Honeywell International Inc.

Honeywell International Inc. Intellectual Property - Patent Services

Tiequn Qiu

Glen Aaron Sanders

Lee Kevin Strandjord

Jianfeng Wu

Matthew Wade Puckett

Steven Tin

Mary Salit

Steven J Sanders

Marc Smiciklas

John R Feth

Sorin Mosor

Neil A Krueger

Teresa M Marta

Jennifer S Strabley

Norman Gerard Tarleton

Clarence E Laskoskie

Andrew W Kaliszek

Waymon Ho

Sorin Moser

Barbara Vizenor

Mary K Salit

John Feth

Lee K Srandjord

Clarence Eugene Laskoskie

Various examples of a closed-loop optical gyroscope are disclosed. The closed-loop optical gyroscope includes a broadband light source configured to generate broadband optical signal(s). The broadband optical signal(s) propagate in an optical resonator and are coupled in and out of the optical resonator by optical couplers. A phase modulator applies phase modulation to the optical signal(s) based on a sawtooth modulation signal. The optical signal(s) repropagate in the optical resonator in a different direction. The optical signal(s) are then received and analyzed to determine parameter(s) of the phase modulator. One or more processors configure the phase modulator based on the determined parameter(s).

Closed loop operation of broadband resonator optical gyroscope using sawtooth phase modulations

A method of operating a resonator optical gyroscope includes generating optical signals having a broadband frequency range. The method includes coupling the optical signals into an optical resonator (OR) to propagate in a first direction and coupling the optical signals out of the OR after the optical signals pass through the OR in the first direction. The method includes coupling optical signals into the OR to propagate in a second direction and coupling optical signals out of the OR after the optical signals pass through the OR in the second direction. The method includes amplifying the optical signals coupled out of the OR by the second optical coupler or the optical signals coupled out of the OR by the first optical coupler to generate amplified optical signals and generating electrical signals corresponding to the amplified optical signals. The method includes determining a rotation rate based on the electrical signals.

Broadband resonator optical gyroscope with efficient optical power management for low shot noise

A gyroscope comprises first and second light sources that emit first and second beams with broadband spectrums, and a waveguide arrangement that communicates with the light sources. A resonator communicates with the waveguide arrangement to receive the beams. A first circulator is coupled to the waveguide arrangement between the first light source and the resonator. A second circulator is coupled to the waveguide arrangement between the second light source and the resonator. A first rate detector communicates with the resonator through the first circulator, and a second rate detector communicates with the resonator through the second circulator. The rate detectors produce rate measurements based on a detected resonance frequency shift of the beams in the resonator caused by rotation of the gyroscope. Outputs of the rate detectors are used to calculate a rotation rate that is corrected for errors due to a time varying pathlength change in the resonator.

Resonator optical gyroscopes with dual broadband light sources

A method of operating a resonator optical gyroscope includes generating optical signals having broadband frequency range; coupling optical signals into optical resonator (OR) to propagate in first direction and out of OR after optical signals pass through OR in first direction; applying phase modulation to optical signals coupled out of OR to generate phase-modulated optical signals; filtering first portion of phase-modulated optical signals to generate filtered, phase-modulated optical signals; generating first electrical signals indicative of power level of the filtered, phase-modulated optical signals and RIN; coupling second portion of phase-modulated optical signals into OR to propagate in second direction and out of OR after phase-modulated optical signals pass through the OR in second direction; generating second electrical signals indicative of power level of phase-modulated optical signals after passing through OR in second direction; and determining a rotation rate based on the first electrical signals and the second electrical signals.

Systems and methods for effective relative intensity noise subtraction for a broadband resonator optical gyroscope

A photonics gyroscope comprises a light source on a photonics chip that emits a broadband beam; a waveguide resonator; a reflective component; first and second detectors, the second detector coupled to the source; a RIN servo loop coupled between the second detector and the source; and a rate calculation unit. The beam is directed into the resonator such that it propagates in a CCW direction. A portion of the CCW beam is coupled out of the resonator toward the reflective component and reflected back as a reflected beam that is coupled into the resonator such that the reflected beam propagates in a CW direction. The CW beam is coupled out of the resonator to the first detector, which detects a resonance frequency shift between the CW and CCW beams. The RIN servo loop stabilizes an intensity of the beam such that bias error and noise is reduced.

Photonics gyroscope with broadband light source

Techniques are provided for diminishing bias error, in a resonator optical gyroscope, due to an undesired, parasitic optical mode which is orthogonal to a desired optical mode. Energy levels of the undesired, parasitic mode can be diminished utilizing polarizing beam splitters each of which suppresses energy of the undesired, parasitic mode of a clockwise or a counterclockwise optical signal more than energy of the desired mode of the CW optical signal. Optionally, one or more components of a travelling wave resonator system are configured to suppress energy of the undesired, parasitic mode of a clockwise and/or a counterclockwise optical signal more than energy of the desired mode of the respective optical signal(s). Optionally, the desired optical mode is either a transverse magnetic (TM) mode or a transverse electric (TE) mode, and the undesired, parasitic optical mode is respectively the TE mode or the TM mode.

Resonator optical gyroscope with diminished bias error

Techniques are provided for implementing and using a high quality factor travelling wave resonator configured to propagate a transverse magnetic mode optical signals and suppress transverse electric mode optical signals. The travelling wave resonator may be used in a resonator optical gyroscope.

Transverse magnetic mode travelling wave resonator with at least one Bragg grating and gyroscope applications thereof

Techniques are provided for implementing and using a travelling wave resonator, comprising planar optical waveguide including at least two stacked cores, to diminish Kerr effect in the travelling wave resonator. The travelling wave resonator may be used in a resonator optical gyroscope.

Resonator with at least two cores and gyroscope applications thereof

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.

Reducing rotation sensing errors from laser source signal and modulation cross-talk

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.

Apparatus and methods for stable bidirectional output from ring laser gyroscope

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.

Sideband heterodyne switching for resonator fiber optic gyroscopes (RFOGs)

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.

Systems and methods for correcting errors in gyroscopes

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.

Etchless acoustic waveguiding in integrated acousto-optic waveguides

In one embodiment, a method of operating a glare reduction and ranging optical system having an image sensor with pixels is provided. The method comprises: generating a first light beam with a power spectral density; generating a reference light beam from the first light beam; emitting the first light beam with a power spectral density; collecting scattered light and reflected light respectively reflected from a scattering medium and a target; determining a power spectral density of the first light beam so that the first light beam is substantially coherent with the scattered light; adjusting the power spectral density of the first light beam so that the reference light beam is substantially coherent with the scattered light; on a pixel by pixel basis, modifying the amplitude and phase of the reference light beam to minimize the DC light power at each pixel; storing the modified amplitude and phase that results in a substantially minimum detected DC light power for each pixel; increasing power spectral density of a second reference light beam; modulating the amplitude of the second reference light beam with a sinusoidal signal having a frequency; on a pixel by pixel basis, detecting the substantially maximum signal level at the modulation frequency on a pixel by adjusting a second delay of the reference light beam; and determining range to a target.

System and method for glare suppression and ranging

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.

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Glendale, AZ, United States of America

Tiequn Qiu