Patents by Inventor Tetsuya Haruna

Tetsuya Haruna 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).

  • Publication number: 20120014654
    Abstract: Provided is an optical fiber having a large relative refractive index difference and a reduced transmission loss, as well as a manufacturing method therefor. An optical fiber preform 100, which is made of silica glass as the main element and which includes a core region having a relative refractive index difference of 2.0% or more and less than 3.0% on the basis of the refractive index of pure silica glass and a first cladding region provided around the core region and having a relative refractive index difference of ?0.8% or more and less than ?0.3% on the basis of the refractive index of pure silica glass, is drawn into a glass fiber. The glass fiber thus drawn is passed through an annealing furnace 21 installed below a drawing furnace 11, whereby the cooling rate of the glass fiber is restrained as compared with the case where it is cooled by air.
    Type: Application
    Filed: July 13, 2011
    Publication date: January 19, 2012
    Applicant: SUMITOMO ELECTRIC INDUSTRIES, LTD.
    Inventors: Tetsuya HARUNA, Masaaki Hirano, Nobuhiro Hikichi
  • Patent number: 8023181
    Abstract: Provided is an optical fiber for amplification and an optical fiber amplifier for use in L-band, in which optical fiber the increase of transmission loss and the degradation of hydrogen-resistant characteristic can be restrained. The optical fiber is basically made of silica glass and comprises: a core region doped with erbium and P element of 2 wt % to 5 wt % concentration, Ge not being added thereto; and a cladding region enclosing the core region and doped with F element, wherein the optical fiber has a gain at least in a wavelength range of 1570 to 1620 nm. The optical fiber amplifier comprises: the optical fiber; a pump light source for outputting the pump light capable of exciting a rare-earth element added to the core region of the optical fiber; and an optical coupler for introducing into the optical fiber the pump light having been output from the pump light source.
    Type: Grant
    Filed: January 16, 2008
    Date of Patent: September 20, 2011
    Assignee: Sumitomo Electric Industries, Ltd.
    Inventor: Tetsuya Haruna
  • Patent number: 7940815
    Abstract: The present invention relates to fluorescent glass which is easily put into practical use, and optical elements including the same. In one aspect, the fluorescent glass is comprised of silica-based glass containing Bi as a dopant, and adapted to generate fluorescence in response to pumping light in a wavelength band of 980 nm incident thereon. In another aspect, the fluorescent glass contains at least one species of transition metal as a dopant, and exhibits a 980-nm band absorption spectrum having a full width at half maximum exceeding 10 nm. In still another aspect, the fluorescent glass is comprised of silica-based glass containing at least one species of transition element as a dopant, and exhibits a fluorescence spectrum with a peak intensity fluctuating within a range of ?1 dB or more but 1 dB or less with respect to pumping light having a fixed intensity in a state set to a temperature of ?5° C. or more but 65° C. or less.
    Type: Grant
    Filed: July 19, 2006
    Date of Patent: May 10, 2011
    Assignees: Sumitomo Electric Industries, Ltd., Kyushu University, National University Corporation
    Inventors: Motoki Kakui, Tetsuya Haruna, Takahiro Murata
  • Publication number: 20110085768
    Abstract: An optical fiber having excellent strength that can be manufactured at low cost, as well as a method for making such optical fiber, is provided. An optical fiber 1 is a silica-based optical fiber comprising a core 11, an optical cladding 12 surrounding the core 11, and a jacketing region 13 surrounding the optical cladding 12 and having a uniform composition throughout from the internal circumference to the outer circumference. A compressive strained layer having a residual compressive stress is provided at the outermost circumference of the jacketing region 13.
    Type: Application
    Filed: October 13, 2010
    Publication date: April 14, 2011
    Applicant: SUMITOMO ELECTRIC INDUSTRIES, LTD.
    Inventors: Tetsuya Nakanishi, Masaaki Hirano, Tetsuya Haruna, Maki Ikechi
  • Patent number: 7894697
    Abstract: The present invention relates to an optical fiber which has a structure for further increasing an FOM (=|dispersion|/loss) and which can be applied to a dispersion compensation module. The optical fiber is mainly composed of silica glass and has a core region including a center of an optical axis, a depressed region surrounding the core region, a ring region surrounding the depressed region, and a cladding region surrounding the ring region and doped with F. As compared with the refractive index of pure silica glass, a relative refractive index difference of the core region is greater than 2% but less than 3%, a relative refractive index difference of the depressed region is ?1% or more but ?0.5% or less, a relative refractive index difference of the ring region is 0.01% or more but 0.24% or less, and a relative refractive index difference of the cladding region is ?0.3% or more but ?0.1% or less. The FOM at the wavelength of 1550 nm is 250 ps/nm/dB or more.
    Type: Grant
    Filed: October 22, 2007
    Date of Patent: February 22, 2011
    Assignee: Sumitomo Electric Industries, Ltd.
    Inventors: Takashi Sasaki, Kazumasa Makihara, Tetsuya Haruna, Masashi Onishi, Masaaki Hirano
  • Publication number: 20100284658
    Abstract: The present invention relates to an optical fiber which has a structure for further increasing an FOM (=|dispersion|/loss) and which can be applied to a dispersion compensation module. The optical fiber is mainly composed of silica glass and has a core region including a center of an optical axis, a depressed region surrounding the core region, a ring region surrounding the depressed region, and a cladding region surrounding the ring region and doped with F. As compared with the refractive index of pure silica glass, a relative refractive index difference of the core region is greater than 2% but less than 3%, a relative refractive index difference of the depressed region is ?1% or more but ?0.5% or less, a relative refractive index difference of the ring region is 0.01% or more but 0.24% or less, and a relative refractive index difference of the cladding region is ?0.3% or more but ?0.1% or less. The FOM at the wavelength of 1550 nm is 250 ps/nm/dB or more.
    Type: Application
    Filed: October 22, 2007
    Publication date: November 11, 2010
    Inventors: Takashi Sasaki, Kazumasa Makihara, Tetsuya Haruna, Masashi Onishi, Masaaki Hirano
  • Patent number: 7822307
    Abstract: When a glass fiber and an inner fiber coating layer are to be attached to a connector by removing an outer fiber coating layer while leaving the inner fiber coating layer as it is, a collective coating and the outer fiber coating layer can be removed at a stretch so that the inner fiber coating layer can easily and satisfactorily be exposed. In the ultraviolet curable resin coating layer of a coated optical fiber 17 of an optical fiber ribbon 11 for wiring of equipment, the inner fiber coating layer 15 has a Young's modulus of 600 MPa to 1000 MPa, and the outer fiber coating layer 16 has a Young's modulus of 10 MPa to 300 MPa. The material of the outer fiber coating layer 16 is made by mixing 100 weight parts of base resin, 1-30 weight parts of silicone-based additive, and 0.5 to 40 weight parts of long chain fatty acid ester compound, wherein the base resin is a material made of a urethane metha acrylate oligomer, a mono-functional or multi-functional reactive dilution monomer, and an optical initiator.
    Type: Grant
    Filed: April 7, 2009
    Date of Patent: October 26, 2010
    Assignee: Sumitomo Electric Industries, Ltd.
    Inventors: Kazunori Tanaka, Kazumasa Oishi, Tomoyuki Hattori, Tetsuya Haruna, Wataru Sakurai, Mitsuaki Tamura, Kazuto Saito
  • Publication number: 20100254658
    Abstract: When a glass fiber and an inner fiber coating layer are to be attached to a connector by removing an outer fiber coating layer while leaving the inner fiber coating layer as it is, a collective coating and the outer fiber coating layer can be removed at a stretch so that the inner fiber coating layer can easily and satisfactorily be exposed. In the ultraviolet curable resin coating layer of a coated optical fiber 17 of an optical fiber ribbon 11 for wiring of equipment, the inner fiber coating layer 15 has a Young's modulus of 600 MPa to 1000 MPa, and the outer fiber coating layer 16 has a Young's modulus of 10 MPa to 300 MPa. The material of the outer fiber coating layer 16 is made by mixing 100 weight parts of base resin, 1-30 weight parts of silicone-based additive, and 0.5 to 40 weight parts of long chain fatty acid ester compound, wherein the base resin is a material made of a urethane metha acrylate oligomer, a mono-functional or multi-functional reactive dilution monomer, and an optical initiator.
    Type: Application
    Filed: April 7, 2009
    Publication date: October 7, 2010
    Inventors: Kazunori Tanaka, Kazumasa Oishi, Tomoyuki Hattori, Tetsuya Haruna, Wataru Sakurai, Mitsuaki Tamura, Kazuto Saito
  • Publication number: 20100071420
    Abstract: The present invention relates to an optical fiber preform fabricating method that makes it possible to implement a reduction in iron impurities at a low cost. The optical fiber preform fabricating method comprises a glass synthesis step for forming a glass region constituting at least a part of the core area of the optical fiber. The glass synthesis step includes a deposition step of depositing glass particles containing the Al-element inside the glass pipe by means of chemical vapor deposition, and a consolidation step of obtaining a transparent glass body from the glass soot body thus obtained. In other words, the deposition step synthesizes glass particles on the inside wall of a glass pipe by feeding raw material gas, in which the content ratio (O/Al) of the O-element and Al-element is 20 or less, into the glass pipe. Furthermore, the consolidation step obtains a transparent glass body from the glass soot body by heating the glass soot body.
    Type: Application
    Filed: June 21, 2007
    Publication date: March 25, 2010
    Applicant: SUMITOMO ELECTRIC INDUSTRIES, LTD.
    Inventors: Tetsuya Nakanishi, Tetsuya Haruna, Shinji Ishikawa
  • Patent number: 7586673
    Abstract: The present invention relates to an optical gain waveguide having excellent gain flatness in C-band, and excellent tolerance against variations of a pumping light wavelength as well, and a method of controlling the same. The optical gain waveguide includes an optical waveguide region which is doped with Er element which can be pumped by irradiating pumping light with a wavelength of 976 nm or less, or a wavelength of 981 nm or more. A population inversion of Er is optimized so that a gain variation in the C-band becomes minimum, by the irradiation of the pumping light. At this time, a relative gain variation of the optical gain waveguide, which is defined by a peak gain value and a minimum gain value in the wavelength region of 1,530 nm to 1,560 nm becomes smaller than 11.5%. In addition, in the optical gain waveguide, a width of wavelength range producing the relative gain variation smaller than 11% is 36 nm or more.
    Type: Grant
    Filed: March 2, 2006
    Date of Patent: September 8, 2009
    Assignees: Sumitomo Electric Industries, Ltd., Kyushu University, National University Corporation
    Inventors: Takahiro Murata, Motoki Kakui, Tetsuya Haruna
  • Publication number: 20090185263
    Abstract: Provided is an erbium doped optical fiber (EDF) for amplification which allows an easy estimation of the amplification performance and high production stability. The fiber includes a core and a cladding. The core is mainly made of silica glass and doped with erbium at a concentration of 500 wtppm or more and 2500 wtppm or less. In the fiber, the cutoff wavelength is 850 nm or more and 1450 nm or less, the mode field diameter is 4.5 ?m or more and 6.5 ?m or less, the polarization mode dispersion is not more than 0.1 ps per 10 m, the coordination number of oxygen elements around an erbium element in the core is one or more and eight or less, and the bond length between erbium and oxygen is 0.225 nm or more and 0.235 or less.
    Type: Application
    Filed: December 27, 2006
    Publication date: July 23, 2009
    Applicants: MITSUBISHI ELECTRIC CORPORATION, SUMITOMO ELECTRIC INDUSTRIES, LTD.
    Inventors: Tetsuya Haruna, Junji Iihara, Masashi Onishi, Shinji Ishikawa
  • Publication number: 20090180174
    Abstract: A first step, in which P2O5-containing glass is deposited inside a silica glass pipe, and a second step, in which a Cl2-containing gas is introduced into the pipe and the P2O5-containing glass is dehydrated by heating the pipe, are repeated alternately. A third step, in which glass that does not contain P2O5 is deposited on the inside of the silica glass pipe, may further be provided such that the first step, the second step, and the third step are repeatedly performed in this order. A rare-earth-doped optical fiber, which has a attenuation of 15 dB/km or less at a wavelength of 1200 nm, comprises a core region and a cladding region enclosing the core region, wherein the core region includes phosphorus of 3 wt % or more, aluminum of 0.3 wt % or more, a rare-earth element of 500 wtppm or more, and chlorine of 0.03 wt % or more, and the cladding region has a refractive index that is lower than the refractive index of the core region.
    Type: Application
    Filed: January 12, 2009
    Publication date: July 16, 2009
    Inventors: Tetsuya Haruna, Manabu Ishikawa
  • Publication number: 20090133445
    Abstract: A method for manufacturing a glass body containing bismuth, which can be used for manufacturing an optical fiber having a low background-loss is provided. The method includes depositing a glass micro-particle layer on an inner wall of a glass pipe, consolidating the glass micro-particle layer to form a glass layer, reducing of a diameter of the glass pipe having the glass layer on the inner wall of the glass pipe, and collapsing the glass pipe having been reduced in diameter at the diameter-reducing step so as to form the glass body. At the depositing step, the glass micro-particle layer is formed while an organobismuth compound is being supplied into the glass pipe. At the consolidating step, the glass layer is consolidated while an organobismuth compound is being supplied into the glass pipe. The optical fiber is made by drawing the glass body.
    Type: Application
    Filed: August 29, 2006
    Publication date: May 28, 2009
    Inventors: Tetsuya Haruna, Toshiki Taru, Motoki Kakui, Masashi Onishi
  • Publication number: 20090103171
    Abstract: Provided is an optical fiber for amplification and an optical fiber amplifier for use in L-band, in which optical fiber the increase of transmission loss and the degradation of hydrogen-resistant characteristic can be restrained. The optical fiber is basically made of silica glass and comprises: a core region doped with erbium and P element of 2 wt % to 5 wt % concentration, Ge not being added thereto; and a cladding region enclosing the core region and doped with F element, wherein the optical fiber has a gain at least in a wavelength range of 1570 to 1620 nm. The optical fiber amplifier comprises: the optical fiber; a pump light source for outputting the pump light capable of exciting a rare-earth element added to the core region of the optical fiber; and an optical coupler for introducing into the optical fiber the pump light having been output from the pump light source.
    Type: Application
    Filed: January 16, 2008
    Publication date: April 23, 2009
    Inventor: Tetsuya Haruna
  • Publication number: 20090078870
    Abstract: The present invention relates to a long-life, low-power consumption infrared imaging system having a structure for realizing with a high reliability both the taking of an image of its surrounding environments and the detection of objects. The infrared imaging system comprises a light source section, an image pickup section, a processing section, and a monitor. For emitting SC light including a wavelength component in a near-infrared wavelength band as irradiation light, the light source section includes a seed light source emitting laser light, an optical fiber generating the SC light in response to the input of the laser light, and wavelength selecting means. The wavelength selecting means selectively limits the wavelength region of the irradiation light in accordance with imaging modes.
    Type: Application
    Filed: January 19, 2007
    Publication date: March 26, 2009
    Inventor: Tetsuya Haruna
  • Patent number: 7436583
    Abstract: The present invention relates to an optical amplification fiber and others capable of effectively reducing nonlinear interaction between signal channels even in transmission of multiplexed signal light containing multiple signal channels arranged in high density and also effectively reducing bending loss. An optical amplification module has an optical isolator, a WDM coupler, an Er-doped optical fiber (EDF) as an optical amplification fiber, a WDM coupler, and an optical isolator, which are arranged in order on a signal light propagation path from an input connector to an output connector, and further has a pumping light source connected to the WDM coupler and a pumping light source connected to the other WDM coupler. The EDF, at the wavelength of 1607 nm, has a mode field diameter (MFD) of 10 ?m or more to the fundamental mode and a MAC number (=MFD/cutoff wavelength) of 6.8 or less to the fundamental mode.
    Type: Grant
    Filed: September 3, 2004
    Date of Patent: October 14, 2008
    Assignee: Sumitomo Electric Industries, Ltd.
    Inventors: Motoki Kakui, Tetsuya Haruna, Shinji Ishikawa
  • Publication number: 20080212091
    Abstract: A light source unit and a spectrum analyzer are provided in which the influence of interference can be reduced under conditions where light is separated into spectral components. A spectrum analyzer 1 is equipped with a light source unit 2 for irradiating light onto sample A, a detector unit 3 for detecting the light reflected, scattered, or transmitted from the sample A, and a sample stage 4 on which a sample A is placed. A wide band light source 20 generates wide band light P1 such as supercontinuum light (SC light). Also, the light source unit 2 has an interference suppressing means for suppressing the interference of each wavelength component of the wide band light P1.
    Type: Application
    Filed: January 22, 2008
    Publication date: September 4, 2008
    Applicant: Sumitomo Electric Industries, Ltd.
    Inventors: Masato Tanaka, Tetsuya Nakanishi, Tetsuya Haruna, Masaaki Hirano, Toshiaki Okuno, Takashi Sasaki, Masashi Onishi
  • Patent number: 7286740
    Abstract: The present invention relates to an optical fiber which has a structure for further increasing an FOM (=|dispersion|/loss) and which can be applied to a dispersion compensation module. The optical fiber is mainly composed of silica glass and has a core region including a center of an optical axis, a depressed region surrounding the core region, a ring region surrounding the depressed region, and a cladding region surrounding the ring region and doped with F. As compared with the refractive index of pure silica glass, a relative refractive index difference of the core region is 3% or more but 4% or less, a relative refractive index difference of the depressed region is ?1% or more but ?0.5% or less, a relative refractive index difference of the ring region is 0.01% or more but 0.24% or less, and a relative refractive index difference of the cladding region is ?0.3% or more but ?0.1% or less. The FOM at the wavelength of 1550 nm is 250 ps/nm/dB or more.
    Type: Grant
    Filed: October 6, 2006
    Date of Patent: October 23, 2007
    Assignee: Sumitomo Electric Industries, Ltd.
    Inventors: Takashi Sasaki, Kazumasa Makihara, Tetsuya Haruna, Masashi Onishi, Masaaki Hirano
  • Publication number: 20070217754
    Abstract: The present invention relates to an optical fiber which has a structure for further increasing an FOM (=|dispersion|/loss) and which can be applied to a dispersion compensation module. The optical fiber is mainly composed of silica glass and has a core region including a center of an optical axis, a depressed region surrounding the core region, a ring region surrounding the depressed region, and a cladding region surrounding the ring region and doped with F. As compared with the refractive index of pure silica glass, a relative refractive index difference of the core region is 3% or more but 4% or less, a relative refractive index difference of the depressed region is ?1% or more but ?0.5% or less, a relative refractive index difference of the ring region is 0.01% or more but 0.24% or less, and a relative refractive index difference of the cladding region is ?0.3% or more but ?0.1% or less. The FOM at the wavelength of 1550 nm is 250 ps/nm/dB or more.
    Type: Application
    Filed: October 6, 2006
    Publication date: September 20, 2007
    Inventors: Takashi Sasaki, Kazumasa Makihara, Tetsuya Haruna, Masashi Onishi, Masaaki Hirano
  • Publication number: 20070036509
    Abstract: The present invention relates to fluorescent glass which is easily put into practical use, and optical elements including the same. In one aspect, the fluorescent glass is comprised of silica-based glass containing Bi as a dopant, and adapted to generate fluorescence in response to pumping light in a wavelength band of 980 nm incident thereon. In another aspect, the fluorescent glass contains at least one species of transition metal as a dopant, and exhibits a 980-nm band absorption spectrum having a full width at half maximum exceeding 10 nm. In still another aspect, the fluorescent glass is comprised of silica-based glass containing at least one species of transition element as a dopant, and exhibits a fluorescence spectrum with a peak intensity fluctuating within a range of ?1 dB or more but 1 dB or less with respect to pumping light having a fixed intensity in a state set to a temperature of ?5° C. or more but 65° C. or less.
    Type: Application
    Filed: July 19, 2006
    Publication date: February 15, 2007
    Inventors: Motoki Kakui, Tetsuya Haruna, Takahiro Murata