Patents by Inventor Kerry Vahala

Kerry Vahala 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: 10886691
    Abstract: A ring optical resonator is formed on a substrate. An outer circumferential surface of the resonator substantially confines one or more circumferential resonant optical modes. The resonator is positioned above a void formed in the substrate and is supported above the void by a portion of a material layer on the substrate that extends radially inward above the void from an outer circumferential edge of the void to the outer circumferential surface of the resonator. An optical waveguide can be integrally formed on the substrate and traverses a portion of the material layer above the void. The optical waveguide and the ring optical resonator are arranged and positioned so as to establish evanescent optical coupling between them. Q-factors of 108 or more have been achieved with a silica resonator and silicon nitride waveguide integrally formed on a silicon substrate.
    Type: Grant
    Filed: May 5, 2017
    Date of Patent: January 5, 2021
    Assignee: CALIFORNIA INSTITUTE OF TECHNOLOGY
    Inventors: Kerry Vahala, Kiyoul Yang, Dong Yoon Oh, Seung Hoon Lee
  • Patent number: 10523214
    Abstract: A voltage-controlled oscillator generates a VCO output signal at frequency fM. A dual optical-frequency source generates optical signals at frequencies v1S and v2S. An electro-optic frequency divider (EOFD) generates multiple optical sidebands spaced by fM, and from two sidebands generates a beat signal at beat frequency ?f. A first control circuit generates an error signal from the beat signal and a first reference signal at frequency fREF1, and couples the VCO and the EOFD in a negative feedback arrangement that stabilizes the output frequency fM. A second control circuit generates an error signal from the frequency-divided output signal and a second reference signal at frequency fREF2, and couples the VCO and one or both of the dual source or the first reference signal in a negative feedback arrangement that stabilizes, or compensates for fluctuations of, a difference frequency v2S?v1S.
    Type: Grant
    Filed: April 28, 2018
    Date of Patent: December 31, 2019
    Assignee: HQPHOTONICS INC.
    Inventors: Jiang Li, Kerry Vahala
  • Patent number: 10074959
    Abstract: A modulated semiconductor laser source includes a waveguide on a semiconductor substrate; first and second reflectors; a laser electrode; an optical modulator; and a laser-electrode electrical circuit. The reflectors and a resonator segment of the waveguide define a laser resonator with laser output transmitted through the second reflector. The laser electrode is positioned over the resonator segment and a laser current flows through the laser electrode into the resonator segment to produce optical gain. The modulator receives and modulates the laser output, in response to a primary modulation signal, to produce a modulated output optical signal. The laser-electrode circuit is coupled to the laser electrode and derives from the primary modulation signal a laser-electrode secondary modulation current, optimized to reduce chirp in the modulated output signal, that flows through the laser electrode into or out of the resonator segment in addition to the laser current.
    Type: Grant
    Filed: August 3, 2016
    Date of Patent: September 11, 2018
    Assignee: EMCORE CORPORATION
    Inventors: Henry A. Blauvelt, Xiaoguang He, Kerry Vahala
  • Patent number: 10067031
    Abstract: A dual-comb optical-frequency comb generator includes a tunable comb-generating laser, a coarse-comb generator, a fine-comb generator, a second harmonic generator, a coarse-comb offset photodetector, a dual-comb offset photodetector, and a fine-comb photodetector. The coarse comb is self-referencing and coupled to the fine comb so as to enable absolute determination of the frequencies of the fine comb.
    Type: Grant
    Filed: May 8, 2017
    Date of Patent: September 4, 2018
    Assignees: CALIFORNIA INSTITUTE OF TECHNOLOGY, THE REGENTS OF THE UNIVERSITY OF CALIFORNIA, THE UNITED STATES OF AMERICA
    Inventors: Kerry Vahala, John E. Bowers, Kartik A. Srinivasan, Scott B. Papp, Scott A. Diddams
  • Patent number: 10014649
    Abstract: A stabilized laser source includes a fiber-ring Brillouin laser that incorporates a circulator for non-reciprocal operation and for launching of a pump optical signal. Most of the pump optical signal is launched in a forward direction and drives Brillouin laser oscillation in the backward direction, a portion of which exits via an optical coupler as the optical output of the laser source. A small fraction of the pump optical signal is launched in the backward direction via the optical coupler, and a fraction of that backward-propagating pump optical signal exits via the optical coupler as an optical feedback signal. A frequency-locking mechanism receives the optical feedback signal and controls the pump optical frequency to maintain resonant propagation of the backward-propagating pump optical signal. A second pump optical signal can be launched in the forward direction to generate a second Brillouin laser oscillation.
    Type: Grant
    Filed: December 21, 2016
    Date of Patent: July 3, 2018
    Assignees: CALIFORNIA INSTITUTE OF TECHNOLOGY, HQPHOTONICS INC.
    Inventors: Jiang Li, Kerry Vahala
  • Patent number: 10009103
    Abstract: A microwave-frequency source at frequency fM comprises: a dual optical-frequency reference source, an electro-optic sideband generator, an optical bandpass filter, an optical detector, a reference oscillator, an electrical circuit, and a voltage-controlled oscillator (VCO). The sideband generator modulates dual optical reference signals at v2 and v1 to generate sideband signals at v1±n1fM and v2±n2fM. The bandpass filter transmits sideband signals at v1+N1fM and v2?N2fM. The optical detector generates a beat note at (v2?N2fM)?(v1+N1fM). The beat note and a reference oscillator signal are processed by the circuit to generate a loop-filtered error signal to input to the VCO. Output of the VCO at fM drives the sideband generator and forms the microwave-frequency output signal. The resultant frequency division results in reduced phase noise on the microwave-frequency signal.
    Type: Grant
    Filed: August 11, 2016
    Date of Patent: June 26, 2018
    Assignees: CALIFORNIA INSTITUTE OF TECHNOLOGY, THE UNITED STATES OF AMERICA, AS REPRESENTED BY THE SECRETARY OF COMMERCE
    Inventors: Kerry Vahala, Scott Diddams, Jiang Li, Xu Yi, Hansuek Lee
  • Publication number: 20180095003
    Abstract: A dual-comb optical-frequency comb generator includes a tunable comb-generating laser, a coarse-comb generator, a fine-comb generator, a second harmonic generator, a coarse-comb offset photodetector, a dual-comb offset photodetector, and a fine-comb photodetector. The coarse comb is self-referencing and coupled to the fine comb so as to enable absolute determination of the frequencies of the fine comb.
    Type: Application
    Filed: May 8, 2017
    Publication date: April 5, 2018
    Inventors: Kerry Vahala, John E. Bowers, Kartik A. Srinivasan, Scott B. Papp, Scott A. Diddams
  • Patent number: 9905999
    Abstract: Microwave-frequency signal generation by generating multiple sideband optical signals separated by phase-modulation frequency fM, generating beat signals between one or two sidebands and one or two optical reference signals, generating a loop-filtered error signal by comparing an electrical reference signal to one of the beat signals or their difference, and controlling with the error signal in a phase-locked loop arrangement a voltage-controlled oscillator (VCO) that drives the sideband generation at the frequency fM. A portion of the VCO output is the generated microwave-frequency signal.
    Type: Grant
    Filed: February 25, 2016
    Date of Patent: February 27, 2018
    Assignee: CALIFORNIA INSTITUTE OF TECHNOLOGY
    Inventors: Jiang Li, Kerry Vahala
  • Publication number: 20180041006
    Abstract: A modulated semiconductor laser source includes a waveguide on a semiconductor substrate; first and second reflectors; a laser electrode; an optical modulator; and a laser-electrode electrical circuit. The reflectors and a resonator segment of the waveguide define a laser resonator with laser output transmitted through the second reflector. The laser electrode is positioned over the resonator segment and a laser current flows through the laser electrode into the resonator segment to produce optical gain. The modulator receives and modulates the laser output, in response to a primary modulation signal, to produce a modulated output optical signal. The laser-electrode circuit is coupled to the laser electrode and derives from the primary modulation signal a laser-electrode secondary modulation current, optimized to reduce chirp in the modulated output signal, that flows through the laser electrode into or out of the resonator segment in addition to the laser current.
    Type: Application
    Filed: August 3, 2016
    Publication date: February 8, 2018
    Inventors: Henry A. Blauvelt, Xiaoguang He, Kerry Vahala
  • Publication number: 20180006424
    Abstract: A ring optical resonator is formed on a substrate. An outer circumferential surface of the resonator substantially confines one or more circumferential resonant optical modes. The resonator is positioned above a void formed in the substrate and is supported above the void by a portion of a material layer on the substrate that extends radially inward above the void from an outer circumferential edge of the void to the outer circumferential surface of the resonator. An optical waveguide can be integrally formed on the substrate and traverses a portion of the material layer above the void. The optical waveguide and the ring optical resonator are arranged and positioned so as to establish evanescent optical coupling between them. Q-factors of 108 or more have been achieved with a silica resonator and silicon nitride waveguide integrally formed on a silicon substrate.
    Type: Application
    Filed: May 5, 2017
    Publication date: January 4, 2018
    Inventors: Kerry Vahala, Kiyoul Yang, Dong Yoon Oh, Seung Hoon Lee
  • Publication number: 20170302048
    Abstract: A stabilized laser source includes a fiber-ring Brillouin laser that incorporates a circulator for non-reciprocal operation and for launching of a pump optical signal. Most of the pump optical signal is launched in a forward direction and drives Brillouin laser oscillation in the backward direction, a portion of which exits via an optical coupler as the optical output of the laser source. A small fraction of the pump optical signal is launched in the backward direction via the optical coupler, and a fraction of that backward-propagating pump optical signal exits via the optical coupler as an optical feedback signal. A frequency-locking mechanism receives the optical feedback signal and controls the pump optical frequency to maintain resonant propagation of the backward-propagating pump optical signal. A second pump optical signal can be launched in the forward direction to generate a second Brillouin laser oscillation.
    Type: Application
    Filed: December 21, 2016
    Publication date: October 19, 2017
    Inventors: Jiang LI, Kerry VAHALA
  • Patent number: 9595918
    Abstract: A microwave-frequency source, generating an output electrical signal at an output frequency fM, comprises a pump laser source, an optical resonator, and a photodetector. Free spectral range vFSR of the optical resonator equals an integer submultiple of a Brillouin shift frequency vB of the optical resonator (i.e., vB=MvFSR). The pump laser source is frequency-locked to a corresponding resonant optical mode of the optical resonator. Pumping the optical resonator with output of the pump laser source at a pump frequency vpump results in stimulated Brillouin laser oscillation in the optical resonator at respective first, second, and third Stokes Brillouin-shifted frequencies v1=vpump?vB, v2=vpump?2vB, and v3=vpump?3vB. The photodetector receives stimulated Brillouin laser outputs at the first and third Stokes Brillouin-shifted frequencies v1 and v3 and generates therefrom the output electrical signal at a beat frequency fM=v1?v3=2vB.
    Type: Grant
    Filed: March 6, 2015
    Date of Patent: March 14, 2017
    Assignee: California Institute of Technology
    Inventors: Jiang Li, Kerry Vahala
  • Patent number: 9564733
    Abstract: A semiconductor device comprising a substrate; a monolithic gain region disposed on the substrate and operable to produce optical gain in response to current injection, including a first electrode over a first portion of the gain region having a first length L1, with a first current I1 being applied; and a second electrode over a second portion of the gain region having a second length L2, with a second current I2 being applied; wherein I1/L1 is greater than I2/L2.
    Type: Grant
    Filed: April 4, 2016
    Date of Patent: February 7, 2017
    Assignee: EMCORE CORPORATION
    Inventors: Henry A. Blauvelt, Xiaoguang He, Kerry Vahala
  • Patent number: 9564734
    Abstract: A method of making an optical modulator by determining the material composition of the quantum well region in the waveguide portion of the modulator so that the modulator is transparent at a gain peak wavelength that is greater than the predetermined wavelength by a predetermined amount, and fabricating the modulator with the determined material composition.
    Type: Grant
    Filed: March 25, 2016
    Date of Patent: February 7, 2017
    Assignee: EMCORE CORPORATION
    Inventors: Henry A. Blauvelt, Xiaoguang He, Kerry Vahala
  • Publication number: 20170012705
    Abstract: A microwave-frequency source at frequency fM comprises: a dual optical-frequency reference source, an electro-optic sideband generator, an optical bandpass filter, an optical detector, a reference oscillator, an electrical circuit, and a voltage-controlled oscillator (VCO). The sideband generator modulates dual optical reference signals at v2 and v1 to generate sideband signals at v1±n1fM and v2±n2fM. The bandpass filter transmits sideband signals at v1+N1fM and v2?N2fM. The optical detector generates a beat note at (v2?N2fM)?(v1+N1fM). The beat note and a reference oscillator signal are processed by the circuit to generate a loop-filtered error signal to input to the VCO. Output of the VCO at fM drives the sideband generator and forms the microwave-frequency output signal. The resultant frequency division results in reduced phase noise on the microwave-frequency signal.
    Type: Application
    Filed: August 11, 2016
    Publication date: January 12, 2017
    Inventors: Kerry VAHALA, Scott DIDDAMS, Jiang LI, Xu YI, Hansuek LEE
  • Patent number: 9537571
    Abstract: A dual-frequency optical source comprises: (a) first and second pump laser sources arranged to generate optical pump power at respective first and second pump laser frequencies vpump1 and vpump2; and (b) a fiber optical resonator characterized by a Brillouin shift frequency vB and a free spectral range that is substantially equal to an integer submultiple of the Brillouin shift frequency. Each one of the first and second pump laser sources is frequency-locked to a corresponding resonant optical mode of the fiber optical resonator. First and second optical output signals of the dual-frequency optical reference source at respective first and second output frequencies v1=vpump1?vB and v2=vpump2?vB comprise stimulated Brillouin laser output generated by simultaneous optical pumping of the fiber optical resonator by the first and second pump laser sources, respectively. An output difference frequency v2?v1 is greater than about 300 GHz.
    Type: Grant
    Filed: January 26, 2015
    Date of Patent: January 3, 2017
    Assignee: CALIFORNIA INSTITUTE OF TECHNOLOGY
    Inventors: Jiang Li, Kerry Vahala
  • Patent number: 9450673
    Abstract: A microwave-frequency source at frequency fM comprises: a dual optical-frequency reference source, an electro-optic sideband generator, an optical bandpass filter, an optical detector, a reference oscillator, an electrical circuit, and a voltage-controlled oscillator (VCO). The sideband generator modulates dual optical reference signals at v2 and v1 to generate sideband signals at v1±n1fM and v2±n2fM. The bandpass filter transmits sideband signals at v1+N1fM and v2?N2fM. The optical detector generates a beat note at (v2?N2fM)?(v1+N1fM). The beat note and a reference oscillator signal are processed by the circuit to generate a loop-filtered error signal to input to the VCO. Output of the VCO at fM drives the sideband generator and forms the microwave-frequency output signal. The resultant frequency division results in reduced phase noise on the microwave-frequency signal.
    Type: Grant
    Filed: January 26, 2015
    Date of Patent: September 20, 2016
    Assignees: CALIFORNIA INSTITUTE OF TECHNOLOGY, THE UNITED STATES OF AMERICA, AS REPRESENTED BY THE SECRETARY OF COMMERCE, THE NATIONAL INSTITUTE OF STANDARDS AND TECHNOLOGY
    Inventors: Kerry Vahala, Scott Diddams, Jiang Li, Xu Yi, Hansuek Lee
  • Patent number: 9438007
    Abstract: An optical modulator including an information-containing radio frequency signal input; a semiconductor device having an optical input optically for receiving the coherent light beam, and a electrode connected to said radio frequency signal input and having a modulated bias potential so that current is generated in the second semiconductor device and extracted therefrom, while the coherent light beam is optically modulated by the signal changing the carrier density in the semiconductor device.
    Type: Grant
    Filed: June 15, 2015
    Date of Patent: September 6, 2016
    Assignee: EMCORE CORPORATION
    Inventors: Henry A. Blauvelt, Xiaoguang He, Kerry Vahala
  • Publication number: 20160254646
    Abstract: Microwave-frequency signal generation by generating multiple sideband optical signals separated by phase-modulation frequency fM, generating beat signals between one or two sidebands and one or two optical reference signals, generating a loop-filtered error signal by comparing an electrical reference signal to one of the beat signals or their difference, and controlling with the error signal in a phase-locked loop arrangement a voltage-controlled oscillator (VCO) that drives the sideband generation at the frequency fM. A portion of the VCO output is the generated microwave-frequency signal.
    Type: Application
    Filed: February 25, 2016
    Publication date: September 1, 2016
    Inventors: Jiang LI, Kerry VAHALA
  • Publication number: 20160248223
    Abstract: A semiconductor device comprising a substrate; a monolithic gain region disposed on the substrate and operable to produce optical gain in response to current injection, including a first electrode over a first portion of the gain region having a first length L1, with a first current I1 being applied; and a second electrode over a second portion of the gain region having a second length L2, with a second current I2 being applied; wherein I1/L1 is greater than I2/L2.
    Type: Application
    Filed: April 4, 2016
    Publication date: August 25, 2016
    Inventors: Henry A. Blauvelt, Xiaoguang He, Kerry Vahala