Patents by Inventor Yasuhiro Kunitsugu
Yasuhiro Kunitsugu 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: 8519501Abstract: A back-surface-incidence semiconductor light element includes: a semiconductor substrate of a first conductivity type; a first semiconductor layer of a first conductivity type on the semiconductor substrate; a light absorbing layer on the first semiconductor layer; a second semiconductor layer on the light absorbing layer; and an impurity diffusion region of a second conductivity type in a portion of the second semiconductor layer. A region including a p-n junction between the first semiconductor layer and the impurity diffusion region, and extending through the light absorbing layer, is a light detecting portion that detects light incident on a back surface of the semiconductor substrate. A groove in the back surface of the semiconductor substrate surrounds the light detecting portion, as viewed in plan.Type: GrantFiled: May 22, 2012Date of Patent: August 27, 2013Assignee: Mitsubishi Electric CorporationInventors: Hitoshi Tada, Yasuo Nakajima, Yasuhiro Kunitsugu
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Publication number: 20130062718Abstract: A back-surface-incidence semiconductor light element includes: a semiconductor substrate of a first conductivity type; a first semiconductor layer of a first conductivity type on the semiconductor substrate; a light absorbing layer on the first semiconductor layer; a second semiconductor layer on the light absorbing layer; and an impurity diffusion region of a second conductivity type in a portion of the second semiconductor layer. A region including a p-n junction between the first semiconductor layer and the impurity diffusion region, and extending through the light absorbing layer, is a light detecting portion that detects light incident on a back surface of the semiconductor substrate. A groove in the back surface of the semiconductor substrate surrounds the light detecting portion, as viewed in plan.Type: ApplicationFiled: May 22, 2012Publication date: March 14, 2013Applicant: MITSUBISHI ELECTRIC CORPORATIONInventors: Hitoshi TADA, Yasuo NAKAJIMA, Yasuhiro KUNITSUGU
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Patent number: 7826507Abstract: A semiconductor light-emitting device includes a light generation unit generating light with an oscillation wavelength ?, a light outgoing facet from which light generated at the light generation unit emerges, a light reflecting facet at which light generated at the light generation unit is reflected, and a high reflection film at the light reflecting facet and made of a dielectric multilayered film of at least three layers. The high reflection film includes a first layer which is in contact with the light reflection facet, is constituted of Al2O3, and has a thickness smaller than ?/4n, wherein n is the refractive index of Al2O3, a second layer which is in contact with the first layer, and a third layer which is in contact with the second layer and has a refractive index different from the refractive index of the second layer.Type: GrantFiled: January 30, 2008Date of Patent: November 2, 2010Assignee: Mitsubishi Electric CorporationInventors: Harumi Nishiguchi, Hiromasu Matsuoka, Yasuyuki Nakagawa, Yasuhiro Kunitsugu
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Publication number: 20080273556Abstract: A semiconductor light-emitting device includes a light generation unit generating light with an oscillation wavelength ?, a light outgoing facet from which light generated at the light generation unit emerges, a light reflecting facet at which light generated at the light generation unit is reflected, and a high reflection film at the light reflecting facet and made of a dielectric multilayered film of at least three layers. The high reflection film includes a first layer which is in contact with the light reflection facet, is constituted of Al2O3, and has a thickness smaller than ?/4n, wherein n is the refractive index of Al2O3, a second layer which is in contact with the first layer, and a third layer which is in contact with the second layer and has a refractive index different from the refractive index of the second layer.Type: ApplicationFiled: January 30, 2008Publication date: November 6, 2008Applicant: MITSUBISHI ELECTRIC CORPORATIONInventors: Harumi Nishiguchi, Hiromasu Matsuoka, Yasuyuki Nakagawa, Yasuhiro Kunitsugu
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Publication number: 20070280307Abstract: A semiconductor laser device for emitting light at two wavelengths ?1 and ?2 comprises: a laser chip having a front end face and a rear end face; and a high reflectance film on the rear end face of the laser chip and including seven or more layers laminated one on top of another, the seven or more layers including a first layer and a last layer, the first layer being closest to the laser chip, the last layer being farthest from the laser chip. One or more of the seven or more layers of the high reflectance film, other than the first and last layers, has an optical thickness of n*?/2, where n is a natural number and ?=(?1+?2)/2. All of the seven or more layers of the high reflectance film, other than the one or more layers and other than the last layer, have an optical thickness of (2n?+1)*?/4, where n? is 0 or a positive integer. The last layer of the high reflectance film has an optical thickness of n*?/4.Type: ApplicationFiled: May 31, 2007Publication date: December 6, 2007Applicant: MITSUBISHI ELECTRIC CORPORATIONInventors: Yasuhiro Kunitsugu, Hiromasu Matsuoka
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Patent number: 7106775Abstract: A low reflective film is formed of, in sequence from a side in contact with a laser chip, a first dielectric film of a refractive index n1 and a thickness d1, a second dielectric film of a refractive index n2 and a thickness d2, a third dielectric film of a refractive index n3 and a thickness d3, and a fourth dielectric film of a refractive index n4 and a thickness d4, specifically, aluminum oxide Al2O3 with a refractive index n1=1.638 is used for the first dielectric film, silicon oxide SiO2 with a refractive index n2=n4=1.489 for the second and fourth dielectric films, tantalum oxide Ta2O5 with a refractive index n3=2.063 for the third dielectric film, respectively, resulting in a semiconductor laser device with a reflectance which is stably controllable.Type: GrantFiled: March 4, 2004Date of Patent: September 12, 2006Assignee: Mitsubishi Denki Kabushiki KaishaInventors: Hiromasu Matsuoka, Yasuhiro Kunitsugu, Harumi Nishiguchi, Tetsuya Yagi, Yasuyuki Nakagawa, Junichi Horie
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Patent number: 7039085Abstract: A semiconductor laser device includes a dielectric multilayer film with a reflectance of 40% or more, on at least one of optical exit faces of a laser chip. The dielectric multilayer film includes a film of tantalum oxide (Ta2O5) and another film of a dielectric oxide, such as aluminum oxide (Al2O3), and silicon oxide (SiO2). The tantalum oxide film has an optical absorption coefficient smaller than that of silicon (Si) and thermal stability in emission superior to that of titanium oxide (TiO2), thereby remarkably improving the catastrophic optical damage degradation level of the laser chip.Type: GrantFiled: April 21, 2004Date of Patent: May 2, 2006Assignee: Mitsubishi Denki Kabushiki KaishaInventors: Yasuhiro Kunitsugu, Hiromasu Matsuoka, Yasuyuki Nakagawa, Harumi Nishiguchi
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Publication number: 20040213314Abstract: A semiconductor laser device includes a dielectric multilayer film with a reflectance of 40% or more, on at least one of optical exit faces of a laser chip. The dielectric multilayer film includes a film of tantalum oxide (Ta2O5) and another film of a dielectric oxide, such as aluminum oxide (Al2O3), and silicon oxide (SiO2). The tantalum oxide film has an optical absorption coefficient smaller than that of silicon (Si) and thermal stability in emission superior to that of titanium oxide (TiO2) thereby remarkably improving the catastrophic optical damage degradation level of the laser chip.Type: ApplicationFiled: April 21, 2004Publication date: October 28, 2004Applicant: Mitsubishi Denki Kabushiki KaishaInventors: Yasuhiro Kunitsugu, Hiromasu Matsuoka, Yasuyuki Nakagawa, Harumi Nishiguchi
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Publication number: 20040190576Abstract: A low reflective film is formed of, in sequence from a side in contact with a laser chip, a first dielectric film of a refractive index n1 and a thickness d1, a second dielectric film of a refractive index n2 and a thickness d2, a third dielectric film of a refractive index n3 and a thickness d3, and a fourth dielectric film of a refractive index n4 and a thickness d4, specifically, aluminum oxide Al2O3 with a refractive index n1=1.638 is used for the first dielectric film, silicon oxide SiO2 with a refractive index n2=n4=1.489 for the second and fourth dielectric films, tantalum oxide Ta2O5 with a refractive index n3=2.063 for the third dielectric film, respectively, resulting in a semiconductor laser device with a reflectance which is stably controllable.Type: ApplicationFiled: March 4, 2004Publication date: September 30, 2004Applicant: Mitsubishi Denki Kabushiki KaishaInventors: Hiromasu Matsuoka, Yasuhiro Kunitsugu, Harumi Nishiguchi, Tetsuya Yagi, Yasuyuki Nakagawa, Junichi Horie
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Patent number: 5368992Abstract: In a method of producing a .lambda./4-shifted diffraction grating, a positive type photoresist is applied to a substrate so that the surface level of the photoresist is in the vicinity of the node of the nodes in a standing wave light intensity distribution in the thickness direction of the photoresist that is nearest to the substrate, the light intensity distribution is produced by interference between incident light in the film and light reflected by the substrate. Then, the photoresist is subjected to two-luminous-flux interference exposure, followed by development, providing a pattern of photoresist films regions each having an over-hanging portion.Type: GrantFiled: March 19, 1993Date of Patent: November 29, 1994Assignee: Mitsubishi Denki Kabushiki KaishaInventor: Yasuhiro Kunitsugu