Patents by Inventor Shunichi Sato

Shunichi Sato 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: 20130335155
    Abstract: A disclosed surface-emitting laser element includes a lower DBR formed on a substrate, an active layer formed on the lower DBR, an upper DBR formed on the active layer, a wavelength-adjusting layer formed above the active layer, and a plurality of surface-emitting lasers configured to emit respective laser beams having different wavelengths by changing a thickness of the wavelength-adjusting layer. In the surface-emitting laser element, the wavelength-adjusting layer includes one of a first film having alternately layered GaInP and GaAsP and a second film having alternately layered GaInP and GaAs, the thickness of the wavelength-adjusting layer being changed by partially removing each of the alternating layers of a corresponding one of the first and second films.
    Type: Application
    Filed: March 14, 2012
    Publication date: December 19, 2013
    Applicant: RICOH COMPANY LTD
    Inventor: Shunichi Sato
  • Patent number: 8609447
    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: March 15, 2010
    Date of Patent: December 17, 2013
    Assignee: Ricoh Company, Ltd.
    Inventors: Hiroyoshi Shouji, Shunichi Sato, Akihiro Itoh, Kazuhiro Harasaka
  • Patent number: 8594146
    Abstract: A surface emitting laser element is disclosed. The surface emitting laser element includes a resonator structural body including an active layer, first and second semiconductor distributed Bragg reflectors which sandwich the resonator structural body, and a confinement structure which can confine an injection current and a lateral mode of oscillation light at the same time by being formed with selective oxidation of a layer to be selectively oxidized containing aluminum in the first semiconductor distributed Bragg reflector. A thickness of the layer to be selectively oxidized is 28 nm, and a temperature when an oscillation threshold current becomes a minimum value is approximately 17° C.
    Type: Grant
    Filed: February 9, 2009
    Date of Patent: November 26, 2013
    Assignee: Ricoh Company, Ltd.
    Inventors: Naoto Jikutani, Satoru Sugawara, Shunichi Sato
  • Publication number: 20130286150
    Abstract: A surface-emission laser array comprises a plurality of surface-emission laser diode elements arranged in the form of a two-dimensional array, wherein a plurality of straight lines drawn perpendicularly to a straight line extending in a first direction from respective centers of the plurality of surface emission laser diode elements aligned in a second direction perpendicular to the first direction, are formed with generally equal interval in the first direction, the plurality of surface-emission laser diode elements are aligned in the first direction with an interval set to a reference value, and wherein the number of the surface-emission laser diode elements aligned in the first direction is smaller than the number of the surface-emission laser diode elements aligned in the second direction.
    Type: Application
    Filed: June 28, 2013
    Publication date: October 31, 2013
    Applicant: RICOH COMPANY, LTD.
    Inventors: Shunichi SATO, Akihiro ITOH, Hiroyoshi SHOUJI, Yoshinori HAYASHI, Daisuke ICHII, Kei HARA, Mitsumi FUJII
  • Publication number: 20130273677
    Abstract: A disclosed surface emitting laser device includes a light emitting section having a mesa structure where a lower reflection mirror, an oscillation structure, and an upper reflection mirror are laminated on a substrate, the oscillation structure including an active layer, the upper reflection mirror including a current confined structure where an oxide surrounds a current passage region, a first dielectric film that coats the entire surface of an emitting region of the light emitting section, the transparent dielectric including a part where the refractive index is relatively high and a part where the refractive index is relatively low, and a second dielectric film that coats a peripheral part on the upper surface of the mesa structure. Further, the dielectric film includes a lower dielectric film and an upper dielectric film, and the lower dielectric film is coated with the upper dielectric film.
    Type: Application
    Filed: June 12, 2013
    Publication date: October 17, 2013
    Applicant: RICOH COMPANY, LTD.
    Inventors: Hiroyoshi Shouji, Shunichi Sato
  • Publication number: 20130243022
    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: Application
    Filed: May 6, 2013
    Publication date: September 19, 2013
    Applicant: RICOH COMPANY, LTD.
    Inventors: Kazuhiro Harasaka, Shunichi Sato, Naoto Jikutani
  • Patent number: 8537870
    Abstract: A laser diode includes a substrate having a lattice constant of GaAs or between GaAs and GaP, a first cladding layer of AlGaInP formed on the substrate, an active layer of GaInAsP formed on the first cladding layer, an etching stopper layer of GaInP formed on the active layer, a pair of current-blocking regions of AlGaInP formed on the etching stopper layer so as to define a strip region therebetween, an optical waveguide layer of AlGaInP formed on the pair of current-blocking regions so as to cover the etching stopper layer in the stripe region, and a second cladding layer of AlGaInP formed on the optical waveguide layer, wherein the current-blocking regions having an Al content substantially identical with an Al content of the second cladding layer.
    Type: Grant
    Filed: July 21, 2011
    Date of Patent: September 17, 2013
    Assignee: Ricoh Company, Limited
    Inventors: Naoto Jikutani, Shunichi Sato
  • Publication number: 20130230070
    Abstract: A surface-emitting laser array includes a plurality of surface-emitting laser elements. Each surface-emitting laser element includes a first reflection layer formed on a substrate, a resonator formed in contact with the first reflection layer and containing an active layer, and a second reflection layer formed over the first reflection layer and in contact with the resonator. The second reflection layer contains a selective oxidation layer. The first reflection layer contains on the active layer side at least a low refractive index layer having an oxidation rate equivalent to or larger than an oxidation rate of a selective oxidation layer contained in the second reflection layer. The resonator is made of an AlGaInPAs base material containing at least In. A bottom of a mesa structure is located under the selective oxidation layer and over the first reflection layer.
    Type: Application
    Filed: April 19, 2013
    Publication date: September 5, 2013
    Applicant: RICOH COMPANY, LTD.
    Inventors: Shunichi Sato, Akihiro Itoh, Satoru Sugawara, Hiroyoshi Shouji
  • Patent number: 8508567
    Abstract: A surface-emission laser array comprises a plurality of surface-emission laser diode elements arranged in the form of a two-dimensional array including a plurality of columns of the surface-emission laser diode elements, each column including therein at least two surface-emission laser diode elements in a first direction. The surface-emission laser diode elements in a column are disposed with an equal interval in the first direction. The plural columns arc disposed in a second direction which is perpendicular to the first direction. An interval between two adjacent columns is larger in a central part than in a peripheral part of the two-dimensional array of the surface-emission laser diode elements in the second direction.
    Type: Grant
    Filed: November 28, 2011
    Date of Patent: August 13, 2013
    Assignee: Ricoh Company, Ltd.
    Inventors: Shunichi Sato, Akihiro Itoh, Hiroyoshi Shouji, Yoshinori Hayashi, Daisuke Ichii, Kei Hara, Mitsumi Fujii
  • Patent number: 8502852
    Abstract: A surface emitting laser device includes a substrate and plural semiconductor layers laminated on the substrate, the plural semiconductor layers including a first semiconductor multi-layer film including aluminum (Al), an active layer, and a second semiconductor multi-layer film, a light emitting section having a mesa structure being formed on the first semiconductor multi-layer film. When viewed in a direction orthogonal to a surface of the substrate, an outer shape of the first semiconductor multi-layer film is a macroscopically smooth shape without an angular corner, and a side surface of the first semiconductor multi-layer film is coated with a passivation film and a protection film.
    Type: Grant
    Filed: June 8, 2011
    Date of Patent: August 6, 2013
    Assignee: Ricoh Company, Ltd.
    Inventors: Masayuki Numata, Shunichi Sato
  • Patent number: 8498319
    Abstract: A disclosed surface emitting laser device includes a light emitting section having a mesa structure where a lower reflection mirror, an oscillation structure, and an upper reflection mirror are laminated on a substrate, the oscillation structure including an active layer, the upper reflection mirror including a current confined structure where an oxide surrounds a current passage region, a first dielectric film that coats the entire surface of an emitting region of the light emitting section, the transparent dielectric including a part where the refractive index is relatively high and a part where the refractive index is relatively low, and a second dielectric film that coats a peripheral part on the upper surface of the mesa structure. Further, the dielectric film includes a lower dielectric film and an upper dielectric film, and the lower dielectric film is coated with the upper dielectric film.
    Type: Grant
    Filed: April 12, 2011
    Date of Patent: July 30, 2013
    Assignee: Ricoh Company, Ltd.
    Inventors: Hiroyoshi Shouji, Shunichi Sato
  • Patent number: 8483254
    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: November 24, 2009
    Date of Patent: July 9, 2013
    Assignee: Ricoh Company, Ltd.
    Inventors: Kazuhiro Harasaka, Shunichi Sato, Naoto Jikutani
  • Publication number: 20130157397
    Abstract: A manufacturing method for manufacturing a surface-emitting laser device includes the steps of forming a laminated body in which a lower reflecting mirror, a resonator structure including an active layer, and an upper reflecting layer having a selective oxidized layer are laminated on a substrate; etching the laminated body to form a mesa structure having the selective oxidized layer exposed at side surfaces thereof; selectively oxidizing the selective oxidized layer from the side surfaces of the mesa structure to form a constriction structure in which a current passing region is surrounded by an oxide; forming a separating groove at a position away from the mesa structure; passivating an outermost front surface of at least a part of the laminated body exposed when the separating groove is formed; and coating a passivated part with a dielectric body.
    Type: Application
    Filed: February 13, 2013
    Publication date: June 20, 2013
    Applicant: RICOH COMPANY, LTD.
    Inventors: Hiroyoshi Shouji, Shunichi Sato, Toshihiro Ishii, Kengo Makita, Masahiro Hayashi, Toshihide Sasaki, Akihiro Itoh
  • Patent number: 8441511
    Abstract: A disclosed surface-emitting laser element includes a substrate, multiple semiconductor layers stacked on the substrate including a resonator structure including an active layer, a semiconductor multilayer mirror on the resonator structure, and a confined structure where a current passage region is enclosed by at least an oxide generated by oxidation of part of a selective oxidation layer containing aluminum, an electrode provided around an emission region, 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 that of the central portion. The dielectric film is arranged such that a reflectance of a high-order transverse mode in a second direction is higher than that in a first direction, and a width of the current passage region in the first direction is greater than that in the second direction.
    Type: Grant
    Filed: October 22, 2010
    Date of Patent: May 14, 2013
    Assignee: Ricoh Company, Ltd.
    Inventors: Kazuhiro Harasaka, Shunichi Sato, Naoto Jikutani, Satoru Sugawara
  • Patent number: 8421837
    Abstract: A surface-emitting laser element for emitting light in a direction perpendicular to a substrate, including a substrate with a normal direction of a principal plane inclining toward one direction of <1 1 1> with respect to one direction of <1 0 0> and a mesa structure formed on the substrate and having a narrowed structure with an oxide produced by oxidizing a part of a layer to be oxidized selectively, containing aluminum and surrounding an electric current passage area, wherein a cross-section of mesa structure being parallel to the substrate is parallel to a substrate surface and orthogonal to both one direction of <1 0 0> and one direction of <1 1 1> and a length in a first direction passing through a center of the electric current passage area is more than a length in a second direction parallel to a substrate surface and orthogonal to the first direction.
    Type: Grant
    Filed: June 4, 2009
    Date of Patent: April 16, 2013
    Assignee: Ricoh Company, Ltd.
    Inventors: Akihiro Itoh, Shunichi Sato
  • Patent number: 8416822
    Abstract: A manufacturing method for manufacturing a surface-emitting laser device includes the steps of forming a laminated body in which a lower reflecting mirror, a resonator structure including an active layer, and an upper reflecting layer having a selective oxidized layer are laminated on a substrate; etching the laminated body to form a mesa structure having the selective oxidized layer exposed at side surfaces thereof; selectively oxidizing the selective oxidized layer from the side surfaces of the mesa structure to form a constriction structure in which a current passing region is surrounded by an oxide; forming a separating groove at a position away from the mesa structure; passivating an outermost front surface of at least a part of the laminated body exposed when the separating groove is formed; and coating a passivated part with a dielectric body.
    Type: Grant
    Filed: November 12, 2009
    Date of Patent: April 9, 2013
    Assignee: Ricoh Company, Ltd.
    Inventors: Hiroyoshi Shouji, Shunichi Sato, Toshihiro Ishii, Kengo Makita, Masahiro Hayashi, Toshihide Sasaki, Akihiro Itoh
  • Publication number: 20130077647
    Abstract: A surface-emission laser device comprises an active layer, cavity spacer layers provided at both sides of the active layer, reflection layers provided at respective sides of the cavity spacer layers, the reflection layers reflecting an oscillation light oscillated in the active layer and a selective oxidation layer. The selective oxidation layer is provided between a location in the reflection layer corresponding to a fourth period node of the standing wave distribution of the electric field of the oscillating light and a location in the reflection layer adjacent to the foregoing fourth period node in the direction away from the active layer and corresponding to an anti-node of the standing wave distribution of the electric field of the oscillation light.
    Type: Application
    Filed: November 20, 2012
    Publication date: March 28, 2013
    Inventors: Naoto JIKUTANI, Shunichi Sato
  • Publication number: 20130070039
    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: May 18, 2011
    Publication date: March 21, 2013
    Inventors: Kazuhiro Harasaka, Shunichi Sato, Masahiro Hayashi, Akihiro Itoh, Katsunari Hanaoka
  • Patent number: 8401049
    Abstract: A surface-emission laser diode includes a GaAs substrate, a cavity region, and upper and lower reflectors provided at a top part and a bottom part of the cavity region, the upper reflector and/or the lower reflector including a semiconductor Bragg reflector, at least a part of the semiconductor distributed Bragg reflector includes a semiconductor layer containing Al, Ga and As as major components, there being provided, between the active layer and the semiconductor layer that contains Al, Ga and As as major components, a semiconductor layer containing Al, In and P as major components adjacent to the semiconductor layer that contains Al, Ga and As as major components, with an interface formed coincident to a location of a node of electric strength distribution.
    Type: Grant
    Filed: April 30, 2012
    Date of Patent: March 19, 2013
    Assignee: Ricoh Company, Ltd.
    Inventors: Shunichi Sato, Naoto Jikutani
  • Publication number: 20130044177
    Abstract: A surface-emitting laser device is disclosed that includes a substrate connected to a heat sink; a first reflective layer formed of a semiconductor distributed Bragg reflector on the substrate; a first cavity spacer layer formed in contact with the first reflective layer; an active layer formed in contact with the first cavity spacer layer; a second cavity spacer layer formed in contact with the active layer; and a second reflective layer formed of a semiconductor distributed Bragg reflector in contact with the second cavity spacer layer. The first cavity spacer layer includes a semiconductor material having a thermal conductivity greater than the thermal conductivity of a semiconductor material forming the second cavity spacer layer.
    Type: Application
    Filed: October 26, 2012
    Publication date: February 21, 2013
    Inventor: Shunichi SATO