Abstract: A resonator fiber optic gyroscope comprises a master laser that emits a reference optical signal, a first slave laser that emits a first optical signal and is responsive to the reference optical signal through a first optical phase lock loop (OPLL), and a second slave laser that emits a second optical signal and is responsive to the reference optical signal through a second OPLL. A reference resonator in optical communication with the master laser receives the reference optical signal, and comprises a first fiber optic coil having a first cavity length. A gyro resonator, in optical communication with the first and second slave lasers, receives the first and second optical signals. The gyro resonator comprises a second fiber optic coil having a second cavity length longer than the first cavity length. The reference resonator has an operating frequency that substantially tracks with an operating frequency of the gyro resonator.

Abstract: Systems and methods for an intensity stabilized resonator fiber optic gyroscope are provided. In one embodiment, a method for providing optical intensity stabilization system for a resonator fiber optic gyroscope (RFOG) is provided. The method comprises: injecting a phase modulated light beam into a fiber optic ring resonator coil; measuring a DC component of the phase modulated light beam at an output of the fiber optic ring resonator coil; generating a feedback control signal based on the DC component; and attenuating the phase modulated light beam prior to injection into the fiber optic ring resonator coil by controlling a variable optical attenuator with the feedback control signal.

Abstract: A method of measuring beat frequency comprises modulating a first optical signal and a second optical signal, wherein the first modulated optical signal includes a first carrier frequency and a first plurality of sideband frequencies and the second modulated optical signal includes a second carrier frequency and a second plurality of sideband frequencies. The method also comprises combining a fraction of the first modulated optical signal with a fraction of the second modulated optical signal into a combined signal and determining a carrier beat frequency. The method further comprises selecting a frequency range from the combined signal; performing a fast Fourier transform (FFT) on an electrical signal representing the selected frequency range; tracking the carrier beat frequency based on the FFT; and outputting a rate signal based on the tracked carrier beat frequency, the rate signal indicating a rotation rate of the resonator fiber optic gyroscope.

Abstract: Systems and methods for a resonant fiber optic gyroscope with a polarizing crystal waveguide coupler are provided. In one embodiment, an optical fiber resonator comprises: a polarizing single crystal material having a first crystal lattice axis; a first waveguide formed in the crystal material; a second waveguide formed in the crystal material running parallel to the first waveguide; and an optical fiber sensing coil. The first waveguide comprises a bend that approaches the second waveguide defining a coupling region between the first and second waveguides. The first and second waveguides are polarized to guide light having a polarization state aligned to the first crystal lattice axis. The second waveguide and the sensing coil are coupled into a resonator configuration forming a ring resonator, the second waveguide comprising a first port coupled to a first end of the coil, and a second port coupled to a second end of the coil.

Abstract: Systems and methods for a small low cost resonator fiber optic gyroscope (RFOG) with reduced optical errors are provided. In one embodiment, a RFOG comprises: a light source; an optical chip configured to couple a clockwise optical signal and a counterclockwise optical signal from the light source into a fiber optic resonator and couple the clockwise optical signal and the counterclockwise optical signal from the fiber optic resonator to at least one photodetector. The fiber optic resonator comprises a fiber optic coil having a first end point and a second end point. The fiber optic coil has a 90-degree splice located substantially half-way between the first end point and the second end point, is wrapped around a first fiber stretcher located between the first end point and the 90-degree splice, and is wrapped around a second fiber stretcher that is located between the second end point and the 90-degree splice.

Abstract: A resonator fiber optic gyroscope comprises a master laser that emits a reference optical signal, a first slave laser that emits a clockwise optical signal, and a second slave laser that emits a counter-clockwise optical signal. A resonator ring cavity in optical communication with the first slave laser and second slave laser is configured to receive the optical signals from the slave lasers without receiving the reference optical signal. A reflected optical signal from the cavity is directed to a feedback laser stabilization loop for the master laser that includes a common modulation frequency scheme. A frequency of the optical signal from the master laser is indirectly locked onto a resonance frequency of the cavity with a fixed frequency offset, which is determined by a relative frequency between the optical signal of the first slave laser or the second slave laser, and the optical signal of the master laser.

Abstract: One embodiment is directed to a resonator fiber optic gyroscope (RFOG). The optical fiber resonator includes an optical fiber, one or more optical filters that suppresses the noise light in the resonator, one or more variable optical attenuators (VOAs) that can adjust the loss of the resonator with fast response, and one or more optical gain elements that provide amplification of light to offset part of the losses of the resonator. The RFOG also includes one or more pump lasers to produce one or more pump beams for the gain elements in the resonator and control electronics configured to control the one or more pump lasers and the one or more variable optical attenuators, such that the round-trip loss of the resonator is a substantially constant, positive value.

Abstract: Systems and methods for stabilized stimulated Brillouin scattering lasers with ultra-low phase noise are provided. In one embodiment, a method for producing a Stimulated Brillouin Scattering (SBS) beam comprises: generating laser light from a tunable laser source; splitting the laser light into a first light beam and a second light beam; creating a phase modulated light beam by applying a phase modulation to the first light beam; locking a frequency of the laser light to a frequency of a ring cavity using the phase modulated light beam and a Pound-Drever-Hall servo loop coupled to the tunable laser source; coupling the second light beam into the ring cavity in a direction of travel opposite to that of the phase modulated light beam; generating a Stimulated Brillouin Scattering light beam in the ring cavity from the second light beam; and outputting the Stimulated Brillouin Scattering light beam.

Abstract: Systems and methods for an intensity stabilized resonator fiber optic gyroscope are provided. In one embodiment, a method for providing optical intensity stabilization system for a resonator fiber optic gyroscope (RFOG) is provided. The method comprises: injecting a phase modulated light beam into a fiber optic ring resonator coil; measuring a DC component of the phase modulated light beam at an output of the fiber optic ring resonator coil; generating a feedback control signal based on the DC component; and attenuating the phase modulated light beam prior to injection into the fiber optic ring resonator coil by controlling a variable optical attenuator with the feedback control signal.

Abstract: A light-source system to output at least one stable phase modulated coherent light beam is provided. The light-source system includes a multi-frequency laser system, at least one phase modulator, at least one feedback photodetector, and at least one modulation servo. The multi-frequency laser system emits a reference light beam and provides at least one unmodulated-light beam having a respective at least one carrier frequency offset from the reference carrier frequency. The phase modulator modulates the unmodulated-light beam provided by the multi-frequency laser system. The frequency-selection device monitors a frequency component of interest. The feedback photodetector provides information indicative of beat frequencies between the reference light beam and the modulated-light beam.

Abstract: Systems and methods for stabilized stimulated Brillouin scattering lasers with ultra-low phase noise are provided. In one embodiment, a method for producing a Stimulated Brillouin Scattering (SBS) beam comprises: generating laser light from a tunable laser source; splitting the laser light into a first light beam and a second light beam; creating a phase modulated light beam by applying a phase modulation to the first light beam; locking a frequency of the laser light to a frequency of a ring cavity using the phase modulated light beam and a Pound-Drever-Hall servo loop coupled to the tunable laser source; coupling the second light beam into the ring cavity in a direction of travel opposite to that of the phase modulated light beam; generating a Stimulated Brillouin Scattering light beam in the ring cavity from the second light beam; and outputting the Stimulated Brillouin Scattering light beam.

Abstract: A multi-core transport system for a resonant fiber optic gyroscope is provided. The transport system has a transport fiber configured to transmit a clockwise signal and a counterclockwise signal, wherein the transport fiber has at least a first core and a second core. The first core and second core are configured such that when the first core imparts a first effect on the clockwise signal, the second core imparts a second effect on the counterclockwise signal, wherein the second effect substantially mirrors the first effect. The system further comprises a first coupler configured to optically couple the clockwise signal to the first core, and the counterclockwise signal to the second core; and a second coupler configured to optically couple the clockwise signal from the first core to a resonator, and the counterclockwise signal from the second core to the resonator.

Abstract: One embodiment is directed to a resonator fiber optic gyroscope (RFOG). The optical fiber resonator includes an optical fiber, one or more optical filters that suppresses the noise light in the resonator, one or more variable optical attenuators (VOAs) that can adjust the loss of the resonator with fast response, and one or more optical gain elements that provide amplification of light to offset part of the losses of the resonator. The RFOG also includes one or more pump lasers to produce one or more pump beams for the gain elements in the resonator and control electronics configured to control the one or more pump lasers and the one or more variable optical attenuators, such that the round-trip loss of the resonator is a substantially constant, positive value.

Abstract: A resonator fiber optic gyroscope (RFOG) is provided. The RFOG includes a fiber coil, first and second lasers, first and second phase modulators, and a common phase modulator. The first laser generates CW input light for propagation in the CW direction of the fiber coil. The second laser generates CCW input light for propagation in the CCW direction of the fiber coil. The first phase modulator modulates the CW input light with modulation frequency f1=(n+0.5)*FSR. The second phase modulator modulates the CCW input light with modulation frequency f2=(m+0.5)*FSR so that overlap of major sidebands is avoided. The phase modulation amplitudes of the first and second modulators substantially suppress the optical carrier components of the CW and CCW input light. The common phase modulator is configured to modulate the CW and CCW input light with a common phase modulation frequency and a common phase amplitude.

Abstract: A method of measuring beat frequency comprises modulating a first optical signal and a second optical signal, wherein the first modulated optical signal includes a first carrier frequency and a first plurality of sideband frequencies and the second modulated optical signal includes a second carrier frequency and a second plurality of sideband frequencies. The method also comprises combining a fraction of the first modulated optical signal with a fraction of the second modulated optical signal into a combined signal and determining a carrier beat frequency. The method further comprises selecting a frequency range from the combined signal; performing a fast Fourier transform (FFT) on an electrical signal representing the selected frequency range; tracking the carrier beat frequency based on the FFT; and outputting a rate signal based on the tracked carrier beat frequency, the rate signal indicating a rotation rate of the resonator fiber optic gyroscope.

Abstract: Systems and methods for a polarization matched resonator fiber optic gyroscope are provided. In one embodiment an RFOG comprises: a light source; a fiber optic ring resonator; a photodetector that outputs an electrical signal that varies as a function of optical intensity; and an input light polarization servo. A light beam from the servo is launched into the resonator ring in a first direction of circulation. The input polarization servo comprises a birefringence modulator that modulates a phase shift between two components of an input polarization state of the light beam at ?m, the modulator is controlled to drive towards zero a 1st harmonic of ?m as measured in the electrical signal. The servo further comprises a tunable ½ waveplate that adjusts an amplitude of the two components of the input polarization state relative to each other. The tunable ½ waveplate is controlled to maximize a peak optical intensity as measured in the electrical signal.

Abstract: A dispersion managed interferometric fiber optic gyroscope comprising: a coupler coupled to the broadband light source via a first input fiber; an IOC comprising: a beamsplitter that directs the input signal to a first output and a second output; a combiner configured to combine a first return signal from the first output and a second return signal from the second output into a combined return signal; an integrated optical circuit input coupled to the coupler via a second input fiber; a fiber optic gyroscope sensing coil coupled to a first pigtail fiber and second pigtail fiber, the sensing coil comprising sensing fibers, wherein at least one dispersion slope of at least one of the first input fiber, second input fiber, first pigtail fiber, second pigtail fiber, and the sensing fibers is selected such that the signals at the IOC input has a second order coherence substantially equal to two.

Abstract: A dispersion managed interferometric fiber optic gyroscope comprising: a coupler coupled to the broadband light source via a first input fiber; an IOC comprising: a beamsplitter that directs the input signal to a first output and a second output; a combiner configured to combine a first return signal from the first output and a second return signal from the second output into a combined return signal; an integrated optical circuit input coupled to the coupler via a second input fiber; a fiber optic gyroscope sensing coil coupled to a first pigtail fiber and second pigtail fiber, the sensing coil comprising sensing fibers, wherein at least one dispersion slope of at least one of the first input fiber, second input fiber, first pigtail fiber, second pigtail fiber, and the sensing fibers is selected such that the signals at the IOC input has a second order coherence substantially equal to two.

Abstract: A resonator fiber optic gyroscope is provided. The resonator fiber optic gyroscope includes a gyroscope resonator, a laser; a clockwise modulator; a clockwise circulator; a clockwise reflection detector; a first-lock-in-amplifier, a clockwise-resonance-tracking servo to receive output from the first-lock-in-amplifier and to provide feedback to the laser to lock the laser to the gyroscope resonator; a clockwise transmission detector to detect an optical beam output from the counter-clockwise input port; a second servo; a second-lock-in-amplifier; and a third-lock-in-amplifier. The first and second lock-in-amplifiers demodulate at the first harmonic of the modulation frequency. The second-lock-in-amplifier demodulates at the second harmonic of the modulation frequency. Either the modulation frequency of the clockwise optical beam is locked to (n+0.5) times the FSR through the second servo, where n is zero or a positive integer, or the FSR is locked to 1/(n+0.

Abstract: A resonator fiber optic gyroscope is provided. The resonator fiber optic gyroscope includes a gyroscope resonator, a laser; a clockwise modulator; a clockwise circulator; a clockwise reflection detector; a first-lock-in-amplifier, a clockwise-resonance-tracking servo to receive output from the first-lock-in-amplifier and to provide feedback to the laser to lock the laser to the gyroscope resonator; a clockwise transmission detector to detect an optical beam output from the counter-clockwise input port; a second servo; a second-lock-in-amplifier; and a third-lock-in-amplifier. The first and second lock-in-amplifiers demodulate at the first harmonic of the modulation frequency. The second-lock-in-amplifier demodulates at the second harmonic of the modulation frequency. Either the modulation frequency of the clockwise optical beam is locked to (n+0.5) times the FSR through the second servo, where n is zero or a positive integer, or the FSR is locked to 1/(n+0.