Patents by Inventor Yasutake Ohishi
Yasutake Ohishi 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: 6912083Abstract: An ASE light source offers high outputs even in a wavelength band of 1,490 to 1,525 nm. The ASE light source outputs spontaneous emission light generated from Tm-doped optical fibers. Then, the ASE light source outputs amplified light obtained by using Er-doped optical fibers to amplify the output from the Tm-doped optical fibers and spontaneous emission light generated from the Er-doped optical fibers so that the amplified light and the spontaneous emission light are superimposed on each other.Type: GrantFiled: March 25, 2004Date of Patent: June 28, 2005Assignee: NTT Electronics CorporationInventors: Yasutake Ohishi, Koichi Nakagawa, Terutoshi Kanamori, Yousuke Hiraki
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Publication number: 20040184820Abstract: An ASE light source offers high outputs even in a wavelength band of 1,490 to 1,525 nm. The ASE light source outputs spontaneous emission light generated from Tm-doped optical fibers. Then, the ASE light source outputs amplified light obtained by using Er-doped optical fibers to amplify the output from the Tm-doped optical fibers and spontaneous emission light generated from the Er-doped optical fibers so that the amplified light and the spontaneous emission light are superimposed on each other.Type: ApplicationFiled: March 25, 2004Publication date: September 23, 2004Inventors: Yasutake Ohishi, Koichi Nakagawa, Terutoshi Kanamori, Yousuke Hiraki
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Patent number: 6417963Abstract: A tellurite glass as a glass material of optical fiber and optical waveguide has a composition of 0<Bi2O3≦20 (mole %), 0≦Na2O≦35 (mole %), 0≦ZnO≦35 (mole %), and 55≦TeO2≦90 (mole %). The tellurite glass allows an optical amplifier and a laser device that have broadband and low-noise characteristics. In a splicing structure of non silica-based optical fiber (as a first fiber) and a silica-based optical fiber (as a second fiber), optical axes of the first and second optical fibers are held at different angles &thgr;1 and &thgr;2 (&thgr;1≠&thgr;2) respectively from a vertical axis of a boundary surface between their spliced ends, and a relationship between the angles &thgr;1 and &thgr;2 satisfies Snell's law represented by an equation of sin &thgr;1/sin &thgr;2=n2/n1 (where n1 is a refractive index of the first optical fiber and n2 is a refractive index of the second optical fiber) at the time of splicing the first and second optical fibers.Type: GrantFiled: December 28, 2001Date of Patent: July 9, 2002Assignee: Nippon Telegraph and Telephone CorporationInventors: Yasutake Ohishi, Atsushi Mori, Makoto Yamada, Hirotaka Ono, Terutoshi Kanamori, Toshiyuki Shimada
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Publication number: 20020080474Abstract: A tellurite glass as a glass material of optical fiber and optical waveguide has a composition of 0<Bi2O3 ≦20 (mole %), 0≦Na2O≦35 (mole %), 0≦ZnO≦35 (mole %), and 55≦TeO2≦90 (mole %). The tellurite glass allows an optical amplifier and a laser device that have broadband and low-noise characteristics. In a splicing structure of non silica-based optical fiber (as a first fiber) and a silica-based optical fiber (as a second fiber), optical axes of the first and second optical fibers are held at different angles &thgr;1 and &thgr;2 (&thgr;1≠&thgr;2) respectively from a vertical axis of a boundary surface between their spliced ends, and a relationship between the angles &thgr;1 and &thgr;2 satisfies Snell's law represented by an equation of sin &thgr;1/sin &thgr;2=n2 /n1 (where n1 is a refractive index of the first optical fiber and n2 is a refractive index of the second optical fiber) at the time of splicing the first and second optical fibers.Type: ApplicationFiled: December 28, 2001Publication date: June 27, 2002Applicant: NIPPON TELEGRAPH AND TELEPHONE CORPORATIONInventors: Yasutake Ohishi, Atsushi Mori, Makoto Yamada, Hirotaka Ono, Terutoshi Kanamori, Toshiyuki Shimada
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Patent number: 6373863Abstract: An apparatus, composition, and method for producing an optical gain. The apparatus includes: an optical fiber having a core and a multiple cladding, the core being doped with Yb3+; a light source producing light at a wavelength in a range of from about 0.8 to about 1.06 microns to energize the yb3+ to produce laser action; and wherein the core is essentially devoid of Nd3+.Type: GrantFiled: June 19, 1997Date of Patent: April 16, 2002Assignee: Rutgers UniversityInventors: Yasutake Ohishi, Elias Snitzer
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Patent number: 6356387Abstract: A tellurite glass as a glass material of optical fiber and optical waveguide has a composition of 0<Bi2O3≦20 (mole %), 0≦Na2O≦35 (mole %), 0≦ZnO≦35 (mole %), and 55≦TeO2≦90 (mole %). The tellurite glass allows an optical amplifier and a laser device that have broadband and low-noise characteristics. In a splicing structure of non silica-based optical fiber (as a first fiber) and a silica-based optical fiber (as a second fiber), optical axes of the first and second optical fibers are held at different angles &thgr;1 and &thgr;2 (&thgr;1≠&thgr;2) respectively from a vertical axis of a boundary surface between their spliced ends, and a relationship between the angles &thgr;1 and &thgr;2 satisfies Snell's law represented by an equation of sin &thgr;1/sin &thgr;2=n2/n1 (where n1 is a refractive index of the first optical fiber and n2 is a refractive index of the second optical fiber) at the time of splicing the first and second optical fibers.Type: GrantFiled: November 14, 2000Date of Patent: March 12, 2002Assignee: Nippon Telegraph and Telephone CorporationInventors: Yasutake Ohishi, Atsushi Mori, Makoto Yamada, Hirotaka Ono, Terutoshi Kanamori, Toshiyuki Shimada
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Patent number: 6278719Abstract: An optical amplification medium doped with Er3+ ions is selected from the group of a fluoride glass, a chalcogenide glass, a telluride glass, a halide crystal, and a lead oxide based glass. The Er3+ ions are excited by light of at least one wavelength in the range of 0.96 &mgr;m to 0.98 &mgr;m. A laser or an optical amplifier includes this optical amplification medium doped with Er3+ ions. Furthermore, an optical amplification method performs an optical amplification using the optical amplifier having the optical amplification medium doped with Er3+ ions. Thus, the laser to be applied in the field of optical communication, the optical amplifier having the characteristics of low noise and high gain, and the optical amplification method can be provided.Type: GrantFiled: March 27, 2000Date of Patent: August 21, 2001Assignee: Nippon Telegraph and Telephone CorporationInventors: Yasutake Ohishi, Makoto Yamada, Terutoshi Kanamori, Shoichi Sudo
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Patent number: 6266181Abstract: A tellurite glass as a glass material of optical fiber and optical waveguide has a composition of 0<Bi2O3≦20 (mole %), 0≦Na2O≦35 (mole %), 0≦ZnO≦35 (mole %), and 55≦TeO2≦90 (mole %). The tellurite glass allows an optical amplifier and a laser device that have broadband and low-noise characteristics. In a splicing structure of non silica-based optical fiber (as a first fiber) and a silica-based optical fiber (as a second fiber), optical axes of the first and second optical fibers are held at different angles &thgr;1 and &thgr;2 (&thgr;1≠&thgr;2) respectively from a vertical axis of a boundary surface between their spliced ends, and a relationship between the angles &thgr;1 and &thgr;2 satisfies Snell's law represented by an equation of sin &thgr;1/sin &thgr;2=n2/n1 (where n1 is a refractive index of the first optical fiber and n2 is a refractive index of the second optical fiber) at the time of splicing the first and second optical fibers.Type: GrantFiled: February 13, 1998Date of Patent: July 24, 2001Assignee: Nippon Telegraph and Telephone CorporationInventors: Yasutake Ohishi, Atsushi Mori, Makoto Yamada, Hirotaka Ono, Terutoshi Kanamori, Toshiyuki Shimada
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Patent number: 6236496Abstract: An optical amplifier includes an erbium doped fiber of which at least one of a core part and a clad part is doped with erbium, excitation light sources or exciting the optical fiber, optical means for inputting excitation light from the excitation light source and signal light to the Er-doped fiber, and an optical isolator. The erbium doped fiber is a 1.58 &mgr;m band optical fiber having an equivalent fiber length as a product of a fiber length (m) and an erbium doping concentration (ppm by weight), which length provides a signal gain obtained at a wavelength of the excitation light source used for excitation of the erbium doped fiber of more than a predetermined practical reference value.Type: GrantFiled: December 10, 1997Date of Patent: May 22, 2001Assignee: Nippon Telegraph and Telephone CorporationInventors: Makoto Yamada, Hirotaka Ono, Terutoshi Kanamori, Yasutake Ohishi
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Patent number: 6205164Abstract: An optical amplification medium doped with Er3+ ions is selected from the group of a fluoride glass, a chalcogenide glass, a telluride glass, a halide crystal, and a lead oxide based glass. The Er3+ ions are excited by light of at least one wavelength in the range of 0.96 &mgr;m to 0.98 &mgr;m. A laser or an optical amplifier includes this optical amplification medium doped with Er3+ ions. Furthermore, an optical amplification method performs an optical amplification using the optical amplifier having the optical amplification medium doped with Er3+ ions. Thus, the laser to be applied in the field of optical communication, the optical amplifier having the characteristics of low noise and high gain, and the optical amplification method can be provided.Type: GrantFiled: June 3, 1997Date of Patent: March 20, 2001Assignee: Nippon Telegraph and Telephone CorporationInventors: Yasutake Ohishi, Makoto Yamada, Terutoshi Kanamori, Shoichi Sudo
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Patent number: 5774620Abstract: This invention relates to fluoride glass with a specific composition having wide infrared transmission. A fluoride optical fiber using this fluoride glass can give high efficiency with a low loss. The fluoride optical fiber having a second cladding on the outer periphery of a first cladding can adjust the refractive index of the first cladding suitably.Type: GrantFiled: January 24, 1997Date of Patent: June 30, 1998Assignee: Nippon Telegraph and Telephone CorporationInventors: Yoshiki Nishida, Terutoshi Kanamori, Tadashi Sakamoto, Yasutake Ohishi, Shoichi Sudo
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Patent number: 5668659Abstract: An amplifying optical fiber includes a core containing Tm ions as activation ions and a clad containing at least one of Tb ions and Eu ions. Alternatively, the amplifying optical fiber includes a core composed of more than two layers. Tm is contained in more than one of the more than two layers as activation ions and at least one of Tb ions and Eu ions is contained in more than one of the more than two in which Tm is not contained.Type: GrantFiled: September 25, 1995Date of Patent: September 16, 1997Assignee: Nippon Telegraph and Telephone CorporationInventors: Tadashi Sakamoto, Terutoshi Kanamori, Makoto Yamada, Makoto Shimizu, Yasutake Ohishi, Shoichi Sudo
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Patent number: 5486947Abstract: Fluoride glass-based optical fiber for an optical amplifier which contains rare earth metal ions in the core glass has a relative refractive index difference .DELTA.n between the core and the cladding of 1.4% or more. The core glass contains PbF.sub.2 in a proportion of 25 mol % or less based on the total composition of the core glass. The fluoride glass is doped with rare earth metal ions, and part of the fluorine in the glass may be substituted by at least one halogen Pr.sup.3+, Pr.sup.3+ --Yb.sup.3+, Pr.sup.3+ --Nd.sup.3+, or Pr.sup.3+ --Er.sup.3+ can be doped as the rare earth metal ions. Chlorine, bromine or iodine may be used as the halogen.Type: GrantFiled: May 6, 1994Date of Patent: January 23, 1996Assignee: Nippon Telegraph and Telephone CorporationInventors: Yasutake Ohishi, Terutoshi Kanamori, Yoshiki Nishida, Atsushi Mori, Shoichi Sudo
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Patent number: 5351335Abstract: Fluoride glass-based optical fiber for an optical amplifier which contains rare earth metal ions in the core glass has a relative refractive index difference .DELTA..sub.n between the core and the cladding of 1.4% or more. The core glass contains PbF.sub.2 in a proportion of 25 mol % or less based on the total composition of the core glass . The fluoride glass is doped with rare earth metal ions, and part of the fluorine in the glass may be substituted by at least one halogen. Pr.sup.3+, Pr.sup.3+ --Yb.sup.3+, Pr.sup.3+ --Nd.sup.3+, or Pr.sup.3+ --Er.sup.3+ can be doped as the rare earth metal ions. Chlorine, bromine or iodine may be used as the halogen.Type: GrantFiled: August 25, 1992Date of Patent: September 27, 1994Assignee: Nippon Telegraph and Telephone CorporationInventors: Yasutake Ohishi, Terutoshi Kanamori, Yoshiki Nishida, Atsushi Mori, Shoichi Sudo
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Patent number: 5309452Abstract: A system for producing an optical gain. The system includes an optical fiber having a core and a cladding, the core being doped with Pr.sup.3+ ; and a source producing light to energize the Pr.sup.3+ to the .sup.1 G.sub.4 state and produce an optical gain by a .sup.1 G.sub.4 -.sup.3 H.sub.5 transition at a wavelength in the range of 1.25 to 1.34 microns. The system also includes a method of making and a method of using the same.Type: GrantFiled: January 31, 1992Date of Patent: May 3, 1994Assignee: Rutgers UniversityInventors: Yasutake Ohishi, Elias Snitzer
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Patent number: 5145508Abstract: A method for preparing a homogenous fluoride glass containing high purity BaF.sub.2 through the CVD process using a gaseous mixture containing a barium .beta.-diketonate complex service as a first starting material and represented by the following general formula (1) of: ##STR1## where (i) R and R' are each --C(CH.sub.3).sub.3 ; or (ii) R is CH.sub.2 CH.sub.2 CH.sub.3 and R' is --C(CH.sub.3).sub.3 ; or (iii) R and R' are each CF.sub.3 ;a gaseous or vaporizable compound of the metallic element constituting said fluoride glass, the gaseous or vaporizable compound serving as a second starting material; and a fluorine-containing gas serving as fluorinating agent. Further provided is a process for preparing a perform for a fluoride optical fiber which is low in transmission loss, by depositing the fluoride glass over the interior wall of a cylindrical tube or the wall of rod-like glass substrate through the CVD process following by collapsing.Type: GrantFiled: March 11, 1991Date of Patent: September 8, 1992Assignee: Nippon Telegraph and Telephone CorporationInventors: Kazuo Fujiura, Yasutake Ohishi, Michiya Fujiki, Terutoshi Kanamori, Shiro Takahashi
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Patent number: 5071460Abstract: Provided is a process for preparing a homogeneous fluoride glass containing high purity BaF.sub.2 through the CVD process characterized in that the used gaseous mixture comprising: a barium .beta.-diketonate complex serving as a first starting material and represented by the following general formula (1) of: ##STR1## wherein R is an alkyl group having 1 to 7 carbon atoms, R' is a substituted alkyl group having fluorine atoms substituting hydrogen atoms and represented by C.sub.n F.sub.2n+1 where n is an integer of from 1 to 3;a gaseous or vaporizable compound of the metallic element constituting said fluoride glass, the gaseous or vaporizable compound serving as a second starting material; and a fluorine-containing gas serving as fluorinating agent.Type: GrantFiled: March 1, 1989Date of Patent: December 10, 1991Assignee: Nippon Telegraph and Telephone CorporationInventors: Kazuo Fujiura, Yasutake Ohishi, Michiya Fujiki, Terutoshi Kanamori, Shiro Takahashi