Patents by Inventor Yasushi Koyano
Yasushi Koyano 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: 7874725Abstract: An optical fiber temperature distribution measuring apparatus and a method for measuring optical fiber temperature distribution, provided with a light source for inputting a pulse light to an optical fiber to be measured, a signal detecting unit for detecting a received light intensity of a predetermined light included in a backscattering light generated by an input of the pulse light in the optical fiber to be measured, and a signal processing unit for calculating a value corresponding to a variation of the received light intensity due to a hydrogen molecular absorption of the optical fiber to be measured based on the received light intensity of the predetermined light, to compensate the received light intensity of the predetermined light corresponding to a temperature of the optical fiber to be measured based on the value.Type: GrantFiled: September 21, 2007Date of Patent: January 25, 2011Assignees: J-Power Systems Corporation, Sumitomo Electric Industries, Ltd.Inventors: Hidehiko Komeda, Tsuyoshi Igi, Yasushi Koyano, Fumiyoshi Ohkubo, Kazuaki Negishi
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Patent number: 7773847Abstract: A core part of a multimode optical fiber including the core part and a cladding part has a structure composed of a plurality of concentric layers in which a refractive index is decreased stepwise from a first core layer as an innermost layer to a third core layer as an outermost layer. The structure having the plurality of layers is formed by adjusting a quantity of addition of fluorine to silica glass. Fluorine is added to the cladding part so that a refractive index is lower than that of the third core layer as the outermost layer of the core part.Type: GrantFiled: April 28, 2006Date of Patent: August 10, 2010Assignee: Sumitomo Electric Industries, Ltd.Inventors: Kazuaki Negishi, Yasushi Koyano, Itaru Sakabe, Masahiko Matsui, Masashi Onishi, Tetsuya Nakanishi
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Publication number: 20100111486Abstract: The present invention relates to a dispersion compensating module having a configuration that can effectively suppress high-speed fluctuations in the polarization state of light even when being imparted with impact or vibration. In the dispersion compensating module, a dispersion compensating optical fiber is fixed while being wound around the barrel of a bobbin, and the bobbin is fixed in the inside of a housing via a buffer that absorbs impact or vibration. The bobbin corresponds to a holder holding the dispersion compensating optical fiber fixed in a state of coil. The housing corresponds to a struct fixing the holder. The buffer fills a space between the housing and the bobbin on which the dispersion compensating optical fiber is coiled.Type: ApplicationFiled: November 3, 2009Publication date: May 6, 2010Applicant: Sumitomo Electric Industries, Ltd.Inventors: Tetsuya HAYASHI, Eisuke SASAOKA, Kazuya KUWAHARA, Takashi SASAKI, Yasushi KOYANO, Fumiyoshi OHKUBO, Shinjiro HAGIHARA
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Publication number: 20090059996Abstract: An optical fiber temperature distribution measuring apparatus and a method for measuring optical fiber temperature distribution, provided with a light source for inputting a pulse light to an optical fiber to be measured, a signal detecting unit for detecting a received light intensity of a predetermined light included in a backscattering light generated by an input of the pulse light in the optical fiber to be measured, and a signal processing unit for calculating a value corresponding to a variation of the received light intensity due to a hydrogen molecular absorption of the optical fiber to be measured based on the received light intensity of the predetermined light, to compensate the received light intensity of the predetermined light corresponding to a temperature of the optical fiber to be measured based on the value.Type: ApplicationFiled: September 21, 2007Publication date: March 5, 2009Inventors: Hidehiko Komeda, Tsuyoshi Igi, Yasushi Koyano, Fumiyoshi Ohkubo, Kazuaki Negishi
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Patent number: 7379646Abstract: The present invention relates to an optical fiber product suitable for fabricating an optical cable that requires a complicated length adjustment. The optical fiber product includes an effective use portion used as the optical cable, surplus portions connected to both ends of the effective use portion, and a distinguishing structure clearly indicating boundary portions between the effective use portion and the surplus portions. With the above structure, the surplus portions that become finally unnecessary are surely cut off in a fabrication step of the optical cable, thus enabling collect use of only effective use portion as the optical cable.Type: GrantFiled: October 12, 2004Date of Patent: May 27, 2008Assignee: Sumitomo Electric Industries, Ltd.Inventors: Yasushi Koyano, Hiroyoshi Yamamoto, Yasuhiro Naganuma
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Publication number: 20060263019Abstract: A core part of a multimode optical fiber including the core part and a cladding part has a structure composed of a plurality of concentric layers in which a refractive index is decreased stepwise from a first core layer as an innermost layer to a third core layer as an outermost layer. The structure having the plurality of layers is formed by adjusting a quantity of addition of fluorine to silica glass. Fluorine is added to the cladding part so that a refractive index is lower than that of the third core layer as the outermost layer of the core part.Type: ApplicationFiled: April 28, 2006Publication date: November 23, 2006Inventors: Kazuaki Negishi, Yasushi Koyano, Itaru Sakabe, Masahiko Matsui, Masashi Onishi, Tetsuya Nakanishi
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Patent number: 7043131Abstract: After a wide-band DCF is wound around a bobbin to form an optical fiber coil 32, the latter is removed from the bobbin and placed into a bundle state (the state where the increase in transmission loss in the wavelength band of 1.55 ?m caused by distortions in winding is reduced by 0.1 dB/km or more) released from distortions in winding. A resin 42 is used as a coil-tidying member so as to secure the optical fiber coil 32 to a storage case 40 at four positions. Both ends of the optical fiber coil 32 are connected to pigtail fibers at fusion-splicing parts 44, respectively. Even when the storage case 40 is closed with a lid after the optical fiber coil 32 is secured to the storage case 40 with the resin 42, there remain interstices within the bundle of the optical fiber coil 32 and a space between the optical fiber coil 32 and the storage case 40. As a result, even when the optical fiber coil 32 in a bundle state is accommodated in the storage case 40, transmission loss and the like would not increase.Type: GrantFiled: August 14, 2002Date of Patent: May 9, 2006Assignee: Sumitomo Electric Industries, Ltd.Inventors: Yasushi Koyano, Eisuke Sasaoka, Shigeru Tanaka, Kohei Kobayashi, Masashi Onishi, Kenji Tamano, Takashi Fujii
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Publication number: 20060018610Abstract: The present invention relates to an optical fiber product suitable for fabricating an optical cable that requires a complicated length adjustment. The optical fiber product includes an effective use portion used as the optical cable, surplus portions connected to both ends of the effective use portion, and a distinguishing structure clearly indicating boundary portions between the effective use portion and the surplus portions. With the above structure, the surplus portions that become finally unnecessary are surely cut off in a fabrication step of the optical cable, thus enabling collect use of only effective use portion as the optical cable.Type: ApplicationFiled: October 12, 2004Publication date: January 26, 2006Inventors: Yasushi Koyano, Hiroyoshi Yamamoto, Yasuhiro Naganuma
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Publication number: 20040013395Abstract: After a wide-band DCF is wound around a bobbin to form an optical fiber coil 32, the latter is removed from the bobbin and placed into a bundle state (the state where the increase in transmission loss in the wavelength band of 1.55 &mgr;m caused by distortions in winding is reduced by 0.1 dB/km or more) released from distortions in winding. A resin 42 is used as a coil-tidying member so as to secure the optical fiber coil 32 to a storage case 40 at four positions. Both ends of the optical fiber coil 32 are connected to pigtail fibers at fusion-splicing parts 44, respectively. Even when the storage case 40 is closed with a lid after the optical fiber coil 32 is secured to the storage case 40 with the resin 42, there remain interstices within the bundle of the optical fiber coil 32 and a space between the optical fiber coil 32 and the storage case 40. As a result, even when the optical fiber coil 32 in a bundle state is accommodated in the storage case 40, transmission loss and the like would not increase.Type: ApplicationFiled: August 14, 2002Publication date: January 22, 2004Inventors: Yasushi Koyano, Eisuke Sasaoka, Shigeru Tanaka, Kohei Kobayashi, Masashi Onishi, Kenji Tamano, Takashi Fujii
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Patent number: 6650821Abstract: After a wide-band DCF is wound around a bobbin to form an optical fiber coil 32, the latter is removed from the bobbin and placed into a bundle state (the state where the increase in transmission loss in the wavelength band of 1.55 &mgr;m caused by distortions in winding is reduced by 0.1 dB/km or more) released from distortions in winding. A resin 42 is used as a coil-tidying member so as to secure the optical fiber coil 32 to a storage case 40 at four positions. Both ends of the optical fiber coil 32 are connected to pigtail fibers at fusion-splicing parts 44, respectively. Even when the storage case 40 is closed with a lid after the optical fiber coil 32 is secured to the storage case 40 with the resin 42, there remain interstices within the bundle of the optical fiber coil 32 and a space between the optical fiber coil 32 and the storage case 40. As a result, even when the optical fiber coil 32 in a bundle state is accommodated in the storage case 40, transmission loss and the like would not increase.Type: GrantFiled: January 4, 2000Date of Patent: November 18, 2003Assignee: Sumitomo Electric Industries, Ltd.Inventors: Yasushi Koyano, Eisuke Sasaoka, Shigeru Tanaka, Kohei Kobayashi, Masashi Onishi, Kenji Tamano, Takashi Fujii
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Publication number: 20030142938Abstract: After a wide-band DCF is wound around a bobbin to form an optical fiber coil 32, the latter is removed from the bobbin and placed into a bundle state (the state where the increase in transmission loss in the wavelength band of 1.55 &mgr;m caused by distortions in winding is reduced by 0.1 dB/km or more) released from distortions in winding. A resin 42 is used as a coil-tidying member so as to secure the optical fiber coil 32 to a storage case 40 at four positions. Both ends of the optical fiber coil 32 are connected to pigtail fibers at fusion-splicing parts 44, respectively. Even when the storage case 40 is closed with a lid after the optical fiber coil 32 is secured to the storage case 40 with the resin 42, there remain interstices within the bundle of the optical fiber coil 32 and a space between the optical fiber coil 32 and the storage case 40. As a result, even when the optical fiber coil 32 in a bundle state is accommodated in the storage case 40, transmission loss and the like would not increase.Type: ApplicationFiled: February 10, 2003Publication date: July 31, 2003Applicant: SUMITOMO ELECTRIC INDUSTRIES, LTD.Inventors: Yasushi Koyano, Eisuke Sasaoka, Shigeru Tanaka, Kohei Kobayashi, Masashi Onishi
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Patent number: 6546180Abstract: After a wide-band DCF is wound around a bobbin to form an optical fiber coil 32, the latter is removed from the bobbin and placed into a bundle state (the state where the increase in transmission loss in the wavelength band of 1.55 &mgr;m caused by distortions in winding is reduced by 0.1 dB/km or more) released from distortions in winding. A resin 42 is used as a coil-tidying member so as to secure the optical fiber coil 32 to a storage case 40 at four positions. Both ends of the optical fiber coil 32 are connected to pigtail fibers at fusion-splicing parts 44; respectively. Even when the storage case 40 is closed with a lid after the optical fiber coil 32 is secured to the storage case 40 with the resin 42, there remain interstices within the bundle of the optical fiber coil 32 and a space between the optical fiber coil 32 and the storage case 40. As a result, even when the optical fiber coil 32 in a bundle state is accommodated in the storage case 40, transmission loss and the like would not increase.Type: GrantFiled: February 2, 1999Date of Patent: April 8, 2003Assignee: Sumitomo Electric Industries, Ltd.Inventors: Yasushi Koyano, Eisuke Sasaoka, Shigeru Tanaka, Kohei Kobayashi, Masashi Onishi
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Patent number: 6055081Abstract: In a chromatic dispersion compensator, an optical signal directing unit such as an optical circulator or a directional coupler having a first, second, third and fourth ports. The optical signal directing unit directs an optical signal inputted from one of the ports to another port of the ports. A reflection-type compensator including a dispersion compensating fiber, a reflecting portion and changing unit for changing a polarization direction of a reciprocating signal light, in which the dispersion compensating fiber is connected to the reflecting portion via the changing unit. An input transmission path which is connected to the first port; and an output transmission path which is connected to the fourth port so that the signal light is outputted from the fourth port. The reflection-type compensating unit is connected to one of the second and third ports, and the chirped grating is connected to the other port.Type: GrantFiled: January 10, 1997Date of Patent: April 25, 2000Assignee: Sumitomo Electric Industries, Ltd.Inventors: Yasushi Koyano, Masayuki Shigematsu
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Patent number: 5838867Abstract: The present invention relates to a dispersion compensating fiber for improving a transmission system with it in total chromatic dispersion and dispersion slope in the 1.55 .mu.m wavelength band. The dispersion compensating fiber according to the present invention is characterized by having the following characteristics for light in the 1.55 .mu.m wavelength band: chromatic dispersion not less than -40 ps/km/nm and not more than 0 ps/km/nm; dispersion slope not less than -0.5 ps/km/nm.sup.2 and not more than -0.1 ps/km/nm.sup.2 ; transmission loss not more than 0.5 dB/km; polarization mode dispersion not more than 0.7 ps.multidot.km.sup.-1/2 ; mode field diameter not less than 4.5 .mu.m and not more than 6.5 .mu.m; cut-off wavelength not less than 0.7 .mu.m and not more than 1.7 .mu.m in the length of 2 m; and bending loss at the diameter of 20 mm, not more than 100 dB/m.Type: GrantFiled: April 15, 1997Date of Patent: November 17, 1998Assignee: Sumitomo Electric Industries, Ltd.Inventors: Masashi Onishi, Hiroo Kanamori, Masayuki Nishimura, Tomonori Kashiwada, Yasushi Koyano
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Patent number: 5701188Abstract: A chromatic dispersion compensator includes an optical circulator or a directional coupler having a first, second and third ports; an input transmission path connected to the first port; an output transmission path connected to the third port; a chirped grating connected to the second port; and a dispersion compensating fiber connected to at least one of the first, second and third ports. The dispersion compensating fiber and the chirped grating have chromatic dispersion characteristics which are opposite to the chromatic dispersion characteristics of the input and output transmission paths. In the wavelength compensator, the optical signal is incident into the first port from the input transmission path, and is made to go out to the chirped grating from the second port. Further, the optical signal is incident from the chirped grating to return to the second port, and is made to go to the output transmission path from the third port.Type: GrantFiled: September 28, 1995Date of Patent: December 23, 1997Assignee: Sumitomo Electric Industries, Ltd.Inventors: Masayuki Shigematsu, Yasushi Koyano
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Patent number: RE38086Abstract: The present invention relates to a dispersion compensating fiber for improving a transmission system with it in total chromatic dispersion and dispersion slope in the 1.55 &mgr;m wavelength band. The dispersion compensating fiber according to the present invention is characterized by having the following characteristics for light in the 1.55 &mgr;m wavelength band: chromatic dispersion not less than −40 ps/km/nm and not more than 0 ps/km/nm; dispersion slope not less than −0.5 ps/km/nm2 and not more than −0.1 ps/km/nm2; transmission loss not more than 0.5 dB/km; polarization mode dispersion not more than 0.7 ps.km−½; mode field diameter not less than 4.5 &mgr;m and not more than 6.5 &mgr;m; cut-off wavelength not less than 0.7 &mgr;m and not more than 1.7 &mgr;m in the length of 2 m; and bending loss at the diameter of 20 mm, not more than 100 dB/m.Type: GrantFiled: November 17, 2000Date of Patent: April 22, 2003Assignee: Sumitomo Electric Industries, Ltd.Inventors: Masashi Onishi, Hiroo Kanamori, Masayuki Nishimura, Tomonori Kashiwada, Yasushi Koyano