Patents by Inventor Hiroaki Furuichi

Hiroaki Furuichi 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: 6937628
    Abstract: A subject of the invention is to reduce the temperature dependence of an etalon as a wavelength locker for a semiconductor laser device and so forth. Concretely, it is to restrict the lowering of the wavelength locking performance of the etalon dependent on the temperature variation. A means to solve the subject is the use of an air gap etalon. Concretely, the means is provided with a media plate and parallel plane plates on both sides of the media plate. The two parallel plane plates and the space between them constitute the air gap etalon.
    Type: Grant
    Filed: March 5, 2002
    Date of Patent: August 30, 2005
    Assignee: Opnext Japan, Inc.
    Inventors: Kimio Tatsuno, Katsumi Kuroguchi, Atsuhiro Yamamoto, Teruhisa Azumaguchi, Hiroaki Furuichi
  • Patent number: 6912363
    Abstract: An optical module for use in detecting a plurality of different wavelengths by making use of the multiple wavelength selectivity of an etalon. The optical module includes a semiconductor laser, a lens for converting a beam emitted from the semiconductor laser into a substantially parallel beam, a beam splitter for splitting the converted beam into a reflected beam and a transmitted beam, and a light-receiving element disposed such that one of the split beams is incident thereupon through an etalon, wherein a center of the reflected beam from the etalon occurring as the beam is incident upon the etalon is arranged to return to a region other than a beam-emitting portion of the semiconductor laser.
    Type: Grant
    Filed: July 31, 2001
    Date of Patent: June 28, 2005
    Assignee: OpNext Japan, Inc.
    Inventors: Hiroaki Furuichi, Kazumi Kawamoto, Katsumi Kuroguchi, Atsuhiro Yamamoto, Keiichi Yamada, Tsutomu Okumura, Kazuo Takai, Shohei Hata
  • Patent number: 6826211
    Abstract: Conventionally, in the wavelength locking optical system, the wavelength as detected is deviated from a targeted range owing to the change of the peripheral temperature resulting from the temperature characteristics of the wavelength error detection device. To solve this prior issue, it is arranged such that a portion of the wavelength error detection device, through which portion light-beams passes, contacts a material of high heat conductivity.
    Type: Grant
    Filed: September 20, 2001
    Date of Patent: November 30, 2004
    Assignees: Hitachi, Ltd., Opnext Japan, Inc.
    Inventors: Kimio Tatsuno, Katsumi Kuroguchi, Hiroaki Furuichi, Atsuhiro Yamamoto, Norio Nakazato
  • Publication number: 20040228373
    Abstract: A laser diode module includes a laser diode device, a first photo detector part for receiving, first divided light that is a first portion of light when at least one of light emissions of the laser diode device is divided into two portions of light each traveling a different optical path, a second photo detector part for receiving second divided light that is a second portion of light thus divided via at least a wavelength selective member, and a controller which controls the lasing wavelength of the laser diode device on the basis of outputs of the first and second photo detector parts. A beam splitter provided between the laser diode and the wavelength selective member divides light emitted from the laser diode into the first and second divided light and a quarter-wave plate is provided in an optical path between the beam splitter and the wavelength selective member.
    Type: Application
    Filed: July 15, 2003
    Publication date: November 18, 2004
    Inventors: Kimio Tatsuno, Hiroaki Furuichi, Kazumi Kawamoto, Katsumi Kuroguchi
  • Patent number: 6813102
    Abstract: A PD (20) is mounted to a position offset (23) as viewed in the direction orthogonal to the center of an optical axis (14) of backward light (13) of an LD (11) in such a manner that a light receiving plane (21) thereof becomes substantially parallel to the center of the optical axis. Alternatively, the PD (20) is mounted thereto so that the light receiving plane of the PD is inclined at angles ranging from about 0° to about 30° to the center of the optical axis of the backward light. Further, the PD whose side face on the LD side is inclined, is used to repeatedly reflect the backward light between the PD and an LD mounting substrate, after which the backward light is launched on the light receiving plane 21.
    Type: Grant
    Filed: June 7, 2002
    Date of Patent: November 2, 2004
    Assignee: OpNext Japan, Inc.
    Inventors: Hiroaki Furuichi, Kazumi Kawamoto, Naoki Matsushima
  • Publication number: 20040208211
    Abstract: A ceramic substrate is provided through a stem of a can-package, the desired number of wirings including the high speed signal wirings are formed on this ceramic substrate and the necessary electronic components other than a light-emitting/photosensitive element such as driver LSI and amplifying LSI or the like are also accommodated within the can-package.
    Type: Application
    Filed: August 15, 2002
    Publication date: October 21, 2004
    Applicant: OpNext Japan, Inc.
    Inventors: Shigenobu Maruyama, Kazumi Kawamoto, Hiroaki Furuichi, Tooru Yoshida, Isamu Yoshida, Katsuya Oono, Osamu Yamada, Hiroshi Ibe, Shigeru Tokita, Tarou Tonoduka, Yasunori Iwafuji, Katsumi Kuroguchi
  • Patent number: 6805496
    Abstract: The incident angle of the beam with regard to an etalon is arranged finely tunable by either rotating the etalon provided with a plane of incidence inclined with regard to the rotational axis thereof in the vicinity of the optical axis or rotating a lens whose edge surface is obliquely ground around the optical axis, which allows the incident angle of the laser beam with regard to the etalon to be adjusted and fixed with high precision.
    Type: Grant
    Filed: January 17, 2002
    Date of Patent: October 19, 2004
    Assignee: OpNext Japan, Inc.
    Inventors: Hiroaki Furuichi, Kazumi Kawamoto, Katsumi Kuroguchi, Keiichi Yamada, Shintarou Sakamoto
  • Publication number: 20040197949
    Abstract: In anodic bonding between a conductor or semiconductor and glass, in order to attain good adhesion at a lower bonding temperature than usual and improve the toughness at its boundary to obtain higher reliability for a bonded portion even in a case where bonded members are warped or dust is present at the bonding boundary, a soft metal film is formed on the surface of a conductor or semiconductor on which an active metal film having high reactivity with oxygen is formed, whereby a warp or dust, if any, can be absorbed by the deformation of the soft metal film, thereby to improve the adhesion at the boundary. Adhesion at the bonding boundary is improved even at a low bonding temperature of, e.g., about 200° C. Further, the toughness at the bonding boundary can be improved to increase reliability by roughening the bonded surface on the side of the glass.
    Type: Application
    Filed: February 26, 2004
    Publication date: October 7, 2004
    Inventors: Shohei Hata, Hideo Sotokawa, Hiroaki Furuichi
  • Publication number: 20040114883
    Abstract: The present invention provides an optical transmission module comprising: a laser diode; a lens for condensing a laser beam from the laser diode; a fiber ferrule which is placed so that the laser beam condensed by the lens can enter a fiber core; and a lens aperture or a lens aperture portion which is provided at one of the lens itself, a position before the lens and a position after the lens.
    Type: Application
    Filed: July 30, 2003
    Publication date: June 17, 2004
    Applicant: OPNEXT JAPAN, INC.
    Inventors: Hiroaki Furuichi, Hiroyasu Sasaki, Kazumi Kawamoto
  • Patent number: 6632023
    Abstract: An adapter 5 for an optical connector comprises a pair of wall portions 55a and 55b on a mounting surface 56a. The structure allows the adapter to accommodate an optical connector 4 inserted from a direction vertical to the mounting surface 56a, and allows the adapter to accommodate an optical connector 7 inserted along a predetermined axis 8. On this account, it is possible to insert the connector 7 along the predetermined axis 8 to the housed optical connector 4. Since the optical connector 4 is mated to and demated from the optical connector 7 in this sort of adapters, force applied to an optical module 2 is decreased in mating/demating the connector. An optical module product 9 includes the optical module 2, a coated optical fiber 3, the optical connector 4, and the optical connector's adapter 5. An optical module mounting substrate product 1 includes the optical module product 9 and a substrate 10 for mounting thereon the optical module 2 and the adapter 5 for optical connectors.
    Type: Grant
    Filed: May 16, 2001
    Date of Patent: October 14, 2003
    Assignees: Sumitomo Electric Industries, Ltd., Hitachi, Ltd.
    Inventors: Shinji Ogawa, Hidetoshi Ishida, Toshiaki Kakii, Atsushi Takai, Atsushi Miura, Hiroaki Furuichi
  • Publication number: 20030189770
    Abstract: A PD (20) is mounted to a position offset (23) as viewed in the direction orthogonal to the center of an optical axis (14) of backward light (13) of an LD (11) in such a manner that a light receiving plane (21) thereof becomes substantially parallel to the center of the optical axis. Alternatively, the PD (20) is mounted thereto so that the light receiving plane of the PD is inclined at angles ranging from about 0° to about 30° to the center of the optical axis of the backward light. Further, the PD whose side face on the LD side is inclined, is used to repeatedly reflect the backward light between the PD and an LD mounting substrate, after which the backward light is launched on the light receiving plane 21.
    Type: Application
    Filed: June 7, 2002
    Publication date: October 9, 2003
    Applicants: OpNext Japan, Inc., Hitachi, Ltd.
    Inventors: Hiroaki Furuichi, Kazumi Kawamoto, Naoki Matsushima
  • Patent number: 6597712
    Abstract: In a wavelength locking optical system, a resonator is formed between a wavelength deviation detection device and a facet of the laser diode, which makes a control signal unstable. A solution to this problem is to arrange polarization controlling elements between a wavelength deviation detection filter and a laser diode to stabilize the deviation signal, and to perform wavelength-locking with the stabilizer signal.
    Type: Grant
    Filed: August 23, 2001
    Date of Patent: July 22, 2003
    Assignee: Hitachi, Ltd.
    Inventors: Kimio Tatsuno, Hiroaki Furuichi, Kazumi Kawamoto, Katsumi Kuroguchi
  • Publication number: 20030076564
    Abstract: An optical module for use in detecting a plurality of different wavelengths by making use of the multiple wavelength selectivity of an etalon. The optical module includes a semiconductor laser, a lens for converting a beam emitted from the semiconductor laser into a substantially parallel beam, a beam splitter for splitting the converted beam into a reflected beam and a transmitted beam, and a light-receiving element disposed such that one of the split beams is incident thereupon through an etalon, wherein a center of the reflected beam from the etalon occurring as the beam is incident upon the etalon is arranged to return to a region other than a beam-emitting portion of the semiconductor laser.
    Type: Application
    Filed: July 31, 2001
    Publication date: April 24, 2003
    Inventors: Hiroaki Furuichi, Kazumi Kawamoto, Katsumi Kuroguchi, Atsuhiro Yamamoto, Keiichi Yamada, Tsutomu Okumura, Kazuo Takai, Shohei Hata
  • Publication number: 20030072542
    Abstract: The incident angle of the beam with regard to an etalon is arranged finely tunable by either rotating the etalon provided with a plane of incidence inclined with regard to the rotational axis thereof in the vicinity of the optical axis or rotating a lens whose edge surface is obliquely ground around the optical axis, which allows the incident angle of the laser beam with regard to the etalon to be adjusted and fixed with high precision.
    Type: Application
    Filed: January 17, 2002
    Publication date: April 17, 2003
    Applicant: OpNext Japan, Inc.
    Inventors: Hiroaki Furuichi, Kazumi Kawamoto, Katsumi Kuroguchi, Keiichi Yamada, Shintarou Sakamoto
  • Publication number: 20030067948
    Abstract: A subject of the invention is to reduce the temperature dependence of an etalon as a wavelength locker for a semiconductor laser device and so forth. Concretely, it is to restrict the lowering of the wavelength locking performance of the etalon dependent on the temperature variation. A means to solve the subject is the use of an air gap etalon. Concretely, the means is provided with a media plate and parallel plane plates on both sides of the media plate. The two parallel plane plates and the space between them constitute the air gap etalon.
    Type: Application
    Filed: March 5, 2002
    Publication date: April 10, 2003
    Inventors: Kimio Tatsuno, Katsumi Kuroguchi, Atsuhiro Yamamoto, Teruhisa Azumaguchi, Hiroaki Furuichi
  • Publication number: 20030039276
    Abstract: The problem of the disclosed technology is that, in a wavelength locking optical system, a resonator is formed between a wavelength deviation detection device and a facet of a laser diode, which makes a control signal unstable.
    Type: Application
    Filed: August 23, 2001
    Publication date: February 27, 2003
    Inventors: Kimio Tatsuno, Hiroaki Furuichi, Kazumi Kawamoto, Katsumi Kuroguchi
  • Publication number: 20030002050
    Abstract: Conventionally, in the wavelength locking optical system, the wavelength as detected is deviated from a targeted range owing to the change of the peripheral temperature resulting from the temperature characteristics of the wavelength error detection device. To solve this prior issue, it is arranged such that a portion of the wavelength error detection device, through which portion light-beams passes, contacts a material of high heat conductivity.
    Type: Application
    Filed: September 20, 2001
    Publication date: January 2, 2003
    Inventors: Kimio Tatsuno, Katsumi Kuroguchi, Hiroaki Furuichi, Atsuhiro Yamamoto, Norio Nakazato
  • Patent number: 6501891
    Abstract: An optical transmission module includes at least one of a light emitting element and a light receiving element, an optical fiber and an optical wave-guide provided between the light emitting element or the light receiving element and the optical fiber. The optical wave-guide has a z-axis in a direction of light propagation, an x-axis in a vertical direction on a cross-sectional plane perpendicular to the z-axis, and a y-axis in horizontal direction thereon. The optical wave-guide includes a core portion formed so that light is transmitted in the direction of the z axis, around at a center of an origin of the x axis and y axis, and a crud layer which surrounds the core portion and is lower in refractive index than a refractive index of the core portion. The core portion includes a plural number of segments, and at least one of the segments has a recess portion.
    Type: Grant
    Filed: July 25, 2001
    Date of Patent: December 31, 2002
    Assignee: Hitachi, Ltd.
    Inventors: Kazumi Kawamoto, Hiroaki Furuichi
  • Publication number: 20010055450
    Abstract: An optical transmission module includes at least one of a light emitting element and a light receiving element, an optical fiber and an optical wave-guide provided between the light emitting element or the light receiving element and the optical fiber. The optical wave-guide has a z-axis in a direction of light propagation, an x-axis in a vertical direction on a cross-sectional plane perpendicular to the z-axis, and a y-axis in horizontal direction thereon. The optical wave-guide includes a core portion formed so that light is transmitted in the direction of the z axis, around at a center of an origin of the x axis and y axis, and a crud layer which surrounds the core portion and is lower in refractive index than a refractive index of the core portion. The core portion includes a plural number of segments, and at least one of the segments has a recess portion.
    Type: Application
    Filed: July 25, 2001
    Publication date: December 27, 2001
    Inventors: Kazumi Kawamoto, Hiroaki Furuichi
  • Patent number: 6289157
    Abstract: Utilizing propagation of light along with a region of high refractive index, an enlargement and a reduction of an optical beam-spot are achieved by a plurality of layers of the cruds, in which relationships in magnitude of the refractive index are defined with respect to a segment-like core.
    Type: Grant
    Filed: January 27, 2000
    Date of Patent: September 11, 2001
    Assignee: Hitachi, Ltd.
    Inventors: Kazumi Kawamoto, Hiroaki Furuichi