Patents by Inventor Junichi Kani
Junichi Kani 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).
-
Patent number: 7555215Abstract: A dual structure for a multiplexing section extended to an OSU is obtained without adding a dynamic function, such as an optical switch, to a W-MULDEM. The W-MULDEM of an optical wavelength division multiplexing access system divides, among ports corresponding to the individual ONUs, downstream optical signals having wavelengths ?d1 to ?dn, which are received along a current-use optical fiber, or downstream optical signals having wavelengths ?d1+?? to ?dn+??, which are received along a redundant optical fiber. The W-MULDEM also multiplexes, for the port that corresponds to the current-use optical fiber or the redundant optical fiber, upstream optical signals having wavelengths ?u1 to ?un or wavelengths ?u1+?? to ?un+??, which are received along optical fibers corresponding to the ONUs. A wavelength difference between the downstream optical signal and the upstream optical signal that are consonant with each ONU is defined as an integer times the FSR of an AWG.Type: GrantFiled: May 28, 2004Date of Patent: June 30, 2009Assignee: Nippon Telegraph and Telephone CorporationInventors: Hirotaka Nakamura, Junichi Kani, Hiroo Suzuki, Mitsuhiro Teshima, Ukyo Yamaguchi, Hidetaka Onishi, Katsumi Iwatsuki
-
Patent number: 7474460Abstract: An optical modulation apparatus is provided which implements a stable amplifying function by reducing the effect of reflected light rays from end faces of a bidirectional optical amplifier by imposing a numerical limitation on the relationship between the gain of the bidirectional optical amplifier and the loss of the optical modulator, or by inserting a polarization rotation section in a reflection type optical modulator including the bidirectional optical amplifier or in a multi-wavelength collective optical modulation system combining the multiple optical modulators. An optical modulation apparatus is provided which implements a stable amplifying function and cost reduction by reducing the effect of reflected light rays by interposing optical isolators at every alternate SOAs in a transmission-type optical modulation apparatus including a plurality of semiconductor optical amplifiers (SOAs) connected in a multistage fashion.Type: GrantFiled: February 13, 2007Date of Patent: January 6, 2009Assignee: Nippon Telegraph and Telephone Corporation.Inventors: Masamichi Fujiwara, Junichi Kani, Koji Akimoto, Katsumi Iwatsuki
-
Patent number: 7336414Abstract: An optical modulation apparatus is provided which implements a stable amplifying function by reducing the effect of reflected light rays form end faces of a bidirectional optical amplifier by imposing a numerical limitation on the relationship between the gain of the bidirectional optical amplifier and the loss of the optical modulator, or by inserting a polarization rotation section in a reflection type optical modulator including the bidirectional optical amplifier or in a multi-wavelength collective optical modulation system combining the multiple optical modulators. An optical modulation apparatus is provided which implements a stable amplifying function and cost reduction by reducing the effect of reflected light rays by interposing optical isolators at every alternate SOAs in a transmission-type optical modulation apparatus including a plurality of semiconductor optical amplifiers (SOAs) connected in a multistage fashion.Type: GrantFiled: June 16, 2004Date of Patent: February 26, 2008Assignee: Nippon Telegraph and Telephone CorporationInventors: Masamichi Fujiwara, Junichi Kani, Koji Akimoto, Katsumi Iwatsuki
-
Publication number: 20070127113Abstract: An optical modulation apparatus is provided which implements a stable amplifying function by reducing the effect of reflected light rays from end faces of a bidirectional optical amplifier by imposing a numerical limitation on the relationship between the gain of the bidirectional optical amplifier and the loss of the optical modulator, or by inserting a polarization rotation section in a reflection type optical modulator including the bidirectional optical amplifier or in a multi-wavelength collective optical modulation system combining the multiple optical modulators. An optical modulation apparatus is provided which implements a stable amplifying function and cost reduction by reducing the effect of reflected light rays by interposing optical isolators at every alternate SOAs in a transmission-type optical modulation apparatus including a plurality of semiconductor optical amplifiers (SOAs) connected in a multistage fashion.Type: ApplicationFiled: February 13, 2007Publication date: June 7, 2007Applicant: Nippon Telegraph and Telephone CorporationInventors: Masamichi Fujiwara, Junichi Kani, Koji Akimoto, Katsumi Iwatsuki
-
Patent number: 7068412Abstract: With respect to the relative intensity noise (RIN) for inputs to an optical modulator or the signal-to-noise ratio (SNR) for outputs therefrom, the optical modulator modulating coherent lights of different wavelengths obtained by slicing a spectrum of the multi-wavelength light, the shape of a spectrum of a multi-wavelength light is controlled so that predetermined RIN and SNR can be obtained in accordance with transmission system parameters (the type and distance of optical fibers, the number of repeaters), thus enabling design meeting a performance specification for a conventional transmission section using semiconductor lasers.Type: GrantFiled: April 16, 2004Date of Patent: June 27, 2006Assignee: Nippon Telegraph and Telephone Corp.Inventors: Masamichi Fujiwara, Katsuhiro Araya, Mitsuhiro Teshima, Junichi Kani, Kenichi Suzuki
-
Publication number: 20060062576Abstract: A dual structure for a multiplexing section extended to an OSU is obtained without adding a dynamic function, such as an optical switch, to a W-MULDEM. The W-MULDEM of an optical wavelength division multiplexing access system divides, among ports corresponding to the individual ONUs, downstream optical signals having wavelengths ?d1 to ?dn, which are received along a current-use optical fiber, or downstream optical signals having wavelengths ?d1+?? to ?dn+??, which are received along a redundant optical fiber. The W-MULDEM also multiplexes, for the port that corresponds to the current-use optical fiber or the redundant optical fiber, upstream optical signals having wavelengths ?u1 to ?un or wavelengths ?u1+?? to ?un+??, which are received along optical fibers corresponding to the ONUs. A wavelength difference between the downstream optical signal and the upstream optical signal that are consonant with each ONU is defined as an integer times the FSR of an AWG.Type: ApplicationFiled: May 28, 2004Publication date: March 23, 2006Inventors: Hirotaka Nakamura, Junichi Kani, Hiroo Suzuki, Mitsuhiro Teshima, Ukyo Yamaguchi, Hidetaka Onishi, Katsumi Iwatsuki
-
Publication number: 20060024066Abstract: An optical modulation apparatus is provided which implements a stable amplifying function by reducing the effect of reflected light rays form end faces of a bidirectional optical amplifier by imposing a numerical limitation on the relationship between the gain of the bidirectional optical amplifier and the loss of the optical modulator, or by inserting a polarization rotation section in a reflection type optical modulator including the bidirectional optical amplifier or in a multi-wavelength collective optical modulation system combining the multiple optical modulators. An optical modulation apparatus is provided which implements a stable amplifying function and cost reduction by reducing the effect of reflected light rays by interposing optical isolators at every alternate SOAs in a transmission-type optical modulation apparatus including a plurality of semiconductor optical amplifiers (SOAs) connected in a multistage fashion.Type: ApplicationFiled: June 16, 2004Publication date: February 2, 2006Inventors: Masamichi Fujiwara, Junichi Kani, Koji Akimoto, Katsumi Iwatsuki
-
Patent number: 6924924Abstract: A multi-wavelength generating apparatus generates a wavelength division multiplexing (WDM) signal by modulating light with a single central frequency and with an electric signal having a particular pulse repetition frequency. The resulting optical spectrum configuration is controllable so that a Relative Intensity Noise (RIN) or Signal to Noise Ratio (SNR) requirement may be achieved. A modulated or pulsed light source is used to obtain a discrete spectrum with particular mode spacing, which is then modulated to permit dynamic power control for specific modes of the discrete spectrum.Type: GrantFiled: September 4, 2003Date of Patent: August 2, 2005Assignee: Nippon Telegraph and Telephone CorporationInventors: Masamichi Fujiwara, Katsuhiro Araya, Mitsuhiro Teshima, Junichi Kani, Kenichi Suzuki
-
Publication number: 20050008373Abstract: With respect to the relative intensity noise (RIN) for inputs to an optical modulator or the signal-to-noise ratio (SNR) for outputs therefrom, the optical modulator modulating coherent lights of different wavelengths obtained by slicing a spectrum of the multi-wavelength light, the shape of a spectrum of a multi-wavelength light is controlled so that predetermined RIN and SNR can be obtained in accordance with transmission system parameters (the type and distance of optical fibers, the number of repeaters), thus enabling design meeting a performance specification for a conventional transmission section using semiconductor lasers.Type: ApplicationFiled: April 16, 2004Publication date: January 13, 2005Inventors: Masamichi Fujiwara, Katsuhiro Araya, Mitsuhiro Teshima, Junichi Kani, Kenichi Suzuki
-
Patent number: 6831774Abstract: Amulti-wavelength generating apparatus generates a wavelength division multiplexing (WDM) signal by modulating light with a single central frequency and an electric signal having a particular pulse repetition frequency. The resulting optical spectrum configuration is conntrollable so that a Relative Intensity Noise (RIN) or Signal to Noise Ratio (SNR) requirement may be achieved. A modulated or pulsed light source in used to obtain a descrete spectrum with particular mode spacing, which is then modulated to permit dynamic power control for specific modes of the discrete spectrum.Type: GrantFiled: July 6, 2001Date of Patent: December 14, 2004Assignee: Nippon Telegraph and Telephone CorporationInventors: Masamichi Fujiwara, Katsuhiro Araya, Mitsuhiro Teshima, Junichi Kani, Kenichi Suzuki
-
Publication number: 20040100682Abstract: With respect to the relative intensity noise (RIN) for inputs to an optical modulator or the signal-to-noise ratio (SNR) for outputs therefrom, the optical modulator modulating coherent lights of different wavelengths obtained by slicing a spectrum of the multi-wavelength light, the shape of a spectrum of a multi-wavelength light is controlled so that predetermined RIN and SNR can be obtained in accordance with transmission system parameters (the type and distance of optical fibers, the number of repeaters), thus enabling design meeting a performance specification for a conventional transmission section using semiconductor lasers.Type: ApplicationFiled: September 4, 2003Publication date: May 27, 2004Applicants: Nippon Telegraph and Telephone Corp., International Rectifier CorporationInventors: Masamichi Fujiwara, Katsuhiro Araya, Mitsuhiro Teshima, Junichi Kani, Kenichi Suzuki
-
Patent number: 6583924Abstract: In the optical amplifier an optical divider based on long wavelength (or short wavelength) transmission type dielectric multi-layer filter divides input signal light according to wavelengths, and amplifying sections disposed in parallel and having different respective wavelength amplification regions respectively amplify light signals emitted from the optical divider, and an optical combiner based on long wavelength (or short wavelength) transmission type dielectric multi-layer filter combines light signals output from the respective amplifying sections. In another configuration of the optical amplifier, input signal light is divided using an optical divider based on a dielectric multi-layer filter of a long wavelength (or short wavelength) transmission type, and output signals from the divider are filtered using an optical filter connected in series to a short wavelength (or long wavelength) amplifier generating a loss in the long wavelength (or short wavelength) region of the light signals.Type: GrantFiled: June 27, 2002Date of Patent: June 24, 2003Assignee: Nippon Telegraph and Telephone CorporationInventors: Hiroji Masuda, Junichi Kani, Noboru Takachio
-
Publication number: 20020196530Abstract: In the optical amplifier an optical divider based on long wavelength (or short wavelength) transmission type dielectric multi-layer filter divides input signal light according to wavelengths, and amplifying sections disposed in parallel and having different respective wavelength amplification regions respectively amplify light signals emitted from the optical divider, and an optical combiner based on long wavelength (or short wavelength) transmission type dielectric multi-layer filter combines light signals output from the respective amplifying sections. In another configuration of the optical amplifier, input signal light is divided using an optical divider based on a dielectric multi-layer filter of a long wavelength (or short wavelength) transmission type, and output signals from the divider are filtered using an optical filter connected in series to a short wavelength (or long wavelength) amplifier generating a loss in the long wavelength (or short wavelength) region of the light signals.Type: ApplicationFiled: June 27, 2002Publication date: December 26, 2002Inventors: Hiroji Masuda, Junichi Kani, Noboru Takachio
-
Patent number: 6469826Abstract: In the optical amplifier an optical divider based on long wavelength (or short wavelength) transmission type dielectric multi-layer filter divides input signal light according to wavelengths, and amplifying sections disposed in parallel and having different respective wavelength amplification regions respectively amplify light signals emitted from the optical divider, and an optical combiner based on long wavelength (or short wavelength) transmission type dielectric multi-layer filter combines light signals output from the respective amplifying sections. In another configuration of the optical amplifier, input signal light is divided using an optical divider based on a dielectric multi-layer filter of a long wavelength (or short wavelength) transmission type, and output signals from the divider are filtered using an optical filter connected in series to a short wavelength (or long wavelength) amplifier generating a loss in the long wavelength (or short wavelength) region of the light signals.Type: GrantFiled: July 10, 2000Date of Patent: October 22, 2002Assignee: Nippon Telegraph and Telephone CorporationInventors: Hiroji Masuda, Junichi Kani, Noboru Takachio
-
Publication number: 20020015212Abstract: With respect to the relative intensity noise (RIN) for inputs to an optical modulator or the signal-to-noise ratio (SNR) for outputs therefrom, the optical modulator modulating coherent lights of different wavelengths obtained by slicing a spectrum of the multi-wavelength light, the shape of a spectrum of a multi-wavelength light is controlled so that predetermined RIN and SNR can be obtained in accordance with transmission system parameters (the type and distance of optical fibers, the number of repeaters), thus enabling design meeting a performance specification for a conventional transmission section using semiconductor lasers.Type: ApplicationFiled: July 6, 2001Publication date: February 7, 2002Inventors: Masamichi Fujiwara, Katsuhiro Araya, Mitsuhiro Teshima, Junichi Kani, Kenichi Suzuki