Patents by Inventor Kentaro Furusawa
Kentaro Furusawa 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).
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Patent number: 8964803Abstract: A light source apparatus includes a laser oscillator equipped with a first optical resonator, a plurality of second optical resonators including input portions respectively connected in parallel to the first optical resonator, a plurality of light extraction units configured to extract a light beam from an output portion of each second optical resonator, and a light multiplexing unit configured to multiplex the light beam extracted from each light extraction unit, wherein the light source apparatus causes the light multiplexing unit to output a multiplexed light beam passed through the plurality of second optical resonators, an optical member having refractive index dispersion and an optical amplification medium are disposed in each of the plurality of second optical resonators, and the optical amplification media of the plurality of second optical resonators are different from each other in maximum gain wavelength.Type: GrantFiled: June 6, 2011Date of Patent: February 24, 2015Assignee: Canon Kabushiki KaishaInventors: Tomohiro Yamada, Kentaro Furusawa
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Patent number: 8605768Abstract: The present invention provides a laser apparatus capable of improving a scan speed and achieving a scan rate equal to or more than 1 MHz, and an optical tomographic imaging apparatus using the laser apparatus as a light source. The laser apparatus includes a ring resonator, the ring resonator having a structure in which a first modulator, a normal dispersion region, a second modulator and an anomalous dispersion region are arranged in this order, and in this arrangement, a gain medium is included, and being configured so that modulation with respect to the second modulator can be caused to be phase modulation by periodically superimposing phase modulation on modulation with respect to the first modulator.Type: GrantFiled: May 11, 2009Date of Patent: December 10, 2013Assignee: Canon Kabushiki KaishaInventors: Kentaro Furusawa, Natsuhiko Mizutani, Kazuhide Miyata
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Patent number: 8488125Abstract: An optical tomography imaging a tomogram by using a coherent light by a backscattering light of a measured object and a reflected light of a reference mirror, which has supercontinuum light sources, an optical system having group velocity dispersion connected to the supercontinuum light source, an optical detection element detecting a coherent light by a backscattering light of the measured object and a reflected light of the reference mirror, a timing detection element detecting a timing of each wavelength component in an output light from the optical system having the group velocity dispersion, and a unit sampling a signal from the optical detector by using a timing signal from the timing detection element with a signal from the supercontinuum light source as a trigger, and detecting an optical tomogram signal imaging a tomogram, thereby acquiring an optical tomogram at a higher speed than a conventional SS-OCT.Type: GrantFiled: May 12, 2009Date of Patent: July 16, 2013Assignee: Canon Kabushiki KaishaInventors: Kentaro Furusawa, Natsuhiko Mizutani, Ryo Kuroda
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Patent number: 8306378Abstract: Optical pulse compensator having a chirp unit including a normal dispersion fiber that provides a positive chirp to an input pulse and having a dispersion compensator including an anomalous fiber is provided. The nonlinear coefficient and the absolute value of the second-order group-velocity dispersion of the anomalous fiber that forms the dispersion compensator is set such that a soliton order becomes one or more, and the fiber length of the anomalous dispersion fiber is made to be equal to or smaller than a length required for optical soliton formation.Type: GrantFiled: March 15, 2012Date of Patent: November 6, 2012Assignee: Canon Kabushiki KaishaInventors: Takashi Katagiri, Toshihiko Ouchi, Kentaro Furusawa
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Publication number: 20120177332Abstract: Optical pulse compensator having a chirp unit including a normal dispersion fiber that provides a positive chirp to an input pulse and having a dispersion compensator including an anomalous fiber is provided. The nonlinear coefficient and the absolute value of the second-order group-velocity dispersion of the anomalous fiber that forms the dispersion compensator is set such that a soliton order becomes one or more, and the fiber length of the anomalous dispersion fiber is made to be equal to or smaller than a length required for optical soliton formation.Type: ApplicationFiled: March 15, 2012Publication date: July 12, 2012Applicant: CANON KABUSHIKI KAISHAInventors: Takashi Katagiri, Toshihiko Ouchi, Kentaro Furusawa
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Patent number: 8179932Abstract: A pulse laser apparatus includes a laser configured to generate a pulse of a laser beam, a fiber amplifier, and a pulse compressor. The fiber amplifier includes a rare-earth doped fiber that exhibits normal dispersion at a wavelength of the laser beam generated from the laser. The pulse laser apparatus further includes a unit configured to give a loss to energy portions in a wavelength region corresponding to a zero-dispersion wavelength of the rare-earth doped fiber and/or a wavelength region longer than the zero-dispersion wavelength within a wavelength spectrum of the laser beam having been chirped in the fiber amplifier.Type: GrantFiled: April 25, 2011Date of Patent: May 15, 2012Assignee: Canon Kabushiki KaishaInventors: Toshihiko Ouchi, Takashi Katagiri, Kentaro Furusawa
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Patent number: 8170386Abstract: Optical pulse compressor having a chirp unit including a normal dispersion fiber that provides a positive chirp to an input pulse and having a dispersion compensator including an anomalous fiber is provided. The nonlinear coefficient and the absolute value of the second-order group-velocity dispersion of the anomalous fiber that forms the dispersion compensator is set such that a soliton order becomes one or more, and the fiber length of the anomalous dispersion fiber is made to be equal to or smaller than a length required for optical soliton formation.Type: GrantFiled: January 16, 2009Date of Patent: May 1, 2012Assignee: Canon Kabushiki KaishaInventors: Takashi Katagiri, Toshihiko Ouchi, Kentaro Furusawa
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Publication number: 20110304853Abstract: A light source apparatus includes a laser oscillator equipped with a first optical resonator, a plurality of second optical resonators including input portions respectively connected in parallel to the first optical resonator, a plurality of light extraction units configured to extract a light beam from an output portion of each second optical resonator, and a light multiplexing unit configured to multiplex the light beam extracted from each light extraction unit, wherein the light source apparatus causes the light multiplexing unit to output a multiplexed light beam passed through the plurality of second optical resonators, an optical member having refractive index dispersion and an optical amplification medium are disposed in each of the plurality of second optical resonators, and the optical amplification media of the plurality of second optical resonators are different from each other in maximum gain wavelength.Type: ApplicationFiled: June 6, 2011Publication date: December 15, 2011Applicant: CANON KABUSHIKI KAISHAInventors: Tomohiro Yamada, Kentaro Furusawa
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Publication number: 20110210252Abstract: A pulse laser apparatus includes a laser configured to generate a pulse of a laser beam, a fiber amplifier, and a pulse compressor. The fiber amplifier includes a rare-earth doped fiber that exhibits normal dispersion at a wavelength of the laser beam generated from the laser. The pulse laser apparatus further includes a unit configured to give a loss to energy portions in a wavelength region corresponding to a zero-dispersion wavelength of the rare-earth doped fiber and/or a wavelength region longer than the zero-dispersion wavelength within a wavelength spectrum of the laser beam having been chirped in the fiber amplifier.Type: ApplicationFiled: April 25, 2011Publication date: September 1, 2011Applicant: CANON KABUSHIKI KAISHAInventors: Toshihiko Ouchi, Takashi Katagiri, Kentaro Furusawa
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Publication number: 20110155916Abstract: The present invention provides a laser apparatus capable of improving a scan speed and achieving a scan rate equal to or more than 1 MHz, and an optical tomographic imaging apparatus using the laser apparatus as a light source. The laser apparatus includes a ring resonator, the ring resonator having a structure in which a first modulator, a normal dispersion region, a second modulator and an anomalous dispersion region are arranged in this order, and in this arrangement, a gain medium is included, and being configured so that modulation with respect to the second modulator can be caused to be phase modulation by periodically superimposing phase modulation on modulation with respect to the first modulator.Type: ApplicationFiled: May 11, 2009Publication date: June 30, 2011Applicant: CANON KABUSHIKI KAISHAInventors: Kentaro Furusawa, Natsuhiko Mizutani, Kazuhide Miyata
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Patent number: 7953130Abstract: A pulse laser apparatus includes a laser configured to generate a pulse of a laser beam, a fiber amplifier, and a pulse compressor. The fiber amplifier includes a rare-earth doped fiber that exhibits normal dispersion at a wavelength of the laser beam generated from the laser. The pulse laser apparatus further includes a unit configured to give a loss to energy portions in a wavelength region corresponding to a zero-dispersion wavelength of the rare-earth doped fiber and/or a wavelength region longer than the zero-dispersion wavelength within a wavelength spectrum of the laser beam having been chirped in the fiber amplifier.Type: GrantFiled: January 15, 2009Date of Patent: May 31, 2011Assignee: Canon Kabushiki KaishaInventors: Toshihiko Ouchi, Takashi Katagiri, Kentaro Furusawa
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Publication number: 20100309480Abstract: An optical tomography imaging a tomogram by using a coherent light by a backscattering light of a measured object and a reflected light of a reference mirror, which has supercontinuum light sources, an optical system having group velocity dispersion connected to the supercontinuum light source, an optical detection element detecting a coherent light by a backscattering light of the measured object and a reflected light of the reference mirror, a timing detection element detecting a timing of each wavelength component in an output light from the optical system having the group velocity dispersion, and a unit sampling a signal from the optical detector by using a timing signal from the timing detection element with a signal from the supercontinuum light source as a trigger, and detecting an optical tomogram signal imaging a tomogram, thereby acquiring an optical tomogram at a higher speed than a conventional SS-OCT.Type: ApplicationFiled: May 12, 2009Publication date: December 9, 2010Applicant: CANON KABUSHIKI KAISHAInventors: Kentaro Furusawa, Natsuhiko Mizutani, Ryo Kuroda
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Patent number: 7760361Abstract: A detection apparatus arranges a light source, a curved surface prism having a curved surface and a plane surface, a metal film placed on the plane surface of the prism to be held adjacently to a test sample, and a reflecting member for reflecting light such that light emitted by the light source enters the prism through the curved surface and is reflected by the metal film, then by the reflecting member, and again by the metal film. The detection apparatus is adapted to detect an optical change in the test sample by means of surface plasmon generated on the metal film. In the detection apparatus, divergent light is made to enter the prism through the curved surface to collimate the incident light by means of the curved surface. The apparatus can suppress the broadening of the resonant bandwidth so as to operate as a monitor with a higher degree of precision.Type: GrantFiled: July 8, 2008Date of Patent: July 20, 2010Assignee: Canon Kabushiki KaishaInventor: Kentaro Furusawa
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Publication number: 20100045996Abstract: A sensing apparatus comprises a sensing element having a metal member of a periodic structure formed on a substrate, a light source for projecting a light beam to the sensing element, and a photosensor for sensing the light beam from the sensing element, wherein the sensing element has an optical waveguide layer between the substrate and the metal member, and the light beam illuminated from the light source and propagating in the optical waveguide layer and the light of a Rayleigh mode formed by the metal member are phase-matched.Type: ApplicationFiled: March 17, 2008Publication date: February 25, 2010Applicant: CANON KABUSHIKI KAISHAInventors: Kentaro Furusawa, Natsuhiko Mizutani, Ryo Kuroda
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Patent number: 7593111Abstract: A plasmon sensor apparatus using a metallic fine periodic structure designed to reduce the dependences of the resonance wavelength and sensitivity on the incident angle. The plasmon sensor apparatus has a sensing element including a metallic member having periodic slit openings and metallic portions, and a substrate on which the metallic member is held, a light source which emits light so that the light is incident on the sensing element, and a photodetector which detects light obtained from the light source. If the period of the slit openings is ?; the width of the metallic portions is d; and the thickness of the metallic member is h, the aspect ratio h/(??d) of the slit openings is 3 or higher and the opening width (??d) is equal to or smaller than the wavelength of light applied from the light source to the sensing element.Type: GrantFiled: July 17, 2008Date of Patent: September 22, 2009Assignee: Canon Kabushiki KaishaInventors: Kentaro Furusawa, Natsuhiko Mizutani, Ryo Kuroda
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Publication number: 20090213880Abstract: A pulse laser apparatus includes a laser configured to generate a pulse of a laser beam, a fiber amplifier, and a pulse compressor. The fiber amplifier includes a rare-earth doped fiber that exhibits normal dispersion at a wavelength of the laser beam generated from the laser. The pulse laser apparatus further includes a unit configured to give a loss to energy portions in a wavelength region corresponding to a zero-dispersion wavelength of the rare-earth doped fiber and/or a wavelength region longer than the zero-dispersion wavelength within a wavelength spectrum of the laser beam having been chirped in the fiber amplifier.Type: ApplicationFiled: January 15, 2009Publication date: August 27, 2009Applicant: CANON KABUSHIKI KAISHAInventors: Toshihiko Ouchi, Takashi Katagiri, Kentaro Furusawa
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Publication number: 20090190893Abstract: Optical pulse compressor having a chirp unit including a normal dispersion fiber that provides a positive chirp to an input pulse and having a dispersion compensator including an anomalous fiber is provided. The nonlinear coefficient and the absolute value of the second-order group-velocity dispersion of the anomalous fiber that forms the dispersion compensator is set such that a soliton order becomes one or more, and the fiber length of the anomalous dispersion fiber is made to be equal to or smaller than a length required for optical soliton formation.Type: ApplicationFiled: January 16, 2009Publication date: July 30, 2009Applicant: CANON KABUSHIKI KAISHAInventors: Takashi Katagiri, Toshihiko Ouchi, Kentaro Furusawa
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Publication number: 20090027680Abstract: A detection apparatus arranges a light source, a curved surface prism having a curved surface and a plane surface, a metal film placed on the plane surface of the prism to be held adjacently to a test sample, and a reflecting member for reflecting light such that light emitted by the light source enters the prism through the curved surface and is reflected by the metal film, then by the reflecting member, and again by the metal film. The detection apparatus is adapted to detect an optical change in the test sample by means of surface plasmon generated on the metal film. In the detection apparatus, divergent light is made to enter the prism through the curved surface to collimate the incident light by means of the curved surface. The apparatus can suppress the broadening of the resonant bandwidth so as to operate as a monitor with a higher degree of precision.Type: ApplicationFiled: July 8, 2008Publication date: January 29, 2009Applicant: CANON KABUSHIKI KAISHAInventor: Kentaro Furusawa
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Publication number: 20090021742Abstract: A plasmon sensor apparatus using a metallic fine periodic structure designed to reduce the dependences of the resonance wavelength and sensitivity on the incident angle. The plasmon sensor apparatus has a sensing element including a metallic member having periodic slit openings and metallic portions, and a substrate on which the metallic member is held, a light source which emits light so that the light is incident on the sensing element, and a photodetector which detects light obtained from the light source. If the period of the slit openings is ?; the width of the metallic portions is d; and the thickness of the metallic member is h, the aspect ratio h/(??d) of the slit openings is 3 or higher and the opening width (??d) is equal to or smaller than the wavelength of light applied from the light source to the sensing element.Type: ApplicationFiled: July 17, 2008Publication date: January 22, 2009Applicant: CANON KABUSHIKI KAISHAInventors: Kentaro Furusawa, Natsuhiko Mizutani, Ryo Kuroda
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Patent number: 6968107Abstract: An optical fiber structure having a holey fiber arranged in a holey outer support structure made up of holey tubes encased in a thin walled outer jacket. The holey fiber may have a solid core surrounded by a holey cladding having a plurality of rings of holes. With the invention it is possible to produce robust, coated and jacketed fibers with microstructured core features of micrometer size relatively easily using existing fiber fabrication technology. This improvement is a result of the outer holey structure which reduces the thermal mass of the supporting structure and makes it possible to reliably and controllably retain small hole features during the fiber fabrication process.Type: GrantFiled: August 10, 2001Date of Patent: November 22, 2005Assignee: University of SouthamptonInventors: Walter Belardi, Kentaro Furusawa, Tanya Monro, David Richardson, Paul Turner