nitrogen to cause mass-transport, and then supplying the group-III gas for growth, whereby a first embedding layer closing openings of the holes is formed to form a photonic crystal layer; and growing an active layer and a second cladding layer on the first embedding layer, The step includes a step of referring to already-obtained data on a relationship of an attraction voltage and a ratio of gases in the ICP-RIE with a diameter distribution of air holes embedded, and applying the attraction voltage and the ratio to the ICP-RIE.
    Type: Application
    Filed: April 21, 2023
    Publication date: September 7, 2023
    Applicants: Kyoto University, Stanley Electric Co., Ltd.
    Inventors: Susumu NODA, Tomoaki KOIZUMI, Kei EMOTO
  • Publication number: 20230275398
    Abstract: A photonic-crystal surface-emitting laser element includes: a first semiconductor layer formed by embedding a photonic crystal layer that includes air holes arranged with two-dimensional periodicity in a formation region in a plane parallel to the photonic crystal layer; an active layer formed on the first semiconductor layer; a second semiconductor layer formed on the active layer; and a mesa portion with a mesa shape formed at a surface of the second semiconductor layer, wherein the mesa portion is located inside the formation region of the air holes when viewed in a direction perpendicular to the photonic crystal layer.
    Type: Application
    Filed: July 1, 2021
    Publication date: August 31, 2023
    Applicants: KYOTO UNIVERSITY, STANLEY ELECTRIC CO., LTD.
    Inventors: Susumu NODA, Takuya INOUE, Kei EMOTO, Tomoaki KOIZUMI
  • Patent number: 11670910
    Abstract: A method for manufacturing a GaN-based surface-emitting laser by an MOVPE includes: (a) growing a first cladding layer with a {0001} growth plane; (b) growing a guide layer on the first cladding layer; (c) forming holes which are two-dimensionally periodically arranged within the guide layer; (d) etching the guide layer by ICP-RIE using a chlorine-based gas and an argon; (e) supplying a gas containing a nitrogen to cause mass-transport, and then supplying the group-III gas for growth, whereby a first embedding layer closing openings of the holes is formed to form a photonic crystal layer; and (f) growing an active layer and a second cladding layer on the first embedding layer, The step (d) includes a step of referring to already-obtained data on a relationship of an attraction voltage and a ratio of gases in the ICP-RIE with a diameter distribution of air holes embedded, and applying the attraction voltage and the ratio to the ICP-RIE.
    Type: Grant
    Filed: December 16, 2020
    Date of Patent: June 6, 2023
    Assignees: KYOTO UNIVERSITY, STANLEY ELECTRIC CO., LTD.
    Inventors: Susumu Noda, Tomoaki Koizumi, Kei Emoto
  • Publication number: 20230127863
    Abstract: A surface-emitting laser element includes: a first guide layer including a photonic crystal layer that is formed on a c plane of a group-3 nitride semiconductor and includes air holes arranged with two-dimensional periodicity in a plane parallel to the photonic crystal layer, and an embedding layer that is formed on the photonic crystal layer and closes the air holes; an active layer formed on the first guide layer; and a second guide layer formed on the active layer, wherein an air hole set including at least a main air hole and a sub-air hole smaller in size than the main air hole is arranged at each square lattice point in the plane parallel to the photonic crystal layer, and wherein the main air hole has a regular-hexagonal prism shape, a long-hexagonal prism shape, or an elliptic cylindrical shape with a major axis parallel to a <11-20> axis.
    Type: Application
    Filed: February 10, 2021
    Publication date: April 27, 2023
    Applicants: KYOTO UNIVERSITY, STANLEY ELECTRIC CO., LTD.
    Inventors: Susumu NODA, Takuya INOUE, Tomoaki KOIZUMI, Kei EMOTO
  • Patent number: 11539187
    Abstract: A surface emission laser formed of a group III nitride semiconductor includes a first conductivity type first clad layer; a first conductivity type first guide layer on the first clad layer; a light-emitting layer on the first guide layer; a second guide layer on the light-emitting layer; and a second conductivity type second clad layer on the second guide layer. The first or second guide layer internally includes voids periodically arranged at square lattice positions with two axes perpendicular to one another as arrangement directions in a surface parallel to the guide layer. The voids have a polygonal prism structure or an oval columnar structure with a long axis and a short axis perpendicular to the long axis in the parallel surface, and the long axis is inclined with respect to one axis among the arrangement directions of the voids.
    Type: Grant
    Filed: December 17, 2018
    Date of Patent: December 27, 2022
    Assignees: KYOTO UNIVERSITY, STANLEY ELECTRIC CO., LTD.
    Inventors: Susumu Noda, Yoshinori Tanaka, Menaka De Zoysa, Tomoaki Koizumi, Kei Emoto
  • Patent number: 11283243
    Abstract: A method for manufacturing a surface emitting laser made of a group-III nitride semiconductor by an MOVPE method includes: (a) growing a first cladding layer of a first conductive type on a substrate; (b) growing a first optical guide layer of the first conductive type on the first cladding layer; (c) forming holes having a two-dimensional periodicity in a plane parallel to the first optical guide layer, in the first optical guide layer by etching; (d) supplying a gas containing a group-III material and a nitrogen source and performing growth to form recessed portions having a facet of a predetermined plane direction above openings of the holes, thereby closing the openings of the holes; and (e) planarizing the recessed portions by mass transport, after the openings of the holes have been closed, wherein after the planarizing at least one side surface of the holes is a {10-10} facet.
    Type: Grant
    Filed: February 27, 2018
    Date of Patent: March 22, 2022
    Assignees: KYOTO UNIVERSITY, STANLEY ELECTRIC CO., LTD.
    Inventors: Susumu Noda, Yoshinori Tanaka, Menaka De Zoysa, Junichi Sonoda, Tomoaki Koizumi, Kei Emoto
  • Publication number: 20210328406
    Abstract: A surface emitting laser element formed of a group III nitride semiconductor, comprising: a first clad layer of a first conductivity type; a first guide layer of the first conductivity type having a photonic crystal layer formed on the first clad layer including voids disposed having two-dimensional periodicity in a surface parallel to the layer and a first embedding layer formed on the photonic crystal layer; a second embedding layer formed on the first embedding layer by crystal growth; an active layer formed on the second embedding layer; a second guide layer formed on the active layer; and a second clad layer of a second conductivity type formed on the second guide layer, the second conductivity type being a conductivity type opposite to the first conductivity type. The first embedding layer has a surface including pits disposed at surface positions corresponding to the voids.
    Type: Application
    Filed: August 29, 2019
    Publication date: October 21, 2021
    Applicants: KYOTO UNIVERSITY, STANLEY ELECTRIC CO., LTD.
    Inventors: Susumu NODA, Yoshinori TANAKA, Menaka DE ZOYSA, Kenji ISHIZAKI, Tomoaki KOIZUMI, Kei EMOTO
  • Publication number: 20210184431
    Abstract: A method for manufacturing a GaN-based surface-emitting laser by an MOVPE includes: (a) growing a first cladding layer with a {0001} growth plane; (b) growing a guide layer on the first cladding layer; (c) forming holes which are two-dimensionally periodically arranged within the guide layer; (d) etching the guide layer by ICP-RIE using a chlorine-based gas and an argon; (e) supplying a gas containing a nitrogen to cause mass-transport, and then supplying the group-III gas for growth, whereby a first embedding layer closing openings of the holes is formed to form a photonic crystal layer; and (f) growing an active layer and a second cladding layer on the first embedding layer, The step (d) includes a step of referring to already-obtained data on a relationship of an attraction voltage and a ratio of gases in the ICP-RIE with a diameter distribution of air holes embedded, and applying the attraction voltage and the ratio to the ICP-RIE.
    Type: Application
    Filed: December 16, 2020
    Publication date: June 17, 2021
    Applicants: Kyoto University, Stanley Electric Co., Ltd.
    Inventors: Susumu NODA, Tomoaki KOIZUMI, Kei EMOTO
  • Publication number: 20210184430
    Abstract: A method for manufacturing a GaN-based surface-emitting laser by an MOVPE includes: (a) growing a first cladding layer with a {0001} growth plane; (b) growing a guide layer on the first cladding layer; (c) forming holes in a surface of the guide layer by etching, the holes being two-dimensionally periodically arranged within a plane parallel to the guide layer; (d) etching the guide layer by using an etchant having selectivity to the {0001} plane and a {10-10} plane of the guide layer; (e) supplying a gas containing a nitrogen source to cause mass transport without supplying a group-III material gas, and then supplying the group-III material gas for growth, whereby a first embedding layer closing openings of the holes is formed to form a photonic crystal layer; and (f) growing an active layer and a second cladding layer in this order on the first embedding layer.
    Type: Application
    Filed: December 16, 2020
    Publication date: June 17, 2021
    Applicants: Kyoto University, Stanley Electric Co., Ltd.
    Inventors: Susumu NODA, Tomoaki KOIZUMI, Kei EMOTO
  • Publication number: 20210013700
    Abstract: A surface emission laser formed of a group III nitride semiconductor includes a first conductivity type first clad layer; a first conductivity type first guide layer on the first clad layer; a light-emitting layer on the first guide layer; a second guide layer on the light-emitting layer; and a second conductivity type second clad layer on the second guide layer. The first or second guide layer internally includes voids periodically arranged at square lattice positions with two axes perpendicular to one another as arrangement directions in a surface parallel to the guide layer. The voids have a polygonal prism structure or an oval columnar structure with a long axis and a short axis perpendicular to the long axis in the parallel surface, and the long axis is inclined with respect to one axis among the arrangement directions of the voids.
    Type: Application
    Filed: December 17, 2018
    Publication date: January 14, 2021
    Applicants: Kyoto University, Stanley Electric Co., Ltd.
    Inventors: Susumu NODA, Yoshinori TANAKA, Menaka DE ZOYSA, Tomoaki KOIZUMI, Kei EMOTO
  • Publication number: 20200251887
    Abstract: A method for manufacturing a surface emitting laser made of a group-III nitride semiconductor by an MOVPE method includes: (a) of growing a first cladding layer of a first conductive type on a substrate; (b) of growing a first optical guide layer of the first conductive type on the first cladding layer; (c) of forming holes having a two-dimensional periodicity in a plane parallel to the first optical guide layer, in the first optical guide layer by etching; (d) supplying a gas containing a group-III material and a nitrogen source and performing growth to form recessed portions having a facet of a predetermined plane direction above openings of the holes, thereby closing the openings of the holes; and (e) of planarizing the recessed portions by mass transport, after the openings of the holes have been closed, wherein after said the planarizing, at least one side surface of the holes is a {10-10} facet.
    Type: Application
    Filed: February 27, 2018
    Publication date: August 6, 2020
    Applicants: KYOTO UNIVERSITY, STANLEY ELECTRIC CO., LTD.
    Inventors: Susumu NODA, Yoshinori TANAKA, Menaka DE ZOYSA, Junichi SONODA, Tomoaki KOIZUMI, Kei EMOTO
  • Patent number: 9214330
    Abstract: A light source device comprising a filament showing high electric power-to-visible light conversion efficiency is provided. The light source device of the present invention comprises a translucent gastight container, a filament disposed in the translucent gastight container, and a lead wire for supplying an electric current to the filament. The filament comprises a substrate formed from a metal material and a visible light-absorbing film covering the substrate. The visible light-absorbing film is transparent to lights of infrared region. The reflectance of the substrate for visible lights is thereby made low, and the reflectance of the substrate for infrared lights is thereby made high. Therefore, radiation of infrared lights is suppressed, and visible luminous efficiency can be enhanced.
    Type: Grant
    Filed: December 20, 2012
    Date of Patent: December 15, 2015
    Assignee: STANLEY ELECTRIC CO., LTD.
    Inventors: Yasuyuki Kawakami, Takahiro Matsumoto, Takao Saito, Kei Emoto
  • Publication number: 20140346944
    Abstract: A light source device comprising a filament showing high electric power-to-visible light conversion efficiency is provided. The light source device of the present invention comprises a translucent gastight container, a filament disposed in the translucent gastight container, and a lead wire for supplying an electric current to the filament. The filament comprises a substrate formed from a metal material and a visible light-absorbing film covering the substrate. The visible light-absorbing film is transparent to lights of infrared region. The reflectance of the substrate for visible lights is thereby made low, and the reflectance of the substrate for infrared lights is thereby made high. Therefore, radiation of infrared lights is suppressed, and visible luminous efficiency can be enhanced.
    Type: Application
    Filed: December 20, 2012
    Publication date: November 27, 2014
    Applicant: STANLEY ELECTRIC CO., LTD
    Inventors: Yasuyuki Kawakami, Takahiro Matsumoto, Takao Saito, Kei Emoto