Patents by Inventor Tiequn Qiu
Tiequn Qiu 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: 11624614Abstract: Systems and methods for reducing rotation sensing errors from laser source signal and modulation cross-talk are provided herein. An RFOG includes a fiber optic resonator; a first laser source that produces a first light wave at a first carrier frequency and a first cross-talked portion at a second carrier frequency wave for propagating in a first direction, wherein a second cross-talked portion propagates in a second direction that is opposite to the first direction; a second laser source that produces a second light wave for propagating in the second direction at a second carrier frequency, and having a third cross-talked portion that propagates in the first direction, a first modulator that modulates the first light wave by suppressing light at the first carrier frequency and the second cross-talked portion at the second carrier frequency, and photodetectors that generate signals from the modulated first light wave and the second light wave.Type: GrantFiled: August 4, 2020Date of Patent: April 11, 2023Assignee: Honeywell International Inc.Inventors: Lee K. Strandjord, Tiequn Qiu, Glen A. Sanders
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Publication number: 20230097179Abstract: Systems and methods for reducing rotation sensing errors from laser source signal and modulation cross-talk are provided herein. An RFOG includes a fiber optic resonator; a first laser source that produces a first light wave at a first carrier frequency and a first cross-talked portion at a second carrier frequency wave for propagating in a first direction, wherein a second cross-talked portion propagates in a second direction that is opposite to the first direction; a second laser source that produces a second light wave for propagating in the second direction at a second carrier frequency, and having a third cross-talked portion that propagates in the first direction, a first modulator that modulates the first light wave by suppressing light at the first carrier frequency and the second cross-talked portion at the second carrier frequency, and photodetectors that generate signals from the modulated first light wave and the second light wave.Type: ApplicationFiled: August 4, 2020Publication date: March 30, 2023Applicant: Honeywell International Inc.Inventors: Lee K. Strandjord, Tiequn Qiu, Glen A. Sanders
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Patent number: 11476633Abstract: Systems and methods for ring laser gyroscopes (RLGs) are provided. An RLG includes a traveling-wave resonator cavity with three or more mirrors and a gain medium positioned in the traveling-wave resonator cavity between two of the three or more mirrors. The gain medium is a solid-state gain medium or a nonlinear optical medium. The RLG further includes a first pump laser and a second pump laser to pump the gain medium in different directions and generate first and second lasing signals that traverse the traveling-wave resonator cavity in a opposite directions. The RLG further includes first and second photodetectors to measure levels of the first and second lasing signals. The RLG further includes at least one processor configured to adjust a power level of the first pump laser and/or a power level of the second pump laser based on the measured power levels of the first and second lasing signals.Type: GrantFiled: July 20, 2020Date of Patent: October 18, 2022Assignee: Honeywell International Inc.Inventors: Tiequn Qiu, Teresa Marta, Jianfeng Wu
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Publication number: 20220021177Abstract: Systems and methods for ring laser gyroscopes (RLGs) are provided. An RLG includes a traveling-wave resonator cavity with three or more mirrors and a gain medium positioned in the traveling-wave resonator cavity between two of the three or more mirrors. The gain medium is a solid-state gain medium or a nonlinear optical medium. The RLG further includes a first pump laser and a second pump laser to pump the gain medium in different directions and generate first and second lasing signals that traverse the traveling-wave resonator cavity in a opposite directions. The RLG further includes first and second photodetectors to measure levels of the first and second lasing signals. The RLG further includes at least one processor configured to adjust a power level of the first pump laser and/or a power level of the second pump laser based on the measured power levels of the first and second lasing signals.Type: ApplicationFiled: July 20, 2020Publication date: January 20, 2022Applicant: Honeywell International Inc.Inventors: Tiequn Qiu, Teresa Marta, Jianfeng Wu
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Patent number: 11002545Abstract: Systems and methods for performing SHD switching for RFOGS are provided herein. A system includes a resonator in which light resonates; at least one laser source that produces first and second optical beams; heterodyne modulators that modulate the first and second optical beams at a heterodyne frequency plus a modulation frequency offset to produce multiple sideband optical beams, wherein the modulation frequency offset has a different sign for the first and second optical beams; a frequency switching controller that alternatingly switches the signs of the modulation frequency offset applied to the first and second optical beams, wherein the heterodyne modulation of the first and second optical beams are on average at the heterodyne frequency; at least one coupler that couples the sideband optical beams into the resonator; a feedback control that detects the sideband optical beams transmitted from the resonator and, in response, adjusts frequencies of the optical beams.Type: GrantFiled: August 20, 2019Date of Patent: May 11, 2021Assignee: Honeywell International Inc.Inventors: Lee K. Strandjord, Glen A. Sanders, Jianfeng Wu, Tiequn Qiu, Marc Smiciklas
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Publication number: 20210055108Abstract: Systems and methods for performing SHD switching for RFOGS are provided herein. A system includes a resonator in which light resonates; at least one laser source that produces first and second optical beams; heterodyne modulators that modulate the first and second optical beams at a heterodyne frequency plus a modulation frequency offset to produce multiple sideband optical beams, wherein the modulation frequency offset has a different sign for the first and second optical beams; a frequency switching controller that alternatingly switches the signs of the modulation frequency offset applied to the first and second optical beams, wherein the heterodyne modulation of the first and second optical beams are on average at the heterodyne frequency; at least one coupler that couples the sideband optical beams into the resonator; a feedback control that detects the sideband optical beams transmitted from the resonator and, in response, adjusts frequencies of the optical beams.Type: ApplicationFiled: August 20, 2019Publication date: February 25, 2021Applicant: Honeywell International Inc.Inventors: Lee K. Strandjord, Glen A. Sanders, Jianfeng Wu, Tiequn Qiu, Marc Smiciklas
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Patent number: 10914587Abstract: Techniques are provided for correcting for time varying changes to a gyroscope incorporating a resonator and/or to an environment in which the gyroscope is located, and which affect the resonator. Free spectral range of the gyroscope, which varies with such changes, is determined and is used to correct at least one of gyroscope bias and scale factor.Type: GrantFiled: July 23, 2019Date of Patent: February 9, 2021Assignee: Honeywell International Inc.Inventors: Glen A. Sanders, Lee K. Strandjord, Tiequn Qiu, Marc Smiciklas, Norman Gerard Tarleton
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Publication number: 20210025709Abstract: Techniques are provided for correcting for time varying changes to a gyroscope incorporating a resonator and/or to an environment in which the gyroscope is located, and which affect the resonator. Free spectral range of the gyroscope, which varies with such changes, is determined and is used to correct at least one of gyroscope bias and scale factor.Type: ApplicationFiled: July 23, 2019Publication date: January 28, 2021Applicant: Honeywell International Inc.Inventors: Glen A. Sanders, Lee K. Strandjord, Tiequn Qiu, Marc Smiciklas, Norman Gerard Tarleton
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Publication number: 20200388984Abstract: A micro femtosecond laser with reduced radiation and temperature sensitivity is provided. The laser includes a housing with a radiation shield. Optical components that include a micro gain element are received within the housing. An input end of a pump light delivering fiber is positioned outside the housing. An output end of the pump light delivering fiber is positioned within the housing to deliver input beams to the optical components. A light signal generating pump is used to generate the input beams that are communicated to the input end of the pump light delivering fiber. A first end of a hollow core fiber is positioned within the housing to be in optical communication with the optical components. A second end of the hollow core fiber is positioned outside the housing. A partially reflective output coupling mirror is in optical communication with the second end of the hollow core fiber.Type: ApplicationFiled: June 7, 2019Publication date: December 10, 2020Applicant: Honeywell International Inc.Inventors: Tiequn Qiu, Chellappan Narayanan, Jeffrey Earl Lewis, Sorin Mosor
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Publication number: 20200220319Abstract: In an example, a mode-locked laser includes a resonator cavity having a saturable absorber, a hollow core fiber coupled to the saturable absorber, and an optical amplifier optically coupled between the hollow core fiber and an output coupler. The mode-locked laser further includes a first pump laser and a wavelength division multiplexer coupled to the first pump laser. The wavelength division multiplexer is configured to couple light from the first pump laser into the resonator cavity to pump the optical amplifier. The mode-locked laser is configured to generate a pulse waveform at a repetition rate of approximately 100 MHz to 200 MHz.Type: ApplicationFiled: January 9, 2019Publication date: July 9, 2020Applicant: Honeywell International Inc.Inventors: Chellappan Narayanan, Jeffrey Earl Lewis, Sorin Mosor, Tiequn Qiu
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Patent number: 10627654Abstract: An acousto-optic waveguide device comprises a substrate comprising a first material having a first refractive index and a first acoustic velocity; a cladding layer over the substrate, the cladding layer comprising a second material having a second refractive index that is distinct from the first refractive index, the second material having a second acoustic velocity that is distinct from the first acoustic velocity; and an optical core surrounded by the cladding layer, the optical core comprising a third material having a third refractive index that is higher that the first refractive index and the second refractive index, the third material having a third acoustic velocity that is distinct from the first acoustic velocity and the second acoustic velocity. The cladding layer that surrounds the optical core has a thickness configured to substantially confine acoustic waves to the cladding layer when an optical signal propagates through the optical core.Type: GrantFiled: March 18, 2019Date of Patent: April 21, 2020Assignee: Honeywell International Inc.Inventors: Matthew Wade Puckett, Jianfeng Wu, Mary Salit, Tiequn Qiu
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Publication number: 20200096698Abstract: An acousto-optic waveguide device comprises a substrate comprising a first material having a first refractive index and a first acoustic velocity; a cladding layer over the substrate, the cladding layer comprising a second material having a second refractive index that is distinct from the first refractive index, the second material having a second acoustic velocity that is distinct from the first acoustic velocity; and an optical core surrounded by the cladding layer, the optical core comprising a third material having a third refractive index that is higher that the first refractive index and the second refractive index, the third material having a third acoustic velocity that is distinct from the first acoustic velocity and the second acoustic velocity. The cladding layer that surrounds the optical core has a thickness configured to substantially confine acoustic waves to the cladding layer when an optical signal propagates through the optical core.Type: ApplicationFiled: March 18, 2019Publication date: March 26, 2020Applicant: Honeywell International Inc.Inventors: Matthew Wade Puckett, Jianfeng Wu, Mary Salit, Tiequn Qiu
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Publication number: 20200072609Abstract: A method is provided. The method comprises: receiving a first optical signal and a second optical signal; injecting the first optical signal into an optical resonator so that the first optical signal propagates in a first direction through the optical resonator; injecting the second optical signal into the optical resonator so that the second optical signal propagates in a second direction through the optical resonator, which is opposite to the first direction; filtering an optical signal propagating in the first direction of the optical resonator with a first common polarizer having the first polarization; and filtering an optical signal propagating in the second direction of the optical resonator with the first common polarizer.Type: ApplicationFiled: September 4, 2018Publication date: March 5, 2020Applicant: Honeywell International Inc.Inventors: Neil A. Krueger, Tiequn Qiu, Lee K. Strandjord, Glen A. Sanders
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Patent number: 10578722Abstract: In one embodiment, a method of operating a glare reduction and ranging optical system having an image sensor with pixels is provided.Type: GrantFiled: May 24, 2017Date of Patent: March 3, 2020Assignee: Honeywell International Inc.Inventors: Jianfeng Wu, Matthew Wade Puckett, Tiequn Qiu, Glen A. Sanders
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Patent number: 10415971Abstract: Bias error in a resonant fiber optic gyroscope (RFOG) is diminished by reducing polarization mismatch between a polarization Eigenstate of optical signals propagating inside of a resonator of the RFOG and the polarization of optical signals being injected into the resonator of the RFOG. The polarization mismatch is reduced by filtering the optical signals circulating in the resonator and the optical signals injected into the resonator with common polarizers.Type: GrantFiled: January 15, 2018Date of Patent: September 17, 2019Assignee: Honeywell International Inc.Inventors: Neil Krueger, Mary Salit, Barbara Vizenor, Glen A. Sanders, Lee K. Strandjord, Tiequn Qiu
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Patent number: 10365107Abstract: Systems and methods for reducing polarization-related bias errors in RFOGS are described herein. In certain implementations, an RFOG system includes a fiber optic resonator, one or more laser sources, wherein light from the laser sources launches first and second optical beams into the fiber optic resonator in opposite directions, and an electro-optically tunable devices in the resonator path configured to modulate the phase difference between polarization components in the first and second optical beams as the optical beams propagate within the fiber optic resonator. The system further includes at least one photodetector, wherein the polarization components of the first and second optical beams are incident on the photodetector, wherein the at least one photodetector provides an electrical signal, and at least one processing unit configured to receive the electrical signal and calculate a rotation rate for the RFOG and provide a drive signal for the electro-optically tunable device.Type: GrantFiled: August 3, 2017Date of Patent: July 30, 2019Assignee: Honeywell International Inc.Inventors: Glen A. Sanders, Marc Smiciklas, Tiequn Qiu, Jianfeng Wu, Lee K. Strandjord
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Publication number: 20190219396Abstract: Bias error in a resonant fiber optic gyroscope (RFOG) is diminished by reducing polarization mismatch between a polarization Eigenstate of optical signals propagating inside of a resonator of the RFOG and the polarization of optical signals being injected into the resonator of the RFOG. The polarization mismatch is reduced by filtering the optical signals circulating in the resonator and the optical signals injected into the resonator with common polarizers.Type: ApplicationFiled: January 15, 2018Publication date: July 18, 2019Inventors: Neil Krueger, Mary Salit, Barbara Vizenor, Glen A. Sanders, Lee K. Strandjord, Tiequn Qiu
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Patent number: 10288429Abstract: In one embodiment, a method is provided. The method comprises transmitting a first laser pump signal to an optical resonator; adjusting a frequency of the first laser pump signal; generating a first order Stokes signal from the first laser pump signal in an optical resonator; measuring a first beat signal frequency; ceasing transmission of the first laser pump signal to the optical resonator; transmitting a second laser pump signal to the optical resonator; adjusting a frequency of the second laser pump signal; generating a first order Stokes signal from the second laser pump signal in the optical resonator; and measuring a second beat signal frequency; ceasing transmission of the second laser pump signal to the optical resonator.Type: GrantFiled: June 1, 2017Date of Patent: May 14, 2019Assignee: Honeywell International Inc.Inventors: Tiequn Qiu, Jianfeng Wu, Matthew Wade Puckett
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Patent number: 10281646Abstract: An acousto-optic waveguide device comprises a substrate comprising a first material having a first refractive index and a first acoustic velocity; a cladding layer over the substrate, the cladding layer comprising a second material having a second refractive index that is distinct from the first refractive index, the second material having a second acoustic velocity that is distinct from the first acoustic velocity; and an optical core surrounded by the cladding layer, the optical core comprising a third material having a third refractive index that is higher that the first refractive index and the second refractive index, the third material having a third acoustic velocity that is distinct from the first acoustic velocity and the second acoustic velocity. The cladding layer that surrounds the optical core has a thickness configured to substantially confine acoustic waves to the cladding layer when an optical signal propagates through the optical core.Type: GrantFiled: May 10, 2017Date of Patent: May 7, 2019Assignee: Honeywell International Inc.Inventors: Matthew Wade Puckett, Jianfeng Wu, Mary Salit, Tiequn Qiu
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Publication number: 20190041215Abstract: Systems and methods for reducing polarization-related bias errors in RFOGS are described herein. In certain implementations, an RFOG system includes a fiber optic resonator, one or more laser sources, wherein light from the laser sources launches first and second optical beams into the fiber optic resonator in opposite directions, and an electro-optically tunable devices in the resonator path configured to modulate the phase difference between polarization components in the first and second optical beams as the optical beams propagate within the fiber optic resonator. The system further includes at least one photodetector, wherein the polarization components of the first and second optical beams are incident on the photodetector, wherein the at least one photodetector provides an electrical signal, and at least one processing unit configured to receive the electrical signal and calculate a rotation rate for the RFOG and provide a drive signal for the electro-optically tunable device.Type: ApplicationFiled: August 3, 2017Publication date: February 7, 2019Inventors: Glen A. Sanders, Marc Smiciklas, Tiequn Qiu, Jianfeng Wu, Lee K. Strandjord