Patents by Inventor Gyu Cheon Cho
Gyu Cheon 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).
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Patent number: 11201447Abstract: Chirped pulse amplification (CPA) systems configured to generate and amplify multi-pulses are described. The nonlinear interaction of pulses can generate a multiple pulse pack with a dense time separation between pulses. Reducing or eliminating the nonlinear interaction can be provided by spectrally and/or temporally splitting pulses in the chirped amplification system.Type: GrantFiled: December 17, 2019Date of Patent: December 14, 2021Assignee: IMRA AMERICA, INC.Inventors: Jingzhou Xu, Takashi Hori, Shigeru Suzuki, Gyu Cheon Cho
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Publication number: 20200127431Abstract: Chirped pulse amplification (CPA) systems configured to generate and amplify multi-pulses are described. The nonlinear interaction of pulses can generate a multiple pulse pack with a dense time separation between pulses. Reducing or eliminating the nonlinear interaction can be provided by spectrally and/or temporally splitting pulses in the chirped amplification system.Type: ApplicationFiled: December 17, 2019Publication date: April 23, 2020Inventors: Jingzhou Xu, Takashi Hori, Shigeru Suzuki, Gyu Cheon Cho
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Patent number: 9640940Abstract: A pulsed laser comprises an oscillator and amplifier. An attenuator and/or pre-compressor may be disposed between the oscillator and amplifier to improve performance and possibly the quality of pulses output from the laser. Such pre-compression may be implemented with spectral filters and/or dispersive elements between the oscillator and amplifier. The pulsed laser may have a modular design comprising modular devices that may have Telcordia-graded quality and reliability. Fiber pigtails extending from the device modules can be spliced together to form laser system. In one embodiment, a laser system operating at approximately 1050 nm comprises an oscillator having a spectral bandwidth of approximately 19 nm. This oscillator signal can be manipulated to generate a pulse having a width below approximately 90 fs. A modelocked linear fiber laser cavity with enhanced pulse-width control includes concatenated sections of both polarization-maintaining and non-polarization-maintaining fibers.Type: GrantFiled: April 13, 2015Date of Patent: May 2, 2017Assignee: IMRA America, Inc.Inventors: Xinhua Gu, Mark Bendett, Gyu Cheon Cho, Martin E. Fermann
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Patent number: 9321126Abstract: Various embodiments may be used for laser-based modification of target material of a workpiece while advantageously achieving improvements in processing throughput and/or quality. Embodiments of a method of processing may include focusing and directing laser pulses to a region of the workpiece at a pulse width sufficiently short so that material is efficiently removed by nonlinear optical absorption from the region and a quantity of heat affected zone and thermal stress on the material within the region, proximate to the region, or both is reduced relative to a quantity obtainable using a laser with longer pulses. In at least one embodiment, an ultrashort pulse laser system may include at least one of a fiber amplifier or fiber laser. Various embodiments are suitable for at least one of dicing, cutting, scribing, and forming features on or within a composite material.Type: GrantFiled: March 1, 2011Date of Patent: April 26, 2016Assignee: IMRA America, Inc.Inventors: Jingzhou Xu, Jin Young Sohn, Gyu Cheon Cho, Lawrence Shah
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Patent number: 9240670Abstract: In at least one embodiment time separated pulse pairs are generated, followed by amplification to increase the available peak and/or average power. The pulses are characterized by a time separation that exceeds the input pulse width and with distinct polarization states. The time and polarization discrimination allows easy extraction of the pulses after amplification. In some embodiments polarization maintaining (PM) fibers and/or amplifiers are utilized which provides a compact arrangement. At least one implementation provides for seeding of a solid state amplifier or large core fiber amplifier with time delayed, polarization split pulses, with capability for recombining the time separated pulses at an amplifier output. In various implementations suitable combinations of bulk optics and fibers may be utilized. In some implementations wavelength converted pulse trains are generated.Type: GrantFiled: March 6, 2012Date of Patent: January 19, 2016Assignee: IMRA AMERICA, INC.Inventors: Jingzhou Xu, Gyu Cheon Cho
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Publication number: 20150325977Abstract: A pulsed laser comprises an oscillator and amplifier. An attenuator and/or pre-compressor may be disposed between the oscillator and amplifier to improve performance and possibly the quality of pulses output from the laser. Such pre-compression may be implemented with spectral filters and/or dispersive elements between the oscillator and amplifier. The pulsed laser may have a modular design comprising modular devices that may have Telcordia-graded quality and reliability. Fiber pigtails extending from the device modules can be spliced together to form laser system. In one embodiment, a laser system operating at approximately 1050 nm comprises an oscillator having a spectral bandwidth of approximately 19 nm. This oscillator signal can be manipulated to generate a pulse having a width below approximately 90 fs. A modelocked linear fiber laser cavity with enhanced pulse-width control includes concatenated sections of both polarization-maintaining and non-polarization-maintaining fibers.Type: ApplicationFiled: April 13, 2015Publication date: November 12, 2015Inventors: Xinhua Gu, Mark Bendett, Gyu Cheon Cho, Martin E. Fermann
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Patent number: 9071037Abstract: A pulsed laser comprises an oscillator and amplifier. An attenuator and/or pre-compressor may be disposed between the oscillator and amplifier to improve performance and possibly the quality of pulses output from the laser. Such pre-compression may be implemented with spectral filters and/or dispersive elements between the oscillator and amplifier. The pulsed laser may have a modular design comprising modular devices that may have Telcordia-graded quality and reliability. Fiber pigtails extending from the device modules can be spliced together to form laser system. In one embodiment, a laser system operating at approximately 1050 nm comprises an oscillator having a spectral bandwidth of approximately 19 nm. This oscillator signal can be manipulated to generate a pulse having a width below approximately 90 fs. A modelocked linear fiber laser cavity with enhanced pulse-width control includes concatenated sections of both polarization-maintaining and non-polarization-maintaining fibers.Type: GrantFiled: August 28, 2013Date of Patent: June 30, 2015Assignee: IMRA America, Inc.Inventors: Xinhua Gu, Mark Bendett, Gyu Cheon Cho, Martin E. Fermann
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Publication number: 20150136744Abstract: Examples of methods and systems for laser processing of materials are disclosed. Methods and systems for singulation of a wafer comprising a coated substrate can utilize a laser outputting light that has a wavelength that is transparent to the wafer substrate but which may not be transparent to the coating layer(s). Using techniques for managing fluence and focal condition of the laser beam, the coating layer(s) and the substrate material can be processed through ablation and internal modification, respectively. The internal modification can result in die separation.Type: ApplicationFiled: January 28, 2015Publication date: May 21, 2015Inventors: Alan Y. Arai, Gyu Cheon Cho, Jingzhou Xu
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Publication number: 20150085885Abstract: A pulsed laser comprises an oscillator and amplifier. An attenuator and/or pre-compressor may be disposed between the oscillator and amplifier to improve performance and possibly the quality of pulses output from the laser. Such pre-compression may be implemented with spectral filters and/or dispersive elements between the oscillator and amplifier. The pulsed laser may have a modular design comprising modular devices that may have Telcordia-graded quality and reliability. Fiber pigtails extending from the device modules can be spliced together to form laser system. In one embodiment, a laser system operating at approximately 1050 nm comprises an oscillator having a spectral bandwidth of approximately 19 nm. This oscillator signal can be manipulated to generate a pulse having a width below approximately 90 fs. A modelocked linear fiber laser cavity with enhanced pulse-width control includes concatenated sections of both polarization-maintaining and non-polarization-maintaining fibers.Type: ApplicationFiled: August 28, 2013Publication date: March 26, 2015Applicant: IMRA America, Inc.Inventors: Xinhua Gu, Mark Bendett, Gyu Cheon Cho, Martin E. Fermann
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Patent number: 8969220Abstract: Examples of methods and systems for laser processing of materials are disclosed. Methods and systems for singulation of a wafer comprising a coated substrate can utilize a laser outputting light that has a wavelength that is transparent to the wafer substrate but which may not be transparent to the coating layer(s). Using techniques for managing fluence and focal condition of the laser beam, the coating layer(s) and the substrate material can be processed through ablation and internal modification, respectively. The internal modification can result in die separation.Type: GrantFiled: December 14, 2012Date of Patent: March 3, 2015Assignee: IMRA America, Inc.Inventors: Alan Y. Arai, Gyu Cheon Cho, Jingzhou Xu
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Publication number: 20140312469Abstract: Various embodiments may be used for laser-based modification of target material of a workpiece while advantageously achieving improvements in processing throughput and/or quality. Embodiments of a method of processing may include focusing and directing laser pulses to a region of the workpiece at a pulse repetition rate sufficiently high so that material is efficiently removed from the region and a quantity of unwanted material within the region, proximate to the region, or both is reduced relative to a quantity obtainable at a lower repetition rate. Embodiments of an ultrashort pulse laser system may include a fiber amplifier or fiber laser. Various embodiments are suitable for at least one of dicing, cutting, scribing, and forming features on or within a semiconductor substrate. Workpiece materials may include metals, inorganic or organic dielectrics, or any material to be micromachined with femtosecond, picosecond, and/or nanosecond pulses.Type: ApplicationFiled: June 30, 2014Publication date: October 23, 2014Inventors: Lawrence Shah, Gyu Cheon Cho, Jingzhou Xu
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Patent number: 8785813Abstract: Various embodiments may be used for laser-based modification of target material of a workpiece while advantageously achieving improvements in processing throughput and/or quality. Embodiments of a method of processing may include focusing and directing laser pulses to a region of the workpiece at a pulse repetition rate sufficiently high so that material is efficiently removed from the region and a quantity of unwanted material within the region, proximate to the region, or both is reduced relative to a quantity obtainable at a lower repetition rate. Embodiments of an ultrashort pulse laser system may include a fiber amplifier or fiber laser. Various embodiments are suitable for at least one of dicing, cutting, scribing, and forming features on or within a semiconductor substrate. Workpiece materials may include metals, inorganic or organic dielectrics, or any material to be micromachined with femtosecond, picosecond, and/or nanosecond pulses.Type: GrantFiled: March 15, 2012Date of Patent: July 22, 2014Assignee: IMRA America, Inc.Inventors: Lawrence Shah, Gyu Cheon Cho, Jingzhou Xu
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Patent number: 8537459Abstract: 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: GrantFiled: April 30, 2012Date of Patent: September 17, 2013Assignee: IMRA America, Inc.Inventors: Salvatore F. Nati, Otho E. Ulrich, Jr., Gyu Cheon Cho, Wayne A. Gillis, Donald J. Harter, Mark Bendett, Ingmar Hartl
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Patent number: 8537864Abstract: A pulsed laser comprises an oscillator and amplifier. An attenuator and/or pre-compressor may be disposed between the oscillator and amplifier to improve performance and possibly the quality of pulses output from the laser. Such pre-compression may be implemented with spectral filters and/or dispersive elements between the oscillator and amplifier. The pulsed laser may have a modular design comprising modular devices that may have Telcordia-graded quality and reliability. Fiber pigtails extending from the device modules can be spliced together to form laser system. In one embodiment, a laser system operating at approximately 1050 nm comprises an oscillator having a spectral bandwidth of approximately 19 nm. This oscillator signal can be manipulated to generate a pulse having a width below approximately 90 fs.Type: GrantFiled: June 14, 2010Date of Patent: September 17, 2013Assignee: IMRA America, Inc.Inventors: Xinhua Gu, Mark Bendett, Gyu Cheon Cho
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Publication number: 20130064256Abstract: In at least one embodiment a laser system includes a fiber laser source, a polarization controller and a wavelength converter. The relative power distribution between a pump wavelength and a signal wavelength is controllable using the polarization controller. An optional phase compensator is used to control polarization state of the output laser beam. In various embodiments the relative power distribution among multiple wavelengths may be controlled over a range of at least about 100:1.Type: ApplicationFiled: September 12, 2012Publication date: March 14, 2013Applicant: IMRA AMERICA, INC.Inventors: Jingzhou XU, Gyu Cheon CHO
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Publication number: 20120230353Abstract: In at least one embodiment time separated pulse pairs are generated, followed by amplification to increase the available peak and/or average power. The pulses are characterized by a time separation that exceeds the input pulse width and with distinct polarization states. The time and polarization discrimination allows easy extraction of the pulses after amplification. In some embodiments polarization maintaining (PM) fibers and/or amplifiers are utilized which provides a compact arrangement. At least one implementation provides for seeding of a solid state amplifier or large core fiber amplifier with time delayed, polarization split pulses, with capability for recombining the time separated pulses at an amplifier output. In various implementations suitable combinations of bulk optics and fibers may be utilized. In some implementations wavelength converted pulse trains are generated.Type: ApplicationFiled: March 6, 2012Publication date: September 13, 2012Applicant: IMRA AMERICA, INC.Inventors: Jingzhou XU, Gyu Cheon CHO
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Publication number: 20120212803Abstract: 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: ApplicationFiled: April 30, 2012Publication date: August 23, 2012Applicant: IMRA AMERICA, INC.Inventors: Salvatore F. NATI, Otho E. ULRICH, JR., Gyu Cheon CHO, Wayne A. GILLIS, Donald J. HARTER, Mark BENDETT, Ingmar HARTL
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Publication number: 20120195330Abstract: Methods and systems for delivery of high peak power optical pulses through optical fiber are disclosed. Raman soliton generation is utilized to maintain the properties of the pulses in the delivery fiber. The apparatus can comprise any high peak power pulse source and delivery fiber supporting Raman soliton generation.Type: ApplicationFiled: January 25, 2012Publication date: August 2, 2012Applicant: IMRA AMERICA, INC.Inventors: Gyu Cheon CHO, Jingzhou XU
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Publication number: 20120196454Abstract: Various embodiments may be used for laser-based modification of target material of a workpiece while advantageously achieving improvements in processing throughput and/or quality. Embodiments of a method of processing may include focusing and directing laser pulses to a region of the workpiece at a pulse repetition rate sufficiently high so that material is efficiently removed from the region and a quantity of unwanted material within the region, proximate to the region, or both is reduced relative to a quantity obtainable at a lower repetition rate. Embodiments of an ultrashort pulse laser system may include a fiber amplifier or fiber laser. Various embodiments are suitable for at least one of dicing, cutting, scribing, and forming features on or within a semiconductor substrate. Workpiece materials may include metals, inorganic or organic dielectrics, or any material to be micromachined with femtosecond, picosecond, and/or nanosecond pulses.Type: ApplicationFiled: March 15, 2012Publication date: August 2, 2012Applicant: IMRA AMERICA, INC.Inventors: Lawrence Shah, Gyu Cheon Cho, Jingzhou Xu
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Patent number: 8158493Abstract: Various embodiments may be used for laser-based modification of target material of a workpiece while advantageously achieving improvements in processing throughput and/or quality. Embodiments of a method of processing may include focusing and directing laser pulses to a region of the workpiece at a pulse repetition rate sufficiently high so that material is efficiently removed from the region and a quantity of unwanted material within the region, proximate to the region, or both is reduced relative to a quantity obtainable at a lower repetition rate. Embodiments of an ultrashort pulse laser system may include at least one of a fiber amplifier or fiber laser. Various embodiments are suitable for at least one of dicing, cutting, scribing, and forming features on or within a semiconductor substrate. Workpiece materials may also include metals, inorganic or organic dielectrics, or any material to be micromachined with femtosecond, picosecond, and/or nanosecond pulses.Type: GrantFiled: December 17, 2009Date of Patent: April 17, 2012Assignee: IMRA America, Inc.Inventors: Lawrence Shah, Gyu Cheon Cho, Jingzhou Xu