Patents by Inventor Yu Mimura

Yu Mimura 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: 20080124036
    Abstract: The present invention can easily realize an optical fiber and an optical transmission line that can propagate a light in a single mode while lowering a macro-bending loss against a small-diameter bending. An optical fiber 1 according to the present invention includes a first cladding region 3 having a refractive index lower than a refractive index of a core region 2 on outer circumference of the core region 2. Sub-medium regions 5a to 5f, 6a to 6f are arranged in multilayer in the first cladding region 3, which have a refractive index lower than a refractive index of a main-medium region of the first cladding region 3. The sub-medium regions 5a to 5f having a circular shape with a lateral cross section of a diameter d1 is arranged in an inner cladding area 3a of the first cladding region 3, and the sub-medium regions 6a to 6f having a circular shape with a lateral cross section of a diameter d2 (>d1) is arranged in an outer cladding area 3b of the first cladding region 3.
    Type: Application
    Filed: September 13, 2006
    Publication date: May 29, 2008
    Applicant: THE FURUKAWA ELECTRIC CO., LTD.
    Inventors: Ryo Miyabe, Yu Mimura
  • Patent number: 7369232
    Abstract: An object is to accurately measure the Stokes parameters, without the occurrence of polarization fluctuations or PDL during the splitting of the incident light. When the incident light is made incident on a first-stage prism, the light is split into two first splitting light rays. Next, the first split light rays are respectively incident on a pair of prisms of a second stage. Each of the pair of first split light rays is split into two rays by a second-stage prism, to obtain four second split light rays.
    Type: Grant
    Filed: May 31, 2005
    Date of Patent: May 6, 2008
    Assignee: The Furukawa Electric Co., Ltd.
    Inventors: Mieko Yamagaki, Yu Mimura, Kazuyou Mizuno, Takeshi Takagi
  • Patent number: 7190850
    Abstract: A PMD emulator configured by connecting in this order: an input-side optical fiber 71 for receiving light to be measured; a first polarization rotating portion 73 including M DGD sections 76 (M is an integer equal to or more than 2) concatenated by (M?1) polarization rotators 80, one DGD section being arranged at each end of said first polarization rotating portion; an arbitrary-arbitrary polarization controller 75 for changing any state of polarization into any other state of polarization, a second PMD rotating portion 74 configured in the same way as the first polarization rotating portion 73 an output-side optical fiber for outputting the light to be measured.
    Type: Grant
    Filed: March 24, 2005
    Date of Patent: March 13, 2007
    Assignee: The Furukawa Electric Co., Ltd.
    Inventors: Yu Mimura, Kazuhiro Ikeda
  • Publication number: 20070035722
    Abstract: A method of simultaneously specifying the wavelength dispersion and nonlinear coefficient of an optical fiber. Pulsed probe light and pulsed pump light are first caused to enter an optical fiber to be measured. Then, the power oscillation of the back-scattered light of the probe light or idler light generated within the optical fiber is measured. Next, the instantaneous frequency of the measured power oscillation is obtained, and the dependency of the instantaneous frequency relative to the power oscillation of the pump light in a longitudinal direction of the optical fiber is obtained. Thereafter, a rate of change in the longitudinal direction between phase-mismatching conditions and nonlinear coefficient of the optical fiber is obtained from the dependency of the instantaneous frequency. And based on the rate of change, the longitudinal wavelength-dispersion distribution and longitudinal nonlinear-coefficient distribution of the optical fiber are simultaneously specified.
    Type: Application
    Filed: October 13, 2006
    Publication date: February 15, 2007
    Inventors: Masateru Tadakuma, Yu Mimura, Misao Sakano, Osamu Aso, Takeshi Nakajima, Katsutoshi Takahashi
  • Patent number: 7146085
    Abstract: A method of simultaneously specifying the wavelength dispersion and nonlinear coefficient of an optical fiber. Pulsed probe light and pulsed pump light are first caused to enter an optical fiber to be measured. Then, the power oscillation of the back-scattered light of the probe light or idler light generated within the optical fiber is measured. Next, the instantaneous frequency of the measured power oscillation is obtained, and the dependency of the instantaneous frequency relative to the power oscillation of the pump light in a longitudinal direction of the optical fiber is obtained. Thereafter, a rate of change in the longitudinal direction between phase-mismatching conditions and nonlinear coefficient of the optical fiber is obtained from the dependency of the instantaneous frequency. And based on the rate of change, the longitudinal wavelength-dispersion distribution and longitudinal nonlinear-coefficient distribution of the optical fiber are simultaneously specified.
    Type: Grant
    Filed: October 13, 2005
    Date of Patent: December 5, 2006
    Assignee: The Furukawa Electric Co., Ltd.
    Inventors: Masateru Tadakuma, Yu Mimura, Misao Sakano, Osamu Aso, Takeshi Nakajima, Katsutoshi Takahashi
  • Patent number: 7003202
    Abstract: A method of simultaneously specifying the wavelength dispersion and nonlinear coefficient of an optical fiber. Pulsed probe light and pulsed pump light are first caused to enter an optical fiber to be measured. Then, the power oscillation of the back-scattered light of the probe light or idler light generated within the optical fiber is measured. Next, the instantaneous frequency of the measured power oscillation is obtained, and the dependency of the instantaneous frequency relative to the power oscillation of the pump light in a longitudinal direction of the optical fiber is obtained. Thereafter, a rate of change in the longitudinal direction between phase-mismatching conditions and nonlinear coefficient of the optical fiber is obtained from the dependency of the instantaneous frequency. And based on the rate of change, the longitudinal wavelength-dispersion distribution and longitudinal nonlinear-coefficient distribution of thee optical fiber are simultaneously specified.
    Type: Grant
    Filed: April 27, 2004
    Date of Patent: February 21, 2006
    Assignee: The Furukawa Electric Co., Ltd.
    Inventors: Masateru Tadakuma, Yu Mimura, Misao Sakano, Osamu Aso, Takeshi Nakajima, Katsutoshi Takahashi
  • Publication number: 20060029342
    Abstract: A method of simultaneously specifying the wavelength dispersion and nonlinear coefficient of an optical fiber. Pulsed probe light and pulsed pump light are first caused to enter an optical fiber to be measured. Then, the power oscillation of the back-scattered light of the probe light or idler light generated within the optical fiber is measured. Next, the instantaneous frequency of the measured power oscillation is obtained, and the dependency of the instantaneous frequency relative to the power oscillation of the pump light in a longitudinal direction of the optical fiber is obtained. Thereafter, a rate of change in the longitudinal direction between phase-mismatching conditions and nonlinear coefficient of the optical fiber is obtained from the dependency of the instantaneous frequency. And based on the rate of change, the longitudinal wavelength-dispersion distribution and longitudinal nonlinear-coefficient distribution of the optical fiber are simultaneously specified.
    Type: Application
    Filed: October 13, 2005
    Publication date: February 9, 2006
    Inventors: Masateru Tadakuma, Yu Mimura, Misao Sakano, Osamu Aso, Takeshi Nakajima, Katsutoshi Takahashi
  • Publication number: 20050270529
    Abstract: An object is to accurately measure the Stokes parameters, without the occurrence of polarization fluctuations or PDL during the splitting of the incident light. When the incident light is made incident on a first-stage prism, the light is split into two first splitting light rays. Next, the first split light rays are respectively incident on a pair of prisms of a second stage. Each of the pair of first split light rays is split into two rays by a second-stage prism, to obtain four second split light rays.
    Type: Application
    Filed: May 31, 2005
    Publication date: December 8, 2005
    Applicant: The Furukawa Electric Co, Ltd.
    Inventors: Mieko Yamagaki, Yu Mimura, Kazuyou Mizuno, Takeshi Takagi
  • Publication number: 20050244092
    Abstract: A PMD emulator configured by connecting in this order: an input-side optical fiber 71 for receiving light to be measured; a first polarization rotating portion 73 including M DGD sections 76 (M is an integer equal to or more than 2) concatenated by (M?1) polarization rotators 80, one DGD section being arranged at each end of said first polarization rotating portion; an arbitrary-arbitrary polarization controller 75 for changing any state of polarization into any other state of polarization, a second PMD rotating portion 74 configured in the same way as the first polarization rotating portion 73 an output-side optical fiber for outputting the light to be measured.
    Type: Application
    Filed: March 24, 2005
    Publication date: November 3, 2005
    Applicant: The Furukawa Electric Co, Ltd.
    Inventors: Yu Mimura, Kazuhiro Ikeda
  • Patent number: 6933001
    Abstract: The optical thickness of a film formed on a substrate is controlled precisely to manufacture an optical filter having an accurate optical thickness. Time is counted during a film being formed on a substrate to note time points t with respect to a reference time set in advance. At least one of two optical characteristics of energy transmittance and energy reflectance when the film being formed on the substrate is irradiated with monitoring light is expressed by a function f(t) of the time points t based on a theoretical formula of the optical characteristic. The optical characteristic is measured by irradiating the film with the monitoring light at the time points t. A designed thickness achieving time at which the optical thickness of the film designed thickness is predicted. The film formation is stopped at the designed thickness achieving time, thereby obtaining the optical filter.
    Type: Grant
    Filed: January 14, 2002
    Date of Patent: August 23, 2005
    Assignee: The Fukukawa Electric Company, Ltd.
    Inventors: Abe Hiroyuki, Yu Mimura, Kazuyou Mizuno
  • Publication number: 20050058417
    Abstract: A method of simultaneously specifying the wavelength dispersion and nonlinear coefficient of an optical fiber. Pulsed probe light and pulsed pump light are first caused to enter an optical fiber to be measured. Then, the power oscillation of the back-scattered light of the probe light or idler light generated within the optical fiber is measured. Next, the instantaneous frequency of the measured power oscillation is obtained, and the dependency of the instantaneous frequency relative to the power oscillation of the pump light in a longitudinal direction of the optical fiber is obtained. Thereafter, a rate of change in the longitudinal direction between phase-mismatching conditions and nonlinear coefficient of the optical fiber is obtained from the dependency of the instantaneous frequency. And based on the rate of change, the longitudinal wavelength-dispersion distribution and longitudinal nonlinear-coefficient distribution of thee optical fiber are simultaneously specified.
    Type: Application
    Filed: April 27, 2004
    Publication date: March 17, 2005
    Inventors: Masateru Tadakuma, Yu Mimura, Misao Sakano, Osamu Aso, Takeshi Nakajima, Katsutoshi Takahashi
  • Patent number: 6542666
    Abstract: Wavelength multiplex transmission is realized in which the temperature dependency of an EDFA is compensated for in relation to the wavelengths which are used. A first and a second long-period grating which have different periods from each other are formed in an optical fiber, ensuring that the peak wavelength of a waveform representing an optical transmission loss characteristic of the first long-period grating side is located on the shorter wavelength side than a transmission band and a peak wavelength of a waveform representing an optical transmission loss characteristic of the second long-period grating side is located on the longer wavelength side within the transmission band.
    Type: Grant
    Filed: March 12, 2001
    Date of Patent: April 1, 2003
    Assignee: The Furukawa Electric Co., Ltd.
    Inventors: Toshiaki Tsuda, Shigehito Yodo, Kazuyo Mizuno, Yu Mimura, Toshihiko Ohta, Yoshihiro Emori, Shu Namiki
  • Publication number: 20020155213
    Abstract: The optical thickness of a film formed on a substrate is controlled precisely to manufacture an optical filter having an accurate optical thickness. Time is counted during a film (4) is being formed on a substrate (3) so as to note time points t with respect to a reference time that is set in advance. At least one of two optical characteristics consisting of energy transmittance and energy reflectance when the film being formed on the substrate (3) is irradiated with monitoring light is expressed by a function f(t) of the time points t on the basis of the theoretical formula of the optical characteristic. The function f(t) has a theoretical constant ak (k is an integer equal to or greater than 0). The optical characteristic is measured by irradiating the film (4) with the monitoring light at the time points t. A theoretical value of the optical characteristic is calculated from the function f(t).
    Type: Application
    Filed: January 14, 2002
    Publication date: October 24, 2002
    Inventors: Abe Hiroyuki, Yu Mimura, Kazuyou Mizuno
  • Publication number: 20020080833
    Abstract: A semiconductive laser module according to the present invention is configured with a semiconductive laser module having a semiconductive laser device, a cavity formed with at least one light feedback means included, and an optical fiber located at a front side of the cavity, wherein an optical filter for transmitting light of wavelength within a predetermined range is disposed in the cavity. The above-noted semiconductive laser module additionally has a combination of a collimator and a focusing lens for coupling emitted light from the semiconductive laser device with the optical fiber, and the optical filter is disposed between the collimator and the focusing lens. The optical filter has a dielectric multi-layered filter for transmitting a desired wavelength.
    Type: Application
    Filed: November 1, 2001
    Publication date: June 27, 2002
    Applicant: The Furukawa Electric Co., Ltd.
    Inventors: Hiroshi Matsuura, Yu Mimura, Takeshi Aikiyo, Takeo Shimizu
  • Publication number: 20020044736
    Abstract: An optical filter apparatus and a method of designing an optical filter having a target loss wavelength characteristic. The optical filter is formed by combining a plurality of optical parts, each having a periodic loss wavelength characteristic with respect to the wavelength. The loss wavelength characteristic may be determined using a theoretical equation that includes phase and amplitude determining parameters. Nonlinear fitting is used to determine first optimum solutions for respective phase determining parameters from predetermined numerical values. Additionally, groups of numerical values are determined from numerical ranges in the vicinities of the first optimum solutions and nonlinear fitting analysis. Consequently, optimum solutions are successively calculated and respective parameters are determined to reach final optimum solutions. Finally, the determined parameters are used to approximate the loss wavelength characteristic of the optical filter.
    Type: Application
    Filed: April 30, 2001
    Publication date: April 18, 2002
    Inventors: Yu Mimura, Kazuyo Mizuno
  • Publication number: 20020027665
    Abstract: An optical filter having a precise optical thickness is produced by controlling the optical thickness of the film formed on the product substrate precisely. The optical thickness of the film formed on the monitoring chip 2 and the data of the relation of this optical thickness to the reflectance of the film are determined beforehand and used as film thickness control data. On arranging both the product substrate 3 and the monitoring chip 2 within the film forming area 7 to form films on these substrates simultaneously, the correction coefficient for correcting the amount of deviation of the optical thickness of the film formed on the product substrate 3 from the optical thickness of the film formed on the monitoring chip 2 is provided by the film thickness correction coefficient data determined beforehand, for example for each film material and according to the monitor light wavelength.
    Type: Application
    Filed: April 25, 2001
    Publication date: March 7, 2002
    Inventors: Hiroyuki Abe, Yu Mimura, Kazuyo Mizuno
  • Publication number: 20020025115
    Abstract: Wavelength multiplex transmission is realized in which the temperature dependency of an EDFA is compensated for in relation to the wavelengths which are used. A first and a second long-period grating which have different periods from each other are formed in an optical fiber, ensuring that the peak wavelength of a waveform representing an optical transmission loss characteristic of the first long-period grating side is located on the shorter wavelength side than a transmission band and a peak wavelength of a waveform representing an optical transmission loss characteristic of the second long-period grating side is located on the longer wavelength side within the transmission band.
    Type: Application
    Filed: March 12, 2001
    Publication date: February 28, 2002
    Inventors: Toshiaki Tsuda, Shigehito Yodo, Kazuyo Mizuno, Yu Mimura, Toshihiko Ohta, Yoshihiro Emori, Shu Namiki