Patents by Inventor Keisei Morita
Keisei Morita 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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Publication number: 20230382780Abstract: A method for producing a fluorine-containing silica glass includes degassing which includes degassing an inside of a furnace core tube under reduced pressure while heating the inside of the furnace core tube, after inserting a porous silica glass body into the furnace core tube provided in an airtight container, supplying which includes degassing a fluorine compound gas into the furnace core tube under reduced pressure, fluorine adding which includes heat-treating the porous silica glass body under reduced pressure while supplying the fluorine compound gas into the furnace core tube and discharging a gas from the furnace core tube, and transparent vitrifying which includes heat-treating in a reduced pressure at a temperature higher than temperatures in the degassing process and the fluorine adding process.Type: ApplicationFiled: September 27, 2021Publication date: November 30, 2023Applicant: SUMITOMO ELECTRIC INDUSTRIES, LTD.Inventors: Tetsuya HARUNA, Shinji ISHIKAWA, Keisei MORITA, Tatsuro HASEGAWA, Seiji ARAKAWA
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Publication number: 20230339797Abstract: A method for producing fluorine-containing silica glass includes: decompression degassing which includes degassing an inside of a furnace core tube under reduced pressure while heating the inside of the furnace core tube, after inserting a porous silica glass body into the furnace core tube provided in an airtight container; fluorine adding which includes supplying a fluorine compound gas into the furnace core tube and first heat-treating the porous silica glass body, under reduced pressure; and second heat-treating the porous silica glass body under reduced pressure at a temperature higher than temperatures in the decompression degassing process and the fluorine adding process.Type: ApplicationFiled: September 27, 2021Publication date: October 26, 2023Applicant: SUMITOMO ELECTRIC INDUSTRIES, LTD.Inventors: Shinji ISHIKAWA, Tetsuya HARUNA, Keisei MORITA, Tatsuro HASEGAWA, Seiji ARAKAWA
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Publication number: 20230331618Abstract: A method for manufacturing an optical fiber preform includes a core part deposition process and a clad part deposition process. The number of burners used in the core part deposition process is less than the number of burners used in the clad part deposition process. A distance between turning back points in a first reciprocating motion for the core deposition process is equal to or greater than a length of an effective portion of the optical fiber preform. At least three burners are used in the clad part deposition process. A distance between turning back points in a second reciprocating motion for the clad part deposition process is shorter than a distance between turning back points in the first reciprocating motion. The turning back points in the second reciprocating motion vary during the clad part deposition process.Type: ApplicationFiled: September 27, 2021Publication date: October 19, 2023Applicant: SUMITOMO ELECTRIC INDUSTRIES, LTD.Inventors: Takahiro SAITO, Keisei MORITA, Hiroki INOUE
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Publication number: 20230286851Abstract: A method for manufacturing an optical fiber preform includes generating glass particles from a glass raw material gas in a flame obtained by combustion of a combustible gas supplied to a burner and depositing the glass particles on an outer circumference of a silica glass pipe to form a hollow porous glass preform, inserting a rod into the silica glass pipe, transparently vitrifying the porous glass preform by heating the porous glass preform after inserting the rod to obtain a transparent glass preform, drawing out the rod from the silica glass pipe after the porous glass preform is transparently vitrified, and removing the silica glass pipe from the transparent glass preform by etching after drawing out the rod.Type: ApplicationFiled: March 6, 2023Publication date: September 14, 2023Applicant: SUMITOMO ELECTRIC INDUSTRIES, LTD.Inventors: Takahiro SAITO, Hiroki INOUE, Keisei MORITA
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Publication number: 20230080429Abstract: An optical fiber includes a glass fiber and a coating resin layer surrounding the outer periphery of the glass fiber. The coating resin layer has a primary resin layer that surrounds the outer periphery of the glass fiber, and a secondary resin layer that surrounds the outer periphery of the primary resin layer. The primary resin layer has a thickness of 7.5 ?m or more and 17.5 ?m or less. The primary resin layer has a Young's modulus of 0.10 MPa or greater and 0.50 MPa or less at 23° C. The secondary resin layer has a thickness of 5.0 ?m or more and 17.5 ?m or less. The secondary resin layer has an outer diameter of 165 ?m or more and 175 ?m or less. The secondary resin layer has a Young's modulus of 1200 MPa or greater and 2800 MPa or less at 23° C.Type: ApplicationFiled: August 29, 2022Publication date: March 16, 2023Applicant: SUMITOMO ELECTRIC INDUSTRIES, LTD.Inventors: Takahiro NOMURA, Kazuyuki SOHMA, Keisei MORITA, Takahiro SAITO
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Patent number: 11366267Abstract: An optical fiber according to an embodiment includes a core and a cladding. The average value n1_ave of the refractive index of the core, the minimum value nc_min of the refractive index of the cladding, and the refractive index n0 of pure silica glass satisfy relationships of n1_ave>nc_min and nc_min<n0. The cladding contains fluorine. The fluorine concentration in the cladding is adjusted to be minimum in the outermost portion of the cladding including the outer peripheral surface of the cladding.Type: GrantFiled: January 11, 2021Date of Patent: June 21, 2022Assignee: SUMITOMO ELECTRIC INDUSTRIES, LTD.Inventors: Yoshinori Yamamoto, Keisei Morita, Takemi Hasegawa, Yuki Kawaguchi
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Patent number: 11181684Abstract: An optical fiber is formed from silica glass, and includes a core, a first cladding which surrounds the core and has a refractive index lower than the refractive index of the core, and a second cladding which surrounds the first cladding and has a refractive index that is lower than the refractive index of the core and higher than the refractive index of the first cladding. The second cladding is divided into an inner region that is in contact with the first cladding and an outer region which surrounds the inner region and has a thickness that is half the thickness of the second cladding or less, while being 5 ?m or more. The residual stress in at least a part of the outer region is a compressive stress.Type: GrantFiled: August 27, 2020Date of Patent: November 23, 2021Assignee: SUMITOMO ELECTRIC INDUSTRIES, LTD.Inventors: Yoshiaki Tamura, Hirotaka Sakuma, Keisei Morita
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Patent number: 11048040Abstract: The optical fiber offered is capable of not only restraining the attenuation due to glass defects, but also reducing the increase of manufacturing cost. The optical fiber is made of silica glass and includes a core and a cladding. The cladding encloses the core and has a refractive index smaller than that of the core. When the core is divided into inner core and outer core at half of the radius of the core, the average chlorine concentration of the inner core is larger than that of the outer core. The core includes any of the alkali metal group.Type: GrantFiled: April 15, 2020Date of Patent: June 29, 2021Assignee: SUMITOMO ELECTRIC INDUSTRIES, LTD.Inventors: Hirotaka Sakuma, Yoshiaki Tamura, Keisei Morita, Yuki Kawaguchi
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Patent number: 11022749Abstract: An optical fiber includes a glass fiber and a coating resin covering an outer periphery of the glass fiber. The glass fiber includes a core and a cladding. An outer diameter of the glass fiber is 99 ?m or larger and 101 ?m or smaller. The coating resin includes a cured material of an ultraviolet curing resin composition. An outer diameter of the coating resin is 160 ?m or larger and 170 ?m or smaller. A mode field diameter for light having a wavelength of 1310 nm is 7.2 ?m or larger and 8.2 ?m or smaller. Bending loss at a wavelength of 1550 nm when wound in a ring shape having a radius of 10 mm is 0.1 dB/turn or less. Bending loss at the wavelength of 1550 nm when wound in the ring shape having the radius of 7.5 mm is 0.5 dB/turn or less.Type: GrantFiled: February 26, 2020Date of Patent: June 1, 2021Assignee: SUMITOMO ELECTRIC INDUSTRIES, LTD.Inventors: Hiroki Ishikawa, Keisei Morita, Sotaro Ida
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Publication number: 20210132291Abstract: An optical fiber according to an embodiment includes a core and a cladding. The average value n1_ave of the refractive index of the core, the minimum value nc_min of the refractive index of the cladding, and the refractive index n0 of pure silica glass satisfy relationships of n1_ave>nc_min and nc_min<n0. The cladding contains fluorine. The fluorine concentration in the cladding is adjusted to be minimum in the outermost portion of the cladding including the outer peripheral surface of the cladding.Type: ApplicationFiled: January 11, 2021Publication date: May 6, 2021Applicant: SUMITOMO ELECTRIC INDUSTRIES, LTD.Inventors: Yoshinori YAMAMOTO, Keisei MORITA, Takemi HASEGAWA, Yuki KAWAGUCHI
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Patent number: 10908354Abstract: An optical fiber includes a glass fiber and a coating resin covering an outer periphery of the glass fiber. The glass fiber includes a core, an inner cladding, a trench, and an outer cladding. An outer diameter of the glass fiber is 99 ?m or larger and 101 ?m or smaller. An outer diameter of the coating resin is 160 ?m or larger and 170 ?m or smaller. A mode field diameter for light having a wavelength of 1310 nm is 7.2 ?m or larger and 8.2 ?m or smaller. Bending loss at a wavelength of 1550 nm when wound in a ring shape having a radius of 10 mm is 0.1 dB/turn or less. Bending loss at the wavelength of 1550 nm when wound in the ring shape having the radius of 7.5 mm is 0.5 dB/turn or less.Type: GrantFiled: February 20, 2020Date of Patent: February 2, 2021Assignee: SUMITOMO ELECTRIC INDUSTRIES, LTD.Inventors: Keisei Morita, Hiroki Ishikawa, Sotaro Ida
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Publication number: 20200393613Abstract: An optical fiber is formed from silica glass, and includes a core, a first cladding which surrounds the core and has a refractive index lower than the refractive index of the core, and a second cladding which surrounds the first cladding and has a refractive index that is lower than the refractive index of the core and higher than the refractive index of the first cladding. The second cladding is divided into an inner region that is in contact with the first cladding and an outer region which surrounds the inner region and has a thickness that is half the thickness of the second cladding or less, while being 5 ?m or more. The residual stress in at least a part of the outer region is a compressive stress.Type: ApplicationFiled: August 27, 2020Publication date: December 17, 2020Applicant: SUMITOMO ELECTRIC INDUSTRIES, LTD.Inventors: Yoshiaki TAMURA, Hirotaka SAKUMA, Keisei MORITA
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Publication number: 20200278493Abstract: An optical fiber includes a glass fiber and a coating resin covering an outer periphery of the glass fiber. The glass fiber includes a core and a cladding. An outer diameter of the glass fiber is 99 ?m or larger and 101 ?m or smaller. The coating resin includes a cured material of an ultraviolet curing resin composition. An outer diameter of the coating resin is 160 ?m or larger and 170 ?m or smaller. A mode field diameter for light having a wavelength of 1310 nm is 7.2 ?m or larger and 8.2 ?m or smaller. Bending loss at a wavelength of 1550 nm when wound in a ring shape having a radius of 10 mm is 0.1 dB/turn or less. Bending loss at the wavelength of 1550 nm when wound in the ring shape having the radius of 7.5 mm is 0.5 dB/turn or less.Type: ApplicationFiled: February 26, 2020Publication date: September 3, 2020Applicant: SUMITOMO ELECTRIC INDUSTRIES, LTD.Inventors: Hiroki ISHIKAWA, Keisei MORITA, Sotaro IDA
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Publication number: 20200278492Abstract: An optical fiber includes a glass fiber and a coating resin covering an outer periphery of the glass fiber. The glass fiber includes a core, an inner cladding, a trench, and an outer cladding. An outer diameter of the glass fiber is 99 ?m or larger and 101 ?m or smaller. An outer diameter of the coating resin is 160 ?m or larger and 170 ?m or smaller. A mode field diameter for light having a wavelength of 1310 nm is 7.2 ?m or larger and 8.2 ?M or smaller. Bending loss at a wavelength of 1550 nm when wound in a ring shape having a radius of 10 mm is 0.1 dB/turn or less. Bending loss at the wavelength of 1550 nm when wound in the ring shape having the radius of 7.5 mm is 0.5 dB/turn or less.Type: ApplicationFiled: February 20, 2020Publication date: September 3, 2020Applicant: SUMITOMO ELECTRIC INDUSTRIES, LTD.Inventors: Keisei MORITA, Hiroki ISHIKAWA, Sotaro IDA
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Publication number: 20200249393Abstract: The optical fiber offered is capable of not only restraining the attenuation due to glass defects, but also reducing the increase of manufacturing cost. The optical fiber is made of silica glass and includes a core and a cladding. The cladding encloses the core and has a refractive index smaller than that of the core. When the core is divided into inner core and outer core at half of the radius of the core, the average chlorine concentration of the inner core is larger than that of the outer core. The core includes any of the alkali metal group.Type: ApplicationFiled: April 15, 2020Publication date: August 6, 2020Applicant: SUMITOMO ELECTRIC INDUSTRIES, LTD.Inventors: Hirotaka SAKUMA, Yoshiaki TAMURA, Keisei MORITA, Yuki KAWAGUCHI
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Patent number: 10723650Abstract: An optical fiber preform includes a silica-glass core portion, and a cladding portion surrounding the core portion, the cladding portion being composed of a fluorine-containing silica glass having a lower refractive index than the core portion, the core portion including a first region that does not include the central axis thereof, the first region containing a first dopant selected from sodium, potassium, and compounds thereof, and a second region that includes the central axis, the second region containing a second dopant that reduces the viscosity of the silica glass, the second dopant having a diffusion coefficient of 1×10?12 cm2/s or more and less than the first dopant at 2,000° C. to 2,300° C., in which the entire core portion has an average first dopant concentration of 10 atomic ppm or more and 2,000 atomic ppm or less and an average second dopant concentration of 10 atomic ppm or more.Type: GrantFiled: July 10, 2018Date of Patent: July 28, 2020Assignee: SUMITOMO ELECTRIC INDUSTRIES, LTD.Inventors: Keisei Morita, Yoshiaki Tamura, Hirotaka Sakuma
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Patent number: 10656329Abstract: The optical fiber offered is capable of not only restraining the attenuation due to glass defects, but also reducing the increase of manufacturing cost. The optical fiber is made of silica glass and includes a core and a cladding. The cladding encloses the core and has a refractive index smaller than that of the core. When the core is divided into inner core and outer core at half of the radius of the core, the average chlorine concentration of the inner core is larger than that of the outer core. The core includes any of the alkali metal group.Type: GrantFiled: April 17, 2019Date of Patent: May 19, 2020Assignee: SUMITOMO ELECTRIC INDUSTRIES, LTD.Inventors: Hirotaka Sakuma, Yoshiaki Tamura, Keisei Morita, Yuki Kawaguchi
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Patent number: 10550030Abstract: Provided is an optical fiber containing an alkali metal element or the like having a smaller diffusion coefficient than K and having a low Rayleigh scattering loss. An optical fiber is composed of silica glass and includes a core and a cladding arranged to surround the core which has a lower refractive index than the core. The core includes a first core including a central axis and a second core arranged to surround the first core. The average concentration of an alkali metal element or alkaline-earth metal element in the first core is 10 mol ppm or less. The average concentration of chlorine in the first core is 2000 mol ppm or more. The average concentration of an alkali metal element or alkaline-earth metal element in the second core is 10 mol ppm or more. The average concentration of chlorine in the second core is 10 to 600 mol ppm.Type: GrantFiled: August 23, 2018Date of Patent: February 4, 2020Assignee: SUMITOMO ELECTRIC INDUSTRIES, LTD.Inventors: Hirotaka Sakuma, Yoshiaki Tamura, Keisei Morita
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Publication number: 20190324195Abstract: The optical fiber offered is capable of not only restraining the attenuation due to glass defects, but also reducing the increase of manufacturing cost. The optical fiber is made of silica glass and includes a core and a cladding. The cladding encloses the core and has a refractive index smaller than that of the core. When the core is divided into inner core and outer core at half of the radius of the core, the average chlorine concentration of the inner core is larger than that of the outer core. The core includes any of the alkali metal group.Type: ApplicationFiled: April 17, 2019Publication date: October 24, 2019Applicant: SUMITOMO ELECTRIC INDUSTRIES, LTD.Inventors: Hirotaka SAKUMA, Yoshiaki TAMURA, Keisei MORITA, Yuki KAWAGUCHI
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Publication number: 20190292089Abstract: The present embodiment relates to an optical fiber preform manufacturing method in which two or more kinds of alkali metal elements are diffused and doped to an inner surface of a glass pipe. The manufacturing method includes: a first drying step performed at a temperature equal to or lower than a lowest temperature among melting point temperatures of the alkali metal salt raw materials; and a second drying step performed at a temperature which is equal to or higher than a highest temperature among the melting point temperatures of the alkali metal salt raw materials and at which vapor pressures of the alkali metal salt raw materials are 2 mmHg or lower.Type: ApplicationFiled: June 11, 2019Publication date: September 26, 2019Applicant: SUMITOMO ELECTRIC INDUSTRIES, LTD.Inventors: Hirotaka SAKUMA, Yoshiaki TAMURA, Keisei MORITA