Patents by Inventor Masao Imaki
Masao Imaki 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: 7839908Abstract: Provided is a device capable of oscillating a plurality of oscillation modes within a laser medium for obtaining a fundamental wave output which is easy in output scaling and high in luminance, thereby enabling a second harmonic conversion which is high in efficiency. The device includes: a laser medium (5) that is planar, has a waveguide structure in a thickness direction of a cross-section that is perpendicular to an optical axis (6), and has a cyclic lens effect in a direction perpendicular to the optical axis (6) and the thickness direction; a clad (4) that is bonded onto one surface of the laser medium (5); and heat sink (3) that is bonded onto one surface side of the laser medium (5) through the clad (4), and in the device, a laser oscillation includes a laser oscillation that oscillates in a waveguide mode of the laser medium (5), and a laser oscillation that oscillates in a plurality of resonator modes that are generated by a cyclic lens effect of the laser medium (5).Type: GrantFiled: March 30, 2005Date of Patent: November 23, 2010Assignee: Mitsubishi Electric CorporationInventors: Takayuki Yanagisawa, Yoshihito Hirano, Syuhei Yamamoto, Masao Imaki, Kiyohide Sakai, Yasuharu Koyata
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Patent number: 7778291Abstract: A wavelength converting laser device includes a laser diode producing laser light and including an optical resonator having a pair of facing reflectors, including a reflecting surface having a shape reducing loss in the optical resonator, with regard to a specific horizontal transverse mode of laser light as compared to the loss in the optical resonator for other horizontal transverse modes, and a wavelength converter for converting the laser light into harmonic light.Type: GrantFiled: April 22, 2008Date of Patent: August 17, 2010Assignee: Mitsubishi Denki Kabushiki KaishaInventors: Yasuharu Koyata, Yoshihito Hirano, Masao Imaki, Kouhei Teramoto, Shigenori Shibue
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Patent number: 7724413Abstract: Provided are a speckle removing light source capable of removing speckle by using laser light whose wavelength is temporally changed and a lighting apparatus for producing an image from which the speckle is removed. Included are a light source for outputting laser light, and a light frequency modulator for temporally changing a wavelength of the laser light. The light frequency modulator has a predetermined period set for changing the wavelength of the laser light. Also, provided is a lighting apparatus, including a spatial light modulator illuminated with the laser light outputted from the speckle removing light source to produce an image. The spatial light modulator has a period set for producing the image, which is longer than the period for changing the wavelength of the laser light by the light frequency modulator.Type: GrantFiled: July 11, 2005Date of Patent: May 25, 2010Assignee: Mitsubishi Electric CorporationInventors: Yasuharu Koyata, Yoshihito Hirano, Kiyohide Sakai, Masao Imaki, Shinsuke Shikama, Jiro Suzuki, Takao Endou, Kouhei Teramoto, Shigenori Shibue
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Patent number: 7693194Abstract: A reflection element 3 disposed in an optical waveguide element 2 returns a part of light to a semiconductor laser diode element 1 so that the semiconductor laser diode element 1 oscillates in a coherent collapse mode, and a semiconductor light amplifier 7 is optically coupled to the optical waveguide element 2, and amplifies an optical output from optical waveguide element 2, so as to provide a high-power fundamental-wave light source.Type: GrantFiled: August 12, 2004Date of Patent: April 6, 2010Assignee: Mitsubishi Electric CorporationInventors: Kiyohide Sakai, Yasuharu Koyata, Masao Imaki, Yoshihito Hirano, Kouhei Teramoto, Shigenori Shibue
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Patent number: 7643707Abstract: Provided is a lighting apparatus capable of uniformly and efficiently lighting a spatial light modulator. The lighting apparatus includes: a light source for outputting laser light; a multimode optical fiber in which the laser light outputted from the light source propagates through an internal core whose lateral cross section is a substantially polygonal outer diameter shape; and spatial light modulator for producing an image with illumination light from the multimode optical fiber. In the lighting apparatus, the laser light is outputted from the light source and is propagated to the multimode optical fiber in which an outer diameter shape of the lateral cross section of the core is a substantially polygonal shape, whereby the spatial light modulator can be uniformly and efficiently lighted.Type: GrantFiled: July 11, 2005Date of Patent: January 5, 2010Assignee: Mitsubishi Electric CorporationInventors: Yasuharu Koyata, Yoshihito Hirano, Kiyohide Sakai, Masao Imaki, Shinsuke Shikama, Jiro Suzuki, Takao Endou, Kouhei Teramoto, Shigenori Shibue
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Patent number: 7605973Abstract: An allowable temperature range satisfying phase matching conditions of a wavelength conversion device is widened. A wavelength conversion light source includes a semiconductor laser diode device (1) applied with an antireflection film (3), a lens (4) arranged opposite to the semiconductor laser diode device (1), an optical fiber (5) having a Bragg grating (6) arranged in a core thereof, and a wavelength conversion device (8) formed of a nonlinear optical crystal on which light from the semiconductor laser diode device (1) is incident. In the wavelength conversion light source, the semiconductor laser diode device (1) oscillates in coherent collapse mode.Type: GrantFiled: December 3, 2004Date of Patent: October 20, 2009Assignee: Mitsubishi Electric CorporationInventors: Kiyohide Sakai, Yasuharu Koyata, Masao Imaki, Kouhei Teramoto, Shigenori Shibue
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Publication number: 20090232169Abstract: A wavelength converting laser device includes a laser diode producing laser light and including an optical resonator having a pair of facing reflectors, including a reflecting surface having a shape reducing loss in the optical resonator, with regard to a specific horizontal transverse mode of laser light as compared to the loss in the optical resonator for other horizontal transverse modes, and a wavelength converter for converting the laser light into harmonic light.Type: ApplicationFiled: April 22, 2008Publication date: September 17, 2009Applicant: MITSUBISHI DENKI KABUSHIKI KAISHAInventors: Yasuharu Koyata, Yoshihito Hirano, Masao Imaki, Kouhei Teramoto, Shigenori Shibue
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Publication number: 20090109698Abstract: Provided is a lighting apparatus capable of uniformly and efficiently lighting a spatial light modulator. The lighting apparatus includes: a light source for outputting laser light; a multimode optical fiber in which the laser light outputted from the light source propagates through an internal core whose lateral cross section is a substantially polygonal outer diameter shape; and spatial light modulator for producing an image with illumination light from the multimode optical fiber. In the lighting apparatus, the laser light is outputted from the light source and is propagated to the multimode optical fiber in which an outer diameter shape of the lateral cross section of the core is a substantially polygonal shape, whereby the spatial light modulator can be uniformly and efficiently lighted.Type: ApplicationFiled: July 11, 2005Publication date: April 30, 2009Inventors: Yasuharu Koyata, Yoshihito Hirano, Kiyohide Sakai, Masao Imaki, Shinsuke Shikama, Jiro Suzuki, Takao Endou, Kouhei Teramoto, Shigenori Shibue
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Publication number: 20090080054Abstract: Provided are a speckle removing light source capable of removing speckle by using laser light whose wavelength is temporally changed and a lighting apparatus for producing an image from which the speckle is removed. Provided is a speckle removing light source, including: a light source for outputting laser light; and a light frequency modulator for changing a wavelength of the laser light, in which: the wavelength of the laser light outputted from the light source is temporally changed by the light frequency modulator; and the light frequency modulator has a predetermined period set for changing the wavelength of the laser light. Also, provided is a lighting apparatus, including: a spatial light modulator illuminated with the laser light outputted from the speckle removing light source to produce an image, in which the spatial light modulator has a period set for producing the image, and the period is longer than the period for changing the wavelength of the laser light by the light frequency modulator.Type: ApplicationFiled: July 11, 2005Publication date: March 26, 2009Inventors: Yasuharu Koyata, Yoshihito Hirano, Kiyohide Sakai, Masao Imaki, Shinsuke Shikama, Jiro Suzuki, Takao Endou, Kouhei Teramoto, Shigenori Shibue
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Patent number: 7403549Abstract: A wavelength converting laser device includes a laser diode producing laser light and including an optical resonator having a pair of facing reflectors, including a reflecting surface having a shape reducing loss in the optical resonator, with regard to a specific horizontal transverse mode of laser light as compared to the loss in the optical resonator for other horizontal transverse modes, and a wavelength converter for converting the laser light into harmonic light.Type: GrantFiled: October 1, 2003Date of Patent: July 22, 2008Assignee: Mitsubishi Denki Kabushiki KaishaInventors: Yasuharu Koyata, Yoshihito Hirano, Masao Imaki, Kouhei Teramoto, Shigenori Shibue
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Publication number: 20080095202Abstract: Provided is a device capable of oscillating a plurality of oscillation modes within a laser medium for obtaining a fundamental wave output which is easy in output scaling and high in luminance, thereby enabling a second harmonic conversion which is high in efficiency. The device includes: a laser medium (5) that is planar, has a waveguide structure in a thickness direction of a cross-section that is perpendicular to an optical axis (6), and has a cyclic lens effect in a direction perpendicular to the optical axis (6) and the thickness direction; a clad (4) that is bonded onto one surface of the laser medium (5); and heat sink (3) that is bonded onto one surface side of the laser medium (5) through the clad (4), and in the device, a laser oscillation includes a laser oscillation that oscillates in a waveguide mode of the laser medium (5), and a laser oscillation that oscillates in a plurality of resonator modes that are generated by a cyclic lens effect of the laser medium (5).Type: ApplicationFiled: March 30, 2005Publication date: April 24, 2008Applicant: MITSUBISHI DENKI KABUSHIKI KAISHAInventors: Takayuki Yanagisawa, Yoshihito Hirano, Syuhei Yamamoto, Masao Imaki, Kiyohide Sakai, Yasuharu Koyata
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Publication number: 20080049796Abstract: An allowable temperature range satisfying phase matching conditions of a wavelength conversion device is widened. A wavelength conversion light source includes a semiconductor laser diode device (1) applied with an antireflection film (3), a lens (4) arranged opposite to the semiconductor laser diode device (1), an optical fiber (5) having a Bragg grating (6) arranged in a core thereof, and a wavelength conversion device (8) formed of a nonlinear optical crystal on which light from the semiconductor laser diode device (1) is incident. In the wavelength conversion light source, the semiconductor laser diode device (1) oscillates in coherent collapse mode.Type: ApplicationFiled: December 3, 2004Publication date: February 28, 2008Inventors: Kiyohide Sakai, Yasuharu Koyata, Masao Imaki, Kouhei Teramoto, Shigenori Shibue
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Patent number: 7301974Abstract: An optical signal emitted from a semiconductor laser is converged by a lens and then received by a single uniaxial birefringent crystal having a C axis that is inclined at an angle other than 90 degrees against a laser optical axis to output an optical signal having a polarized wave component of constant intensity corresponding to the wavelength of the optical signal regardless of temperature changes. The optical signal has an ordinary ray vibrating in a direction perpendicular to a plane including both the C axis and the laser optical axis, and an extraordinary ray vibrating in a direction perpendicular to both the ordinary ray and the laser optical axis. A first main photo detector detects the intensity of a p-polarized component of the optical signal that has passed through a polarizer and a second photo detector directly receives the optical signal converged by the lens.Type: GrantFiled: May 8, 2001Date of Patent: November 27, 2007Assignee: Mitsubishi Denki Kabushiki KaishaInventors: Masao Imaki, Yoshihito Hirano, Makoto Satou, Kenji Masuda, Akihiro Adachi, Shinichi Takagi, Yasunori Nishimura
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Patent number: 7283302Abstract: A wavelength filter includes a solid material that is optically transparent and including a pair of planar surfaces substantially parallel to each other; and a supporting member that supports the solid material on a planar surface of the solid material other than the pair of planar surfaces, the supporting member having a rigidity higher than that of the solid material. The solid material is a birefringent material of which an optical axis makes a predetermined angle with respect to a normal to the pair of planar surfaces, and the wavelength filter selects light having a wavelength that is determined by an optical length between the pair of planar surfaces by resonating the light between the pair of planar surfaces.Type: GrantFiled: March 19, 2003Date of Patent: October 16, 2007Assignee: Mitsubishi Denki Kabushiki KaishaInventors: Masao Imaki, Yoshihito Hirano, Makoto Sato, Akihiro Adachi, Shinichi Takagi, Yasunori Nisimura
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Publication number: 20070230527Abstract: A reflection element 3 disposed in an optical waveguide element 2 returns a part of light to a semiconductor laser diode element 1 so that the semiconductor laser diode element 1 oscillates in a coherent collapse mode, and a semiconductor light amplifier 7 is optically coupled to the optical waveguide element 2, and amplifies an optical output from optical waveguide element 2, so as to provide a high-power fundamental-wave light source.Type: ApplicationFiled: August 12, 2004Publication date: October 4, 2007Applicant: Mitsubishi Electric CorporationInventors: Kiyohide Sakai, Yasuharu Koyata, Masao Imaki, Yoshihito Hirano, Kouhei Teramoto, Shigenori Shibue
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Patent number: 7239654Abstract: On a plate of birefringent crystal made of an LiNbO3 crystal or an LiTaO3 crystal, a conductive substance is adhered to the whole periphery of side surfaces of the plate that intersect an incident surface of a laser beam, thereby to form a wave plate. A polarizer is provided at the latter stage of the wave plate. A wavelength is monitored based on an output from the polarizer. With this arrangement, based on the use of the LiNbO3 crystal or the LiTaO3 crystal that can be manufactured by a large quantity at low cost, it is possible to obtain polarization characteristics and wavelength discrimination characteristics that are stable against environmental changes such as temperature and external stress, by suppressing the pyroelectric effect and the piezoelectric effect of these materials.Type: GrantFiled: October 31, 2002Date of Patent: July 3, 2007Assignee: Mitsubishi Denki Kabushiki KaishaInventors: Masao Imaki, Syuhei Yamamoto, Youhei Mikami, Yoshihito Hirano, Makoto Satou, Kenji Masuda, Yasunori Nishimura, Yuji Masuyama
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Publication number: 20070041420Abstract: A solid-state laser device includes: a first solid-state laser medium 1 that emits light at a first wavelength that produces fluorescence through excitation; a second solid-state laser medium 2 that is arranged coaxially, is excited by the light at the first wavelength emitted by the first solid-state laser medium 1, and emits light at a second wavelength; two reflection means 3 and 4, which are arranged coaxially with the solid-state laser media and on both outsides of the solid-state laser media, for resonating a light component generated in an axis direction among the fluorescence; and an excitation light source 5 that excites one of the solid-state laser media, wherein the reflection means 4 has a predetermined reflectance with respect to each of the two wavelengths and laser light at the two different kinds of wavelengths is outputted separately or simultaneously with one resonator and one excitation light source.Type: ApplicationFiled: May 14, 2003Publication date: February 22, 2007Inventors: Masao Imaki, Yoshihito Hirano, Yasuharu Koyata, Kouhei Teramoto, Shigenori Shibue
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Publication number: 20060256829Abstract: A wavelength converting laser device includes a laser diode producing laser light and including an optical resonator having a pair of facing reflectors, including a reflecting surface having a shape reducing loss in the optical resonator, with regard to a specific horizontal transverse mode of laser light as compared to the loss in the optical resonator for other horizontal transverse modes; and a wavelength converter for converting the laser light into harmonic light.Type: ApplicationFiled: October 1, 2003Publication date: November 16, 2006Inventors: Yasuharu Koyata, Yoshihito Hirano, Masao Imaki, Kouhei Teramoto, Shigenori Shibue
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Publication number: 20060256437Abstract: A wavelength filter includes a solid material that is optically transparent and including a pair of planar surfaces substantially parallel to each other; and a supporting member that supports the solid material on a planar surface of the solid material other than the pair of planar surfaces, the supporting member having a rigidity higher than that of the solid material. The solid material is a birefringent material of which an optical axis makes a predetermined angle with respect to a normal to the pair of planar surfaces, and the wavelength filter selects light having a wavelength that is determined by an optical length between the pair of planar surfaces by resonating the light between the pair of planar surfaces.Type: ApplicationFiled: March 19, 2003Publication date: November 16, 2006Applicant: Mitsubishi Denki Kabushiki KaishaInventors: Masao Imaki, Yoshihito Hirano, Makoto Sato, Akihiro Adachi, Shinichi Takagi, Yasunori Nisimura
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Patent number: 6836489Abstract: An oscillation state of a semiconductor laser is decided. Injection current to the first and second light reflectors of the semiconductor laser are simultaneously swept based on the oscillation state of the semiconductor laser to obtain current conditions of the injection current to the first and second light reflectors that carry out single-mode oscillation in a target wavelength. The semiconductor laser is drive controlled with the obtained current conditions.Type: GrantFiled: November 6, 2002Date of Patent: December 28, 2004Assignee: Mitsubishi Denki Kabushiki KaishaInventors: Tetsuya Nishimura, Mitsunobu Gotoda, Yoshihito Hirano, Masao Imaki