Patents by Inventor Toshihiko Hirooka
Toshihiko Hirooka 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: 11912612Abstract: The present invention provides a plating film that exhibits good adhesion to glass substrates. The present invention is a plating film comprising an oxide layer, an electroless plating film, and an electrolytic copper plating film in this order.Type: GrantFiled: June 1, 2022Date of Patent: February 27, 2024Assignees: OKUNO CHEMICAL INDUSTRIES CO., LTD., PANASONIC HOLDINGS CORPORATIONInventors: Mayu Tsukuda, Toshimitsu Nagao, Junichi Katayama, Kazuya Shimada, Masahito Hayamizu, Toshihiko Sakata, Shuhei Fuku, Asuka Hirooka
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Patent number: 8170071Abstract: Provided is a laser apparatus including: a DFB fiber laser 40 including, as an amplitude medium, a rare earth doped silica optical fiber codoped with a high concentration of aluminum; an optical feedback path 50 formed by a ring-shaped optical fiber; and an optical coupler 70 a) feeding back a part of an output of the DFB fiber laser 40 to the DFB fiber laser 40 via the optical feedback path 50, and b) outputting, to outside, another part of the output of the DFB fiber laser 40, where the optical fiber forming the optical feedback path 50 is longer than a length at which a relaxation oscillation noise in the output to the outside becomes ?110 dB/Hz.Type: GrantFiled: March 5, 2009Date of Patent: May 1, 2012Assignees: Advantest CorporationInventors: Masataka Nakazawa, Akihito Suzuki, Toshihiko Hirooka, Masato Yoshida, Kazunori Shiota
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Patent number: 7747175Abstract: To compensate a waveform distortion by using a nature that a spectral shape is perfectly retained even if all the linear distortions occur on a time-axis. An optical pulse transmitted from an optical pulse transmitter (1) via an optical fiber transmission line (2) is transmitted. An optical Fourier transformer (3) receives an optical pulse, and optically Fourier-transforms an optical pulse on a time-axis onto a frequency-axis to reproduce the frequency spectrum of an optical pulse on a time-axis be effecting switching between frequency and time, thereby compensating a waveform distortion by a linear effect on the optical fiber transmission line (2). A photodetector (4) receives an optical pulse from the optical Fourier transformer (3) and transforms this into an electrical signal to thereby obtain a pulse waveform before a transmission over the optical fiber transmission line (2).Type: GrantFiled: January 23, 2004Date of Patent: June 29, 2010Assignee: Japan Science and Technology AgencyInventors: Toshihiko Hirooka, Masataka Nakazawa
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Publication number: 20100061408Abstract: Provided is a laser apparatus including: a DFB fiber laser 40 including, as an amplitude medium, a rare earth doped silica optical fiber codoped with a high concentration of aluminum; an optical feedback path 50 formed by a ring-shaped optical fiber; and an optical coupler 70 a) feeding back a part of an output of the DFB fiber laser 40 to the DFB fiber laser 40 via the optical feedback path 50, and b) outputting, to outside, another part of the output of the DFB fiber laser 40, where the optical fiber forming the optical feedback path 50 is longer than a length at which a relaxation oscillation noise in the output to the outside becomes ?110 dB/Hz.Type: ApplicationFiled: March 5, 2009Publication date: March 11, 2010Applicant: ADVANTEST CORPORATIONInventors: MASATAKA NAKAZAWA, AKIHITO SUZUKI, TOSHIHIKO HIROOKA, MASATO YOSHIDA, KAZUNORI SHIOTA
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Patent number: 7672593Abstract: An OTDM transmitting method and transmitter realizing an OTDM distortion-free transmission substantially not relying upon dispersion. A time division multiplexed OTDM signal from an OTDM signal transmitter (1) enters an optical Fourier transform unit (2). Optical Fourier transform can be carried out most accurately so long as the optical pulse is a chirp-free Fourier transform limit pulse. The optical Fourier transform unit (2) converts the time waveform of the pulse into a signal on the frequency axis, and an optical inverse Fourier transform unit (2?) converts a spectral shape on the frequency axis into a time waveform (pulse). An optical fiber transmission line (3) is a transmission line having an arbitrary dispersion and a polarization mode dispersion. These dispersions may involve a time variation. An OTDM signal receiver (4) demultiplexes a transmission signal into low-speed optical signals, in a light region, receives optical pulses for respective channels and converts them into electric signals.Type: GrantFiled: March 23, 2004Date of Patent: March 2, 2010Assignee: Japan Science and Technology AgencyInventors: Toshihiko Hirooka, Masataka Nakazawa
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Patent number: 7428096Abstract: A small-sized, high-functionality optical pulse compressor capable of generating a low-power, high-repetition-frequency ultrashort pulse train used for ultrafast optical communication and photometry, and a simple-structure optical function generator for realizing an arbitrary time waveform. The optical pulse compressor comprises and optical Fourier transform device (F) having an optical phase modulator (9) driven by the repetition-frequency of an input optical pulse train and a dispersive medium (8), for converting the shape of an input optical pulse frequency spectrum into its time waveform, and an optical filter (3) inserted ahead of the optical Fourier transform device (F), for reducing the spectrum width of an input optical pulse, wherein the optical Fourier transform device (F) converts a small-spectrum-width optical pulse output from the optical function generator generates an optical pulse.Type: GrantFiled: March 23, 2004Date of Patent: September 23, 2008Assignee: Japan Science and Technology AgencyInventors: Masataka Nakazawa, Toshihiko Hirooka
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Patent number: 7352504Abstract: Optical Fourier transform is executed over a wide time range. A quadratic function type optical pulse generator (7) generates a control light pulse of a shape expressed by a quadratic function or a parabola according to a clock signal based on a signal light pulse from an optical coupler (1). The signal light pulse inputted is multiplexed by a multiplexer (9) with the control light pulse optically delayed by an optical delay element (8) so that the timing is matched with the signal light pulse, and introduced into an optical Kerr medium (10). In the optical Kerr medium (10), the signal light pulse inputted by the mutual phase modulation between the signal light pulse and the control light pulse is subjected to a linear phase modulation (frequency chirp) over the entire pulse or a wide time range.Type: GrantFiled: December 27, 2004Date of Patent: April 1, 2008Assignee: Japan Science and Technology AgencyInventors: Toshihiko Hirooka, Masataka Nakazawa
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Publication number: 20070273958Abstract: Optical Fourier transform is executed over a wide time range. A quadratic function type optical pulse generator (7) generates a control light pulse of a shape expressed by a quadratic function or a parabola according to a clock signal based on a signal light pulse from an optical coupler (1). The signal light pulse inputted is multiplexed by a multiplexer (9) with the control light pulse optically delayed by an optical delay element (8) so that the timing is matched with the signal light pulse, and introduced into an optical Kerr medium (10). In the optical Kerr medium (10), the signal light pulse inputted by the mutual phase modulation between the signal light pulse and the control light pulse is subjected to a linear phase modulation (frequency chirp) over the entire pulse or a wide time range.Type: ApplicationFiled: December 27, 2004Publication date: November 29, 2007Inventors: Toshihiko Hirooka, Masataka Nakazawa
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Publication number: 20070109957Abstract: An OTDM transmitting method and transmitter realizing an OTDM distortion-free transmission substantially not relying upon dispersion. A time division multiplexed OTDM signal from an OTDM signal transmitter (1) enters an optical Fourier transform unit (2). Optical Fourier transform can be carried out most accurately so long as the optical pulse is a chirp-free Fourier transform limit pulse. The optical Fourier transform unit (2) converts the time waveform of the pulse into a signal on the frequency axis, and an optical inverse Fourier transform unit (2?) converts a spectral shape on the frequency axis into a time waveform (pulse). An optical fiber transmission line (3) is a transmission line having an arbitrary dispersion and a polarization mode dispersion. These dispersions may involve a time variation. An OTDM signal receiver (4) demultiplexes a transmission signal into low-speed optical signals, in a light region, receives optical pulses for respective channels and converts them into electric signals.Type: ApplicationFiled: March 23, 2004Publication date: May 17, 2007Applicant: Japan Science and Technology AgencyInventors: Toshihiko Hirooka, Masataka Nakazawa
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Publication number: 20070025728Abstract: A small-sized, high-functionality optical pulse compressor capable of generating a low-power, high-repetition-frequency ultrashort pulse train used for ultralast optical communication and photometry, and a simple-structure optical function generator for realizing an arbitrary time waveform. The optical pulse compressor comprises and optical Fourier transform device (F) having an optical phase modulator (9) driven by the repetition-frequency of an input optical pulse train and a dispersive medium (8), for converting the shape of an input optical pulse frequency spectrum into its time waveform, and an optical filter (3) inserted ahead of the optical Fourier transform device (F), for reducing the spectrum width of an input optical pulse, wherein the optical Fourier transform device (F) converts a small-spectrum-width optical pulse output from the optical function generator generates an optical pulse.Type: ApplicationFiled: March 23, 2004Publication date: February 1, 2007Applicant: Japan Science and Technology AgencyInventors: Masataka Nakazawa, Toshihiko Hirooka
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Publication number: 20060232847Abstract: To compensate a waveform distortion by using a nature that a spectral shape is perfectly retained even if all the linear distortions occur on a time-axis. An optical pulse transmitted from an optical pulse transmitter (1) via an optical fiber transmission line (2) is transmitted. An optical Fourier transformer (3) receives an optical pulse, and optically Fourier-transforms an optical pulse on a time-axis onto a frequency-axis to reproduce the frequency spectrum of an optical pulse on a time-axis be effecting switching between frequency and time, thereby compensating a waveform distortion by a linear effect on the optical fiber transmission line (2). A photodetector (4) receives an optical pulse from the optical Fourier transformer (3) and transforms this into an electrical signal to thereby obtain a pulse waveform before a transmission over the optical fiber transmission line (2).Type: ApplicationFiled: January 23, 2004Publication date: October 19, 2006Applicant: JAPAN SCIENCE AND TECHNOLOGY AGENCYInventors: Toshihiko Hirooka, Masataka Nakazawa