Patents by Inventor Gyu C. Cho

Gyu C. Cho 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: 7929203
    Abstract: An optimized Yb: doped fiber mode-locked oscillator and fiber amplifier system for seeding Nd: or Yb: doped regenerative amplifiers. The pulses are generated in the Yb: or Nd: doped fiber mode-locked oscillator, and may undergo spectral narrowing or broadening, wavelength converting, temporal pulse compression or stretching, pulse attenuation and/or lowering the repetition rate of the pulse train. The conditioned pulses are subsequently coupled into an Yb: or Nd: fiber amplifier. The amplified pulses are stretched before amplification in the regenerative amplifier that is based on an Nd: or Yb: doped solid-state laser material, and then recompressed for output.
    Type: Grant
    Filed: June 3, 2008
    Date of Patent: April 19, 2011
    Assignee: IMRA America, Inc.
    Inventors: Donald J. Harter, Gyu C. Cho, Martin E. Fermann, Ingmar Hartl
  • Patent number: 7885311
    Abstract: A laser head generating ultrashort pulses is integrated with an active beam steering device in the head. Direct linkage with an application system by means of an adequate interface protocol enables the active device to be controlled directly by the application system.
    Type: Grant
    Filed: March 27, 2007
    Date of Patent: February 8, 2011
    Assignee: IMRA America, Inc.
    Inventors: Gyu C. Cho, Oleg Bouevitch
  • Publication number: 20100302627
    Abstract: By compensating polarization mode-dispersion as well chromatic dispersion in photonic crystal fiber pulse compressors, high pulse energies can be obtained from all-fiber chirped pulse amplification systems. By inducing third-order dispersion in fiber amplifiers via self-phase modulation, the third-order chromatic dispersion from bulk grating pulse compressors can be compensated and the pulse quality of hybrid fiber/bulk chirped pulse amplification systems can be improved. Finally, by amplifying positively chirped pulses in negative dispersion fiber amplifiers, low noise wavelength tunable seed source via anti-Stokes frequency shifting can be obtained.
    Type: Application
    Filed: August 5, 2010
    Publication date: December 2, 2010
    Inventors: Martin E. FERMANN, Gennady Imeshev, Gyu C. Cho, Zhenlin Liu, Donald J. Harter
  • Publication number: 20100025387
    Abstract: Methods, devices, and systems for ultrashort pulse laser processing of optically transparent materials are disclosed, with example applications in scribing, marking, welding, and joining. For example, ultrashort laser pulses create scribe features with one pass of the laser beam across the material, with at least one of the scribe features being formed below the surface of the material. Slightly modifying the ultrashort pulse laser processing conditions produces sub-surface marks. When properly arranged, these marks are clearly visible with correctly aligned illumination. Reflective marks may also be formed with control of laser parameters. A transparent material other than glass may be utilized. A method for welding transparent materials uses ultrashort laser pulses to create a bond through localized heating.
    Type: Application
    Filed: March 4, 2009
    Publication date: February 4, 2010
    Applicant: IMRA AMERICA, INC.
    Inventors: Alan Y. Arai, Gyu C. Cho, Jingzhou Xu, Fumiyo Yoshino, Haibin Zhang, James Bovatsek, Makoto Yoshida
  • Publication number: 20090097515
    Abstract: The invention describes classes of robust fiber laser systems usable as pulse sources for Nd: or Yb: based regenerative amplifiers intended for industrial settings. The invention modifies adapts and incorporates several recent advances in FCPA systems to use as the input source for this new class of regenerative amplifier.
    Type: Application
    Filed: December 19, 2008
    Publication date: April 16, 2009
    Applicant: IMRA America, Inc
    Inventors: Donald J. HARTER, Gyu C. Cho, Zhenlin Liu, Martin E. Fermann, Xinhua Gu, Salvatore F. Nati, Lawrence Shah, Ingmar Hartl, Mark Bendett
  • Patent number: 7508853
    Abstract: The invention describes classes of robust fiber laser systems usable as pulse sources for Nd: or Yb: based regenerative amplifiers intended for industrial settings. The invention modifies adapts and incorporates several recent advances in FCPA systems to use as the input source for this new class of regenerative amplifier.
    Type: Grant
    Filed: December 7, 2004
    Date of Patent: March 24, 2009
    Assignee: IMRA, America, Inc.
    Inventors: Donald J. Harter, Gyu C. Cho, Zhenlin Liu, Martin E. Fermann, Xinhua Gu, Salvatore F. Nati, Lawrence Shah, Ingmar Hartl, Mark Bendett
  • Publication number: 20080273238
    Abstract: By compensating polarization mode-dispersion as well chromatic dispersion in photonic crystal fiber pulse compressors, high pulse energies can be obtained from all-fiber chirped pulse amplification systems. By inducing third-order dispersion in fiber amplifiers via self-phase modulation, the third-order chromatic dispersion from bulk grating pulse compressors can be compensated and the pulse quality of hybrid fiber/bulk chirped pulse amplification systems can be improved. Finally, by amplifying positively chirped pulses in negative dispersion fiber amplifiers, low noise wavelength tunable seed source via anti-Stokes frequency shifting can be obtained.
    Type: Application
    Filed: July 15, 2008
    Publication date: November 6, 2008
    Inventors: Martin E. Fermann, Gennady Imeshev, Gyu C. Cho, Zhenlin Liu, Donald J. Harter
  • Publication number: 20080240184
    Abstract: A laser head generating ultrashort pulses is integrated with an active beam steering device in the head. Direct linkage with an application system by means of an adequate interface protocol enables the active device to be controlled directly by the application system.
    Type: Application
    Filed: March 27, 2007
    Publication date: October 2, 2008
    Inventors: Gyu C. Cho, Oleg Bouevitch
  • Publication number: 20080232407
    Abstract: An optimized Yb: doped fiber mode-locked oscillator and fiber amplifier system for seeding Nd: or Yb: doped regenerative amplifiers. The pulses are generated in the Yb: or Nd: doped fiber mode-locked oscillator, and may undergo spectral narrowing or broadening, wavelength converting, temporal pulse compression or stretching, pulse attenuation and/or lowering the repetition rate of the pulse train. The conditioned pulses are subsequently coupled into an Yb: or Nd: fiber amplifier. The amplified pulses are stretched before amplification in the regenerative amplifier that is based on an Nd: or Yb: doped solid-state laser material, and then recompressed for output.
    Type: Application
    Filed: June 3, 2008
    Publication date: September 25, 2008
    Inventors: Donald J. HARTER, Gyu C. Cho, Martin E. Fermann, Ingmar Hartl
  • Patent number: 7414780
    Abstract: By compensating polarization mode-dispersion as well chromatic dispersion in photonic crystal fiber pulse compressors, high pulse energies can be obtained from all-fiber chirped pulse amplification systems. By inducing third-order dispersion in fiber amplifiers via self-phase modulation, the third-order chromatic dispersion from bulk grating pulse compressors can be compensated and the pulse quality of hybrid fiber/bulk chirped pulse amplification systems can be improved. Finally, by amplifying positively chirped pulses in negative dispersion fiber amplifiers, low noise wavelength tunable seed source via anti-Stokes frequency shifting can be obtained.
    Type: Grant
    Filed: November 22, 2004
    Date of Patent: August 19, 2008
    Assignee: IMRA America, Inc.
    Inventors: Martin E. Fermann, Gennady Imeshev, Gyu C. Cho, Zhenlin Liu, Donald J. Harter
  • Patent number: 7394591
    Abstract: An optimized Yb: doped fiber mode-locked oscillator and fiber amplifier system for seeding Nd: or Yb: doped regenerative amplifiers. The pulses are generated in the Yb: or Nd: doped fiber mode-locked oscillator, and may undergo spectral narrowing or broadening, wavelength converting, temporal pulse compression or stretching, pulse attenuation and/or lowering the repetition rate of the pulse train. The conditioned pulses are subsequently coupled into an Yb: or Nd: fiber amplifier. The amplified pulses are stretched before amplification in the regenerative amplifier that is based on an Nd: or Yb: doped solid-state laser material, and then recompressed for output.
    Type: Grant
    Filed: October 12, 2004
    Date of Patent: July 1, 2008
    Assignee: IMRA America, Inc.
    Inventors: Donald J. Harter, Gyu C. Cho, Martin E. Fermann, Ingmar Hartl
  • Patent number: 7088756
    Abstract: A modelocked linear fiber laser cavity with enhanced pulse-width control includes concatenated sections of both polarization-maintaining and non-polarization-maintaining fibers. Apodized fiber Bragg gratings and integrated fiber polarizers are included in the cavity to assist in linearly polarizing the output of the cavity. Very short pulses with a large optical bandwidth are obtained by matching the dispersion value of the fiber Bragg grating to the inverse of the dispersion of the intra-cavity fiber.
    Type: Grant
    Filed: July 25, 2003
    Date of Patent: August 8, 2006
    Assignee: Imra America, Inc.
    Inventors: Martin E. Fermann, Gyu C. Cho