Patents by Inventor Kazuhiro Harasaka

Kazuhiro Harasaka 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: 20240136793
    Abstract: A surface-emitting laser includes an active layer; multiple reflectors sandwiching the active layer; and an electrode pair connected to a power supply, through which a current is injected into the active layer. The surface-emitting laser emits at least one laser beam during a current injection period when the current injected into the active layer through the electrode pair during the current injection period is a first current and emits at least one laser beam during a current decrease period when the current injected into the active layer through the electrode pair during the current injection period is a second current exceeding the first current. The current decrease period is after the current injection period. The current injected into the active layer during the current decrease period is lower than the current injected into the active layer during the current injection period.
    Type: Application
    Filed: October 10, 2023
    Publication date: April 25, 2024
    Applicant: Ricoh Company, Ltd.
    Inventors: Naoto Jikutani, Kazuhiro Harasaka, Ryoichiro Suzuki, Yutaka Maita, Naofumi Ueno
  • Publication number: 20240128725
    Abstract: A surface-emitting laser array includes a substrate and a sub-arrays disposed on the substrate, the sub-arrays including a surface-emitting laser devices electrically connected to each other in parallel to emit light through the substrate, each of the surface-emitting laser devices having a light-emitting point and including a first semi-conducting layer of first conductivity. The laser array further includes a second semi-conducting layer of second conductivity, and a resonator disposed between the first semi-conducting layer and the second semi-conducting layer. The sub-arrays adjacent to each other include an electrode to electrically connect the first semi-conducting layer in the surface-emitting laser devices included in one of the sub-arrays and the second semi-conducting layer.
    Type: Application
    Filed: February 8, 2022
    Publication date: April 18, 2024
    Inventors: Kazuma IZUMIYA, Naoto JIKUTANI, Kazuhiro HARASAKA
  • Publication number: 20210167579
    Abstract: A surface emitting laser includes a first reflecting mirror; a second reflecting mirror; an active region between the first reflecting mirror and the second reflecting mirror. The first reflecting mirror and the second reflecting mirror each include a plurality of low refractive-index layers having a first refractive index; and a plurality of high refractive-index layers having a second refractive index higher than the first refractive index. The plurality of low refractive-index layers and the plurality of high refractive-index layers are alternated one after another. The plurality of high refractive-index layers of the first reflecting mirror includes a first layer; and a second layer having a higher thermal diffusion property in an in-plane direction than the first layer.
    Type: Application
    Filed: November 23, 2020
    Publication date: June 3, 2021
    Inventors: Kazuma IZUMIYA, Naoto JIKUTANI, Kazuhiro HARASAKA, Ryoichiro SUZUKI
  • Patent number: 9831633
    Abstract: A disclosed surface-emitting laser module includes a surface-emitting laser formed on a substrate to emit light perpendicular to its surface, a package including a recess portion in which the substrate having the surface-emitting laser is arranged, and a transparent substrate arranged to cover the recess portion of the package and the substrate having the surface-emitting laser such that the transparent substrate and the package are connected on a light emitting side of the surface-emitting laser. In the surface-emitting laser module, a high reflectance region and a low reflectance region are formed within a region enclosed by an electrode on an upper part of a mesa of the surface-emitting laser, and the transparent substrate is slanted to the surface of the substrate having the surface-emitting laser in a polarization direction of the light emitted from the surface-emitting laser determined by the high reflectance region and the low reflectance region.
    Type: Grant
    Filed: January 20, 2016
    Date of Patent: November 28, 2017
    Assignee: RICOH COMPANY, LTD.
    Inventors: Toshihiro Ishii, Satoru Sugawara, Yoshihiro Ohba, Kazuhiro Harasaka, Shunichi Sato, Kazuhiko Adachi
  • Publication number: 20160329903
    Abstract: An atomic oscillator includes a gas cell and a plurality of components. The plurality of components includes a temperature control device for the gas cell; an excitation light source that emits excitation light to excite atoms enclosed in the gas cell; a temperature control device for the excitation light source; and a light receiving element that detects the excitation light that passes through the gas cell. The plurality of components is mounted on an insulating film having wiring.
    Type: Application
    Filed: January 26, 2015
    Publication date: November 10, 2016
    Applicant: RICOH COMPANY, LTD
    Inventors: Kazuhiko ADACHI, Kazuhiro HARASAKA, Akihiro ITOH
  • Publication number: 20160149375
    Abstract: A disclosed surface-emitting laser module includes a surface-emitting laser formed on a substrate to emit light perpendicular to its surface, a package including a recess portion in which the substrate having the surface-emitting laser is arranged, and a transparent substrate arranged to cover the recess portion of the package and the substrate having the surface-emitting laser such that the transparent substrate and the package are connected on a light emitting side of the surface-emitting laser. In the surface-emitting laser module, a high reflectance region and a low reflectance region are formed within a region enclosed by an electrode on an upper part of a mesa of the surface-emitting laser, and the transparent substrate is slanted to the surface of the substrate having the surface-emitting laser in a polarization direction of the light emitted from the surface-emitting laser determined by the high reflectance region and the low reflectance region.
    Type: Application
    Filed: January 20, 2016
    Publication date: May 26, 2016
    Applicant: RICOH COMPANY, LTD.
    Inventors: Toshihiro ISHll, Satoru SUGAWARA, Yoshihiro OHBA, Kazuhiro HARASAKA, Shunichi SATO, Kazuhiko ADACHI
  • Patent number: 9276377
    Abstract: A disclosed surface-emitting laser module includes a surface-emitting laser formed on a substrate to emit light perpendicular to its surface, a package including a recess portion in which the substrate having the surface-emitting laser is arranged, and a transparent substrate arranged to cover the recess portion of the package and the substrate having the surface-emitting laser such that the transparent substrate and the package are connected on a light emitting side of the surface-emitting laser. In the surface-emitting laser module, a high reflectance region and a low reflectance region are formed within a region enclosed by an electrode on an upper part of a mesa of the surface-emitting laser, and the transparent substrate is slanted to the surface of the substrate having the surface-emitting laser in a polarization direction of the light emitted from the surface-emitting laser determined by the high reflectance region and the low reflectance region.
    Type: Grant
    Filed: October 8, 2014
    Date of Patent: March 1, 2016
    Assignee: RICOH COMPANY, LTD.
    Inventors: Toshihiro Ishii, Satoru Sugawara, Yoshihiro Ohba, Kazuhiro Harasaka, Shunichi Sato, Kazuhiko Adachi
  • Patent number: 9201404
    Abstract: An alkali metal cell is disclosed, including a substrate in which is formed an opening which penetrates from one face to the other face thereof; a first transparent substrate bonded to the other face of the substrate; and a second transparent substrate bonded to the one face of the substrate, wherein an alkali metal is sealed into a space surrounded by the first transparent substrate and the second transparent substrate in the opening of the substrate, wherein, in the substrate and the second transparent substrate, the space is enclosed by a bonding between a first bonding metal layer formed by a first bonding metal and a second bonding metal layer formed by a second bonding metal, and wherein the second bonding metal layer has a bonding temperature higher than that of the first bonding metal layer.
    Type: Grant
    Filed: November 18, 2013
    Date of Patent: December 1, 2015
    Assignee: RICOH COMPANY, LTD.
    Inventors: Kazuhiro Harasaka, Kazuhiko Adachi, Hiroyoshi Shouji, Akihiro Itoh, Shunichi Sato, Shinji Satoh
  • Patent number: 9176417
    Abstract: A surface-emitting laser device includes a transparent dielectric layer provided in an emitting region and configured to cause a reflectance at a peripheral part to be different from a reflectance at a central part in the emitting region. In the surface-emitting laser device, the thickness of a contact layer is different between a region having a relatively high reflectance and a region having a relatively low reflectance in the emitting region. The contact layer is provided on the high refractive index layer of an upper multilayer film reflecting mirror, and the total optical thickness of the high refractive index layer and the contact layer in the region having the relatively low reflectance is deviated from an odd number multiple of a one quarter oscillation wavelength of laser light emitted from the emitting region.
    Type: Grant
    Filed: April 4, 2014
    Date of Patent: November 3, 2015
    Assignee: RICOH COMPANY, LTD.
    Inventors: Kazuhiro Harasaka, Shunichi Sato, Masahiro Hayashi, Akihiro Itoh, Katsunari Hanaoka
  • Patent number: 9112518
    Abstract: A heater substrate for heating an alkali metal cell including an alkali metal includes a first heater wiring formed in a region surrounding an alkali metal encapsulating part in which the alkali metal is encapsulated; a second heater wiring formed in the region surrounding the alkali metal encapsulating part and inside the first heater wiring; and a third heater wiring formed outside the first heater wiring. A first electric current flowing in the first heater wiring is divided into a second electric current flowing in the second heater wiring and a third electric current flowing in the third heater wiring. A direction of the first electric current is opposite to a direction of the second electric current and a direction of the third electric current.
    Type: Grant
    Filed: August 6, 2014
    Date of Patent: August 18, 2015
    Assignee: RICOH COMPANY, LTD.
    Inventors: Kazuhiko Adachi, Kazuhiro Harasaka, Shunichi Sato
  • Patent number: 9046808
    Abstract: A surface emitting laser array includes a light emitting unit having a lower reflection mirror, a resonator structure including an active layer, and an upper reflection mirror laminated on a substrate; an electrode for the light emitting unit; a wiring member that establishes electrical connection between the light emitting unit and the electrode; and the substrate on which more than one of the light emitting units, the electrodes, and the wiring members are arranged. The light emitting unit has anisotropic internal stress, and the distance between the center of a first light emitting unit and the center line of the corresponding wiring member is arranged to be different from the distance between the center of a second light emitting unit and the center line of the corresponding wiring member so that variations in the polarization directions of the light emitting units may be within a predetermined range.
    Type: Grant
    Filed: December 21, 2012
    Date of Patent: June 2, 2015
    Assignee: RICOH COMPANY, LTD.
    Inventors: Kazuma Izumiya, Kazuhiro Harasaka
  • Publication number: 20150054591
    Abstract: A heater substrate for heating an alkali metal cell including an alkali metal includes a first heater wiring formed in a region surrounding an alkali metal encapsulating part in which the alkali metal is encapsulated; a second heater wiring formed in the region surrounding the alkali metal encapsulating part and inside the first heater wiring; and a third heater wiring formed outside the first heater wiring. A first electric current flowing in the first heater wiring is divided into a second electric current flowing in the second heater wiring and a third electric current flowing in the third heater wiring. A direction of the first electric current is opposite to a direction of the second electric current and a direction of the third electric current.
    Type: Application
    Filed: August 6, 2014
    Publication date: February 26, 2015
    Applicant: RICOH COMPANY, LTD.
    Inventors: Kazuhiko Adachi, Kazuhiro Harasaka, Shunichi Sato
  • Patent number: 8958449
    Abstract: A surface-emitting laser device configured to emit laser light in a direction perpendicular to a substrate includes a p-side electrode surrounding an emitting area on an emitting surface to emit the laser light; and a transparent dielectric film formed on an outside area outside a center part of the emitting area and within the emitting area to lower a reflectance to be less than that of the center part. The outside area within the emitting area has shape anisotropy in two mutually perpendicular directions.
    Type: Grant
    Filed: December 19, 2013
    Date of Patent: February 17, 2015
    Assignee: Ricoh Company, Ltd.
    Inventors: Kazuhiro Harasaka, Shunichi Sato, Naoto Jikutani
  • Publication number: 20150023381
    Abstract: A disclosed surface-emitting laser module includes a surface-emitting laser formed on a substrate to emit light perpendicular to its surface, a package including a recess portion in which the substrate having the surface-emitting laser is arranged, and a transparent substrate arranged to cover the recess portion of the package and the substrate having the surface-emitting laser such that the transparent substrate and the package are connected on a light emitting side of the surface-emitting laser. In the surface-emitting laser module, a high reflectance region and a low reflectance region are formed within a region enclosed by an electrode on an upper part of a mesa of the surface-emitting laser, and the transparent substrate is slanted to the surface of the substrate having the surface-emitting laser in a polarization direction of the light emitted from the surface-emitting laser determined by the high reflectance region and the low reflectance region.
    Type: Application
    Filed: October 8, 2014
    Publication date: January 22, 2015
    Applicant: RICOH COMPANY, LTD.
    Inventors: Toshihiro Ishii, Satoru Sugawara, Yoshihiro Ohba, Kazuhiro Harasaka, Shunichi Sato, Kazuhiko Adachi
  • Patent number: 8937982
    Abstract: A method of manufacturing a surface-emitting laser element having a light-emitting mesa structure with an emitting area including a high-reflectance portion and a low-reflectance portion includes forming a layered body that includes a lower reflecting mirror, a cavity structure, and an upper reflecting mirror on a substrate; forming a first area on an upper surface of the layered body; forming a second area having the same size as the first area on the upper surface of the layered body; forming a light-emitting mesa structure and a monitoring-mesa structure by etching the first area and the second area, respectively; forming a confinement structure including a current passage area surrounded by an oxide in the light-emitting mesa structure and the monitoring-mesa structure; and measuring the size of the current passage area of the monitoring-mesa structure.
    Type: Grant
    Filed: May 26, 2010
    Date of Patent: January 20, 2015
    Assignee: Ricoh Company, Ltd.
    Inventors: Yasuhiro Higashi, Kazuhiro Harasaka
  • Patent number: 8916418
    Abstract: A disclosed surface-emitting laser module includes a surface-emitting laser formed on a substrate to emit light perpendicular to its surface, a package including a recess portion in which the substrate having the surface-emitting laser is arranged, and a transparent substrate arranged to cover the recess portion of the package and the substrate having the surface-emitting laser such that the transparent substrate and the package are connected on a light emitting side of the surface-emitting laser. In the surface-emitting laser module, a high reflectance region and a low reflectance region are formed within a region enclosed by an electrode on an upper part of a mesa of the surface-emitting laser, and the transparent substrate is slanted to the surface of the substrate having the surface-emitting laser in a polarization direction of the light emitted from the surface-emitting laser determined by the high reflectance region and the low reflectance region.
    Type: Grant
    Filed: March 16, 2011
    Date of Patent: December 23, 2014
    Assignee: Ricoh Company, Ltd.
    Inventors: Toshihiro Ishii, Satoru Sugawara, Yoshihiro Ohba, Kazuhiro Harasaka, Shunichi Sato, Kazuhiko Adachi
  • Patent number: 8855159
    Abstract: A disclosed surface-emitting laser element includes a resonator structure having an active layer, a first semiconductor multilayer mirror and a second semiconductor multilayer mirror configured to sandwich the resonator structure having the active layer, an electrode provided around an emission region of a light-emitting surface, and a dielectric film provided in a peripheral portion within the emission region and outside a central portion of the emission region to make a reflectance of the peripheral portion lower than a reflectance of the central portion. In the surface-emitting laser element, an outer shape of a portion where the electrode provided around the emission region of the light-emitting surface is in contact with a contact layer includes corners.
    Type: Grant
    Filed: November 19, 2010
    Date of Patent: October 7, 2014
    Assignee: Ricoh Company, Ltd.
    Inventors: Shunichi Sato, Kazuhiro Harasaka, Naoto Jikutani
  • Patent number: 8809089
    Abstract: A disclosed method of manufacturing a surface emitting laser includes laminating a transparent dielectric layer on an upper surface of a laminated body; forming a first resist pattern on an upper surface of the dielectric layer, the first resist pattern including a pattern defining an outer perimeter of a mesa structure and a pattern protecting a region corresponding to one of the relatively high reflection rate part and the relatively low reflection rate part included in an emitting region; etching the dielectric layer by using the first resist pattern as an etching mask; and forming a second resist pattern protecting a region corresponding to an entire emitting region. These steps are performed before the mesa structure is formed.
    Type: Grant
    Filed: July 12, 2013
    Date of Patent: August 19, 2014
    Assignee: Ricoh Company, Ltd.
    Inventors: Hiroyoshi Shouji, Shunichi Sato, Akihiro Itoh, Kazuhiro Harasaka
  • Publication number: 20140219683
    Abstract: A surface-emitting laser device includes a transparent dielectric layer provided in an emitting region and configured to cause a reflectance at a peripheral part to be different from a reflectance at a central part in the emitting region. In the surface-emitting laser device, the thickness of a contact layer is different between a region having a relatively high reflectance and a region having a relatively low reflectance in the emitting region. The contact layer is provided on the high refractive index layer of an upper multilayer film reflecting mirror, and the total optical thickness of the high refractive index layer and the contact layer in the region having the relatively low reflectance is deviated from an odd number multiple of a one quarter oscillation wavelength of laser light emitted from the emitting region.
    Type: Application
    Filed: April 4, 2014
    Publication date: August 7, 2014
    Applicant: RICOH COMPANY, LTD.
    Inventors: Kazuhiro Harasaka, Shunichi Sato, Masahiro Hayashi, Akihiro Itoh, Katsunari Hanaoka
  • Patent number: 8774242
    Abstract: A surface emitting laser diode comprises a substrate, a lower reflector formed over the substrate, an active layer formed over the lower reflector, an upper reflector formed over the active layer, a current restrict structure including a current confinement region surrounded by insulation region. The current restrict structure is disposed in an upper reflector or between an active layer and the upper reflector, and an upper electrode formed over the upper reflector includes an aperture which corresponds to an emission region from which light is emitted in a first direction perpendicular to a surface of a substrate. The emission region and the current restrict structure including the current confinement region are selectively configured to obtain high single transverse mode, stabilized polarization direction, isotropic beam cross section and small divergence angle, while allowing the device to be manufactured with high yield rate.
    Type: Grant
    Filed: May 8, 2012
    Date of Patent: July 8, 2014
    Assignee: Ricoh Company, Ltd.
    Inventors: Akihiro Itoh, Kazuhiro Harasaka, Shunichi Sato, Naoto Jikutani