Patents by Inventor Donald J. Harter

Donald J. Harter 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: 10256597
    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: February 22, 2017
    Date of Patent: April 9, 2019
    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
  • Patent number: 10197727
    Abstract: Holey fibers provide optical propagation. In various embodiments, a large core holey fiber comprises a cladding region formed by large holes arranged in few layers. The number of layers or rows of holes about the large core can be used to coarse tune the leakage losses of the fundamental and higher modes of a signal, thereby allowing the non-fundamental modes to be substantially eliminated by leakage over a given length of fiber. Fine tuning of leakage losses can be performed by adjusting the hole dimension and/or spacing to yield a desired operation with a desired leakage loss of the fundamental mode. Resulting holey fibers have a large hole dimension and spacing, and thus a large core, when compared to traditional fibers and conventional fibers that propagate a single mode. Other loss mechanisms, such as bend loss and modal spacing can be utilized for selected modes of operation of holey fibers.
    Type: Grant
    Filed: April 11, 2017
    Date of Patent: February 5, 2019
    Assignee: IMRA America, Inc.
    Inventors: Liang Dong, Donald J. Harter, William Wong
  • Patent number: 10014645
    Abstract: System for converting relatively long pulses from rep-rate variable ultrafast optical sources to shorter, high-energy pulses suitable for sources in high-energy ultrafast lasers. Fibers with positive group velocity dispersion (GVD) and self phase modulation are advantageously employed with the optical sources. These systems take advantage of the need for higher pulse energies at lower repetition rates so that such sources can be cost effective.
    Type: Grant
    Filed: November 21, 2016
    Date of Patent: July 3, 2018
    Assignee: IMRA AMERICA, INC.
    Inventor: Donald J. Harter
  • Publication number: 20170343731
    Abstract: Holey fibers provide optical propagation. In various embodiments, a large core holey fiber comprises a cladding region formed by large holes arranged in few layers. The number of layers or rows of holes about the large core can be used to coarse tune the leakage losses of the fundamental and higher modes of a signal, thereby allowing the non-fundamental modes to be substantially eliminated by leakage over a given length of fiber. Fine tuning of leakage losses can be performed by adjusting the hole dimension and/or spacing to yield a desired operation with a desired leakage loss of the fundamental mode. Resulting holey fibers have a large hole dimension and spacing, and thus a large core, when compared to traditional fibers and conventional fibers that propagate a single mode. Other loss mechanisms, such as bend loss and modal spacing can be utilized for selected modes of operation of holey fibers.
    Type: Application
    Filed: April 11, 2017
    Publication date: November 30, 2017
    Inventors: Liang Dong, Donald J. Harter, William Wong
  • Patent number: 9774160
    Abstract: A femtosecond laser based laser processing system having a femtosecond laser, frequency conversion optics, beam manipulation optics, target motion control, processing chamber, diagnostic systems and system control modules. The femtosecond laser based laser processing system allows for the utilization of the unique heat control in micromachining, and the system has greater output beam stability, continuously variable repetition rate and unique temporal beam shaping capabilities.
    Type: Grant
    Filed: August 27, 2015
    Date of Patent: September 26, 2017
    Assignee: IMRA AMERICA, INC.
    Inventor: Donald J. Harter
  • Publication number: 20170179676
    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: February 22, 2017
    Publication date: June 22, 2017
    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: 9680280
    Abstract: An electronic circuit for controlling a laser system consisting of a pulse source and high power fiber amplifier is disclosed. The circuit is used to control the gain of the high power fiber amplifier system so that the amplified output pulses have predetermined pulse energy as the pulse width and repetition rate of the oscillator are varied. This includes keeping the pulse energy constant when the pulse train is turned on. The circuitry is also used to control the temperature of the high power fiber amplifier pump diode such that the wavelength of the pump diode is held at the optimum absorption wavelength of the fiber amplifier as the diode current is varied. The circuitry also provides a means of protecting the high power fiber amplifier from damage due to a loss of signal from the pulse source or from a pulse-source signal of insufficient injection energy.
    Type: Grant
    Filed: August 15, 2013
    Date of Patent: June 13, 2017
    Assignee: IMRA AMERICA, INC.
    Inventors: Salvatore F. Nati, Otho E. Ulrich, Jr., Gyu C. Cho, Wayne A. Gillis, Donald J. Harter, Mark Bendett, Ingmar Hartl
  • Patent number: 9645309
    Abstract: Holey fibers provide optical propagation. In various embodiments, a large core holey fiber comprises a cladding region formed by large holes arranged in few layers. The number of layers or rows of holes about the large core can be used to coarse tune the leakage losses of the fundamental and higher modes of a signal, thereby allowing the non-fundamental modes to be substantially eliminated by leakage over a given length of fiber. Fine tuning of leakage losses can be performed by adjusting the hole dimension and/or spacing to yield a desired operation with a desired leakage loss of the fundamental mode. Resulting holey fibers have a large hole dimension and spacing, and thus a large core, when compared to traditional fibers and conventional fibers that propagate a single mode. Other loss mechanisms, such as bend loss and modal spacing can be utilized for selected modes of operation of holey fibers.
    Type: Grant
    Filed: September 29, 2014
    Date of Patent: May 9, 2017
    Assignee: IMRA America, Inc.
    Inventors: Liang Dong, Donald J. Harter, William Wong
  • Publication number: 20170077669
    Abstract: System for converting relatively long pulses from rep-rate variable ultrafast optical sources to shorter, high-energy pulses suitable for sources in high-energy ultrafast lasers. Fibers with positive group velocity dispersion (GVD) and self phase modulation are advantageously employed with the optical sources. These systems take advantage of the need for higher pulse energies at lower repetition rates so that such sources can be cost effective.
    Type: Application
    Filed: November 21, 2016
    Publication date: March 16, 2017
    Applicant: IMRA AMERICA, INC.
    Inventor: Donald J. HARTER
  • Patent number: 9595802
    Abstract: A laser utilizes a cavity design which allows the stable generation of high peak power pulses from mode-locked multi-mode fiber lasers, greatly extending the peak power limits of conventional mode-locked single-mode fiber lasers. Mode-locking may be induced by insertion of a saturable absorber into the cavity and by inserting one or more mode-filters to ensure the oscillation of the fundamental mode in the multi-mode fiber. The probability of damage of the absorber may be minimized by the insertion of an additional semiconductor optical power limiter into the cavity.
    Type: Grant
    Filed: March 24, 2014
    Date of Patent: March 14, 2017
    Assignee: IMRA America, Inc.
    Inventors: Martin E. Fermann, Donald J. Harter
  • Patent number: 9590386
    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: September 10, 2014
    Date of Patent: March 7, 2017
    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
  • Patent number: 9570880
    Abstract: A laser utilizes a cavity design which allows the stable generation of high peak power pulses from mode-locked multi-mode fiber lasers, greatly extending the peak power limits of conventional mode-locked single-mode fiber lasers. Mode-locking may be induced by insertion of a saturable absorber into the cavity and by inserting one or more mode-filters to ensure the oscillation of the fundamental mode in the multi-mode fiber. The probability of damage of the absorber may be minimized by the insertion of an additional semiconductor optical power limiter into the cavity.
    Type: Grant
    Filed: February 6, 2014
    Date of Patent: February 14, 2017
    Assignee: IMRA America, Inc.
    Inventors: Martin E. Fermann, Donald J. Harter
  • Patent number: 9553417
    Abstract: System for converting relatively long pulses from rep-rate variable ultrafast optical sources to shorter, high-energy pulses suitable for sources in high-energy ultrafast lasers. Fibers with positive group velocity dispersion (GVD) and self phase modulation are advantageously employed with the optical sources. These systems take advantage of the need for higher pulse energies at lower repetition rates so that such sources can be cost effective.
    Type: Grant
    Filed: October 17, 2013
    Date of Patent: January 24, 2017
    Assignee: IMRA AMERICA, INC.
    Inventor: Donald J. Harter
  • Publication number: 20160322771
    Abstract: System for converting relatively long pulses from rep-rate variable ultrafast optical sources to shorter, high-energy pulses suitable for sources in high-energy ultrafast lasers. Fibers with positive group velocity dispersion (GVD) and self phase modulation are advantageously employed with the optical sources. These systems take advantage of the need for higher pulse energies at lower repetition rates so that such sources can be cost effective.
    Type: Application
    Filed: October 17, 2013
    Publication date: November 3, 2016
    Applicant: IMRA AMERICA, INC.
    Inventor: Donald J. HARTER
  • Publication number: 20160164247
    Abstract: A laser utilizes a cavity design which allows the stable generation of high peak power pulses from mode-locked multi-mode fiber lasers, greatly extending the peak power limits of conventional mode-locked single-mode fiber lasers. Mode-locking may be induced by insertion of a saturable absorber into the cavity and by inserting one or more mode-filters to ensure the oscillation of the fundamental mode in the multi-mode fiber. The probability of damage of the absorber may be minimized by the insertion of an additional semiconductor optical power limiter into the cavity.
    Type: Application
    Filed: March 24, 2014
    Publication date: June 9, 2016
    Applicant: IMRA America, Inc.
    Inventors: Martin E. Fermann, Donald J. Harter
  • Publication number: 20150372445
    Abstract: A femtosecond laser based laser processing system having a femtosecond laser, frequency conversion optics, beam manipulation optics, target motion control, processing chamber, diagnostic systems and system control modules. The femtosecond laser based laser processing system allows for the utilization of the unique heat control in micromachining, and the system has greater output beam stability, continuously variable repetition rate and unique temporal beam shaping capabilities.
    Type: Application
    Filed: August 27, 2015
    Publication date: December 24, 2015
    Applicant: IMRA AMERICA, INC.
    Inventor: Donald J. HARTER
  • Patent number: 9147989
    Abstract: A femtosecond laser based laser processing system having a femtosecond laser, frequency conversion optics, beam manipulation optics, target motion control, processing chamber, diagnostic systems and system control modules. The femtosecond laser based laser processing system allows for the utilization of the unique heat control in micromachining, and the system has greater output beam stability, continuously variable repetition rate and unique temporal beam shaping capabilities.
    Type: Grant
    Filed: December 9, 2013
    Date of Patent: September 29, 2015
    Assignee: IMRA AMERICA, INC.
    Inventors: Lawrence Shah, James M. Bovatsek, Alan Y. Arai, Tadashi Yamamoto, Rajesh S. Patel, Donald J. Harter
  • Publication number: 20150255942
    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, a low noise wavelength tunable seed source via anti-Stokes frequency shifting can be obtained.
    Type: Application
    Filed: May 19, 2015
    Publication date: September 10, 2015
    Applicant: IMRA AMERICA, INC.
    Inventors: Martin E. FERMANN, Gennady IMESHEV, Gyu C. CHO, Zhenlin LIU, Donald J. HARTER
  • Patent number: 9042004
    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, a low noise wavelength tunable seed source via anti-Stokes frequency shifting can be obtained.
    Type: Grant
    Filed: July 8, 2013
    Date of Patent: May 26, 2015
    Assignee: IMRA AMERICA, INC.
    Inventors: Martin E. Fermann, Gennady Imeshev, Gyu C. Cho, Zhenlin Liu, Donald J. Harter
  • Publication number: 20150036701
    Abstract: Holey fibers provide optical propagation. In various embodiments, a large core holey fiber comprises a cladding region formed by large holes arranged in few layers. The number of layers or rows of holes about the large core can be used to coarse tune the leakage losses of the fundamental and higher modes of a signal, thereby allowing the non-fundamental modes to be substantially eliminated by leakage over a given length of fiber. Fine tuning of leakage losses can be performed by adjusting the hole dimension and/or spacing to yield a desired operation with a desired leakage loss of the fundamental mode. Resulting holey fibers have a large hole dimension and spacing, and thus a large core, when compared to traditional fibers and conventional fibers that propagate a single mode. Other loss mechanisms, such as bend loss and modal spacing can be utilized for selected modes of operation of holey fibers.
    Type: Application
    Filed: September 29, 2014
    Publication date: February 5, 2015
    Inventors: Liang Dong, Donald J. Harter, William Wong