Patents by Inventor Akira Tokuhisa

Akira Tokuhisa 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: 11366070
    Abstract: A pulsed light generation device includes: an optical coupler having four input/output ports including a first port, a second port, a third port and a fourth port; a connection optical path that connects the third port with the fourth port; and a phase modulation element disposed in the connection optical path. The optical coupler branches pulsed light input to the first port and outputs the branched input pulsed light as first-direction pulsed light and second-direction pulsed light to the third port and to the fourth port. The modulation element applies phase modulation to either one of the first-direction pulsed light and the second-direction pulsed light, thereby outputs output pulsed lights through the first port and the second port, wherein a waveform of one of the pulsed lights output through the first port is different from a waveform of the other of the output pulsed lights output through the second port.
    Type: Grant
    Filed: November 26, 2018
    Date of Patent: June 21, 2022
    Assignee: NIKON CORPORATION
    Inventor: Akira Tokuhisa
  • Publication number: 20220190547
    Abstract: A pulsed light generation device, includes: a first optical fiber through which first pulsed light and second pulsed light, having an intensity that decreases while an intensity of the first pulsed light increases, and increases while the intensity of the first pulsed light decreases, having been multiplexed and entered therein, are propagated; and a second optical fiber at which the first pulsed light, having exited the first optical fiber and entered therein, is amplified while being propagated therein, wherein: at the first optical fiber, phase modulation occurs in the first pulsed light due to cross phase modulation caused by the second pulsed light; and self-phase modulation occurring in the first pulsed light at the second optical fiber is diminished by the phase modulation having occurred at the first optical fiber.
    Type: Application
    Filed: December 20, 2021
    Publication date: June 16, 2022
    Applicant: NIKON CORPORATION
    Inventor: Akira TOKUHISA
  • Publication number: 20220146420
    Abstract: A terahertz light detector includes: a light reception unit that receives terahertz light from a measured object; a pulse laser that generates pulse light; an optical member which the pulse light enters; and a control unit that controls the energy of the pulse light which enters the optical member, wherein the optical member has anomalous dispersion, and the light reception unit outputs a signal that is dependent on an intensity of terahertz light when the pulse light emitted from the optical member enters the light reception unit.
    Type: Application
    Filed: March 18, 2020
    Publication date: May 12, 2022
    Applicant: NIKON CORPORATION
    Inventor: Akira TOKUHISA
  • Patent number: 11303091
    Abstract: A pulsed light generation device, includes: a first optical fiber through which first pulsed light and second pulsed light, having an intensity that decreases while an intensity of the first pulsed light increases, and increases while the intensity of the first pulsed light decreases, having been multiplexed and entered therein, are propagated; and a second optical fiber at which the first pulsed light, having exited the first optical fiber and entered therein, is amplified while being propagated therein, wherein: at the first optical fiber, phase modulation occurs in the first pulsed light due to cross phase modulation caused by the second pulsed light; and self-phase modulation occurring in the first pulsed light at the second optical fiber is diminished by the phase modulation having occurred at the first optical fiber.
    Type: Grant
    Filed: January 3, 2020
    Date of Patent: April 12, 2022
    Assignee: NIKON CORPORATION
    Inventor: Akira Tokuhisa
  • Publication number: 20200153193
    Abstract: A pulsed light generation device, includes: a first optical fiber through which first pulsed light and second pulsed light, having an intensity that decreases while an intensity of the first pulsed light increases, and increases while the intensity of the first pulsed light decreases, having been multiplexed and entered therein, are propagated; and a second optical fiber at which the first pulsed light, having exited the first optical fiber and entered therein, is amplified while being propagated therein, wherein: at the first optical fiber, phase modulation occurs in the first pulsed light due to cross phase modulation caused by the second pulsed light; and self-phase modulation occurring in the first pulsed light at the second optical fiber is diminished by the phase modulation having occurred at the first optical fiber.
    Type: Application
    Filed: January 3, 2020
    Publication date: May 14, 2020
    Applicant: NIKON CORPORATION
    Inventor: Akira TOKUHISA
  • Patent number: 10559937
    Abstract: A pulsed light generation device, includes: a first optical fiber through which first pulsed light and second pulsed light, having an intensity that decreases while an intensity of the first pulsed light increases, and increases while the intensity of the first pulsed light decreases, having been multiplexed and entered therein, are propagated; and a second optical fiber at which the first pulsed light, having exited the first optical fiber and entered therein, is amplified while being propagated therein, wherein: at the first optical fiber, phase modulation occurs in the first pulsed light due to cross phase modulation caused by the second pulsed light; and self-phase modulation occurring in the first pulsed light at the second optical fiber is diminished by the phase modulation having occurred at the first optical fiber.
    Type: Grant
    Filed: November 26, 2018
    Date of Patent: February 11, 2020
    Assignee: NIKON CORPORATION
    Inventor: Akira Tokuhisa
  • Publication number: 20190131756
    Abstract: A pulsed light generation device, includes: a first optical fiber through which first pulsed light and second pulsed light, having an intensity that decreases while an intensity of the first pulsed light increases, and increases while the intensity of the first pulsed light decreases, having been multiplexed and entered therein, are propagated; and a second optical fiber at which the first pulsed light, having exited the first optical fiber and entered therein, is amplified while being propagated therein, wherein: at the first optical fiber, phase modulation occurs in the first pulsed light due to cross phase modulation caused by the second pulsed light; and self-phase modulation occurring in the first pulsed light at the second optical fiber is diminished by the phase modulation having occurred at the first optical fiber.
    Type: Application
    Filed: November 26, 2018
    Publication date: May 2, 2019
    Applicant: NIKON CORPORATION
    Inventor: Akira TOKUHISA
  • Publication number: 20190094686
    Abstract: A pulsed light generation device includes: an optical coupler having four input/output ports including a first port, a second port, a third port and a fourth port; a connection optical path that connects the third port with the fourth port; and a phase modulation element disposed in the connection optical path. The optical coupler branches pulsed light input to the first port and outputs the branched input pulsed light as first-direction pulsed light and second-direction pulsed light to the third port and to the fourth port. The modulation element applies phase modulation to either one of the first-direction pulsed light and the second-direction pulsed light, thereby outputs output pulsed lights through the first port and the second port, wherein a waveform of one of the pulsed lights output through the first port is different from a waveform of the other of the output pulsed lights output through the second port.
    Type: Application
    Filed: November 26, 2018
    Publication date: March 28, 2019
    Applicant: NIKON CORPORATION
    Inventor: Akira TOKUHISA
  • Patent number: 10044160
    Abstract: A pulsed light generating method for generating a pulsed light by cutting out a laser light outputted from a laser light source with an intensity modulation type electro optic modulator, wherein: the electro optic modulator is driven by use of a drive signal that changes a voltage applied to the electro optic modulator between a voltage lower than a reference voltage and a voltage higher than the reference voltage, the reference voltage being a voltage applied to the electro optic modulator at which a transmittance of the laser light transmitting through the electro optic modulator is local maximum.
    Type: Grant
    Filed: August 16, 2016
    Date of Patent: August 7, 2018
    Assignee: NIKON CORPORATION
    Inventors: Naoto Inaba, Akira Tokuhisa
  • Patent number: 9882340
    Abstract: A laser device includes: a laser light source which generates a laser light in a pulse waveform of preset predetermined frequency; intensity modulator which is driven with a transmittance waveform wherein transmittance changes at either the predetermined frequency or an integer-multiple frequency thereof and which extracts and outputs the laser light which is outputted from the laser light source; control unit which controls an operation of the intensity modulator; an amplifier which amplifies the laser light which is outputted from the intensity modulator; and a wavelength conversion optical element which converts a wavelength of the laser light which is amplified by the amplifier, wherein the control unit changes relative timing of the transmittance waveform with respect to the pulse waveform, thereby changing the pulse waveform of the laser light which is emitted from the intensity modulator, to output a pulse light of predetermined waveform from the wavelength conversion optical element.
    Type: Grant
    Filed: April 25, 2016
    Date of Patent: January 30, 2018
    Assignee: NIKON CORPORATION
    Inventor: Akira Tokuhisa
  • Patent number: 9608400
    Abstract: A laser device, includes: a laser light generating unit generates laser lights with first and second wavelengths; an amplifying unit amplifies the lights with first and second wavelengths the first and the second amplified lights; a wavelength converting unit that generates a light output, either of first converted light wavelength conversion of the first amplified light and the second amplified light, or of the first converted light and the second converted light wavelength conversion of the second amplified light; and a control unit that controls operation of the laser light generating unit, wherein: the control unit controls an output condition of the light output by adjusting a temporal overlap, of the first converted light and the second amplified light, or the first and second converted lights, through control of relative timings of the laser light with the first and second wavelengths.
    Type: Grant
    Filed: July 31, 2013
    Date of Patent: March 28, 2017
    Assignee: NIKON CORPORATION
    Inventor: Akira Tokuhisa
  • Publication number: 20160359290
    Abstract: A pulsed light generating method for generating a pulsed light by cutting out a laser light outputted from a laser light source with an intensity modulation type electro optic modulator, wherein: the electro optic modulator is driven by use of a drive signal that changes a voltage applied to the electro optic modulator between a voltage lower than a reference voltage and a voltage higher than the reference voltage, the reference voltage being a voltage applied to the electro optic modulator at which a transmittance of the laser light transmitting through the electro optic modulator is local maximum.
    Type: Application
    Filed: August 16, 2016
    Publication date: December 8, 2016
    Applicant: NIKON CORPORATION
    Inventors: Naoto INABA, Akira TOKUHISA
  • Publication number: 20160240993
    Abstract: A laser device includes: a laser light source which generates a laser light in a pulse waveform of preset predetermined frequency; intensity modulator which is driven with a transmittance waveform wherein transmittance changes at either the predetermined frequency or an integer-multiple frequency thereof and which extracts and outputs the laser light which is outputted from the laser light source; control unit which controls an operation of the intensity modulator; an amplifier which amplifies the laser light which is outputted from the intensity modulator; and a wavelength conversion optical element which converts a wavelength of the laser light which is amplified by the amplifier, wherein the control unit changes relative timing of the transmittance waveform with respect to the pulse waveform, thereby changing the pulse waveform of the laser light which is emitted from the intensity modulator, to output a pulse light of predetermined waveform from the wavelength conversion optical element.
    Type: Application
    Filed: April 25, 2016
    Publication date: August 18, 2016
    Applicant: NIKON CORPORATION
    Inventor: Akira TOKUHISA
  • Patent number: 9383653
    Abstract: An ultraviolet laser device, includes: a first laser light output unit outputs a first infrared laser light; a second laser light output unit outputs a second infrared laser light; a first wavelength conversion optical system generates a first ultraviolet laser light of a fifth harmonic of the first infrared laser light; and a second wavelength conversion optical system to which the first ultraviolet laser light and the second infrared laser light enter, wherein the second wavelength conversion optical system includes a first wavelength conversion optical element which generates a second ultraviolet laser light by sum frequency generation of the first ultraviolet laser light and the second infrared laser light, and a second wavelength conversion optical element which generates a deep ultraviolet laser light by sum frequency generation of the second ultraviolet laser light and the second infrared laser light.
    Type: Grant
    Filed: March 5, 2013
    Date of Patent: July 5, 2016
    Assignee: NIKON CORPORATION
    Inventor: Akira Tokuhisa
  • Patent number: 9172204
    Abstract: A laser device includes: a signal light source that outputs seed light; an electro-optic modulator that chops a portion of the seed light outputted from the signal light source and outputs signal light; an optical amplifier that amplifies the signal light outputted from the electro-optic modulator; a wavelength conversion optical element that wavelength converts the signal light amplified by the optical amplifier; a converted light detector that detects the signal light that has been wavelength converted by the wavelength conversion optical element; and an EU control unit that controls the operation of the electro-optic modulator, wherein the EU control unit is adapted, in the state in which the seed light is being outputted, to adjust bias voltage of the electro-optic modulator on the basis of the applied voltage when the intensity of the signal light after wavelength conversion detected by the converted light detector becomes substantially maximum.
    Type: Grant
    Filed: February 10, 2012
    Date of Patent: October 27, 2015
    Assignee: NIKON CORPORATION
    Inventors: Akira Tokuhisa, Yasutoshi Takada
  • Publication number: 20150303647
    Abstract: A laser device, includes: a laser light generating unit generates laser lights with first and second wavelengths; an amplifying unit amplifies the lights with first and second wavelengths the first and the second amplified lights; a wavelength converting unit that generates a light output, either of first converted light wavelength conversion of the first amplified light and the second amplified light, or of the first converted light and the second converted light wavelength conversion of the second amplified light; and a control unit that controls operation of the laser light generating unit, wherein: the control unit controls an output condition of the light output by adjusting a temporal overlap, of the first converted light and the second amplified light, or the first and second converted lights, through control of relative timings of the laser light with the first and second wavelengths.
    Type: Application
    Filed: July 31, 2013
    Publication date: October 22, 2015
    Inventor: Akira TOKUHISA
  • Patent number: 9160132
    Abstract: The present invention greatly reduces the likelihood that fiber fusion will occur. A laser apparatus comprises an excitation light source and an optical amplifier unit, which optically amplifies by receiving excitation light that is output from the excitation light source and that transits an optical fiber. A monitor unit monitors the power level of the excitation light transmitted from the excitation light source to the optical amplifier unit side via the optical fiber.
    Type: Grant
    Filed: February 17, 2011
    Date of Patent: October 13, 2015
    Assignee: NIKON CORPORATION
    Inventors: Yasutoshi Takada, Akira Tokuhisa
  • Patent number: 9153934
    Abstract: A fundamental wavelength light generating unit generates light of a fundamental wavelength in accordance with an output wavelength instruction signal. An optical amplifier unit amplifies the light of the fundamental wavelength. A wavelength converting part includes nonlinear optical crystals that each perform wavelength conversion and temperature regulators that each regulate the temperature of the corresponding nonlinear optical crystal, wherein the wavelength converting part converts the light amplified by the optical amplifier unit to light of the wavelength indicated by the output wavelength instruction signal. A storage unit stores correspondence information that indicates a correspondence relationship between the wavelength of the output light and the temperature of each of the nonlinear optical crystals based on the corresponding wavelength.
    Type: Grant
    Filed: March 30, 2011
    Date of Patent: October 6, 2015
    Assignee: NIKON CORPORATION
    Inventors: Yasutoshi Takada, Akira Tokuhisa
  • Patent number: 9083151
    Abstract: When the laser light source is caused to standby, the temperatures of semiconductor lasers are changed by approximately 3° C. from the temperature when the laser light source is always being used. With a temperature change of approximately 3° C., the wavelengths of the laser light generated by the semiconductor lasers change approximately 0.3 nm. This change hardly has any effect at all on optical fiber amplifiers, but the conversion efficiencies at the respective wavelength conversion elements of the wavelength conversion optical system change, and, particularly, deep ultraviolet light is hardly generated at all any longer. Therefore, even while the laser light has been made incident to the wavelength conversion optical system, there is no longer damaging of the wavelength conversion elements. Therefore, it is possible to provide a laser light source standby method that is able to shorten the start up time of the laser light source.
    Type: Grant
    Filed: June 7, 2011
    Date of Patent: July 14, 2015
    Assignee: NIKON CORPORATION
    Inventors: Akira Tokuhisa, Yasutoshi Takada
  • Publication number: 20150116680
    Abstract: An ultraviolet laser device, includes: a first laser light output unit outputs a first infrared laser light; a second laser light output unit outputs a second infrared laser light; a first wavelength conversion optical system generates a first ultraviolet laser light of a fifth harmonic of the first infrared laser light; and a second wavelength conversion optical system to which the first ultraviolet laser light and the second infrared laser light enter, wherein the second wavelength conversion optical system includes a first wavelength conversion optical element which generates a second ultraviolet laser light by sum frequency generation of the first ultraviolet laser light and the second infrared laser light, and a second wavelength conversion optical element which generates a deep ultraviolet laser light by sum frequency generation of the second ultraviolet laser light and the second infrared laser light.
    Type: Application
    Filed: March 5, 2013
    Publication date: April 30, 2015
    Inventor: Akira Tokuhisa