G01C19/661

SHAKEN-LATTICE MATTER-WAVE GYRO
20220236060 · 2022-07-28 · ·

A matter-wave gyro with counter-propagating traps uses three-dimensional lattices formed of interference fringes from three pairs of interfering laser beams. Particles, such as neutral atoms, ion, or molecules are cooled to a ground state near absolute zero. The resulting ultra-cold particles are loaded into the lattices. The laser beams used to form the lattices are driven according to functions that cause the lattices to counter-propagate about a closed path (Sagnac loop) N times, where a desired tradeoff between spatial resolution and temporal resolution can be achieved by choosing an appropriate integer value of N. The lattices can be extinguished so that the particles can be imaged to identify an interference pattern. A shift in the interference pattern relative to an interference pattern that would occur with zero angular momentum can be used to measure angular momentum.

PROCESS FLOW WITH WET ETCHING FOR SMOOTH SIDEWALLS IN SILICON NITRIDE WAVEGUIDES
20220082756 · 2022-03-17 ·

Aspects of the present disclosure are directed to process flow to fabricate a waveguide structure with a silicon nitride core having atomic-level smooth sidewalls achieved by wet etching instead of the conventional dry etching process.

GYROSCOPE, ELECTRONIC DEVICE AND METHOD OF DETECTING ANGULAR VELOCITY

A gyroscope, an electronic device and a method of detecting an angular velocity. The gyroscope includes: a photoelectric detector and a light source, wherein the light source is movable relative to the photoelectric detector, and light emitted by the light source is able to be irradiated onto the photoelectric detector.

KERR EFFECT REDUCTION IN SBS LASER GYROSCOPE

A method for reducing or eliminating bias instability in a SBS laser gyroscope comprises introducing a first pump signal propagating in a CW direction, and a second pump signal propagating in a CCW direction in a resonator; generating a CCW first-order SBS signal and a CW first-order SBS signal in the resonator; increasing a power level of the first pump signal above a threshold level such that the CW first-order SBS signal generates a CCW second-order SBS signal; and increasing a power level of the second pump signal above the threshold level such that the CCW first-order SBS signal generates a CW second-order SBS signal. Above the threshold level, an intensity fluctuation of the first-order SBS signals disappear and their DC power are clamped at substantially the same power level. A Kerr effect bias instability of the SBS laser gyroscope is reduced or eliminated by the clamped first-order SBS signals.

Stimulated brillouin scattering gyroscope

A stimulated Brillouin scattering gyroscope is provided. A pump laser generates continuous wave (CW) energy that travels through at least one bus waveguide to a waveguide resonator. A reflector is positioned within the waveguide resonator. The reflector is configured to pass at least some of the CW energy in a first direction and reflect at least some stimulated Brillouin scattering (SBS) energy in a second direction. A first detector is in operational communication with the at least one bus waveguide to detect CW energy. An output of the first detector used to at least adjust a pump laser frequency of the pump laser. A second detector is also in operational communication with the at least one bus waveguide. The second detector is used to determine phase shifts in detected SBS energy to determine at least rotation.

STIMULATED BRILLOUIN RING LASER GYROSCOPE WITH OPTICAL FREQUENCY OFFSET OF COUNTERPROPAGATING PUMP LASER SIGNALS

A disk resonator is pumped by counterpropagating pump signals to produce corresponding counterpropagating Brillouin laser signals. The pump laser optical frequencies are separated by a frequency offset Δν.sub.P but excite the same nominal resonator optical mode; the Brillouin laser optical frequencies are separated by a beat frequency Δν.sub.L with 0<Δν.sub.L<Δν.sub.P. A photodetector receives the Brillouin laser signals and produces an electrical signal at the beat frequency Δν.sub.L. The frequency offset Δν.sub.P can be large so enough to prevent locking of the Brillouin laser signals onto a common Brillouin laser frequency. A signal processing system derives from the beat frequency Δν.sub.L an estimated angular velocity component of the disk optical resonator about an axis substantially perpendicular to the disk optical resonator.

STIMULATED BRILLOUIN SCATTERING GYROSCOPE

A stimulated Brillouin scattering gyroscope is provided. A pump laser generates continuous wave (CW) energy that travels through at least one bus waveguide to a waveguide resonator. A reflector is positioned within the waveguide resonator. The reflector is configured to pass at least some of the CW energy in a first direction and reflect at least some stimulated Brillouin scattering (SBS) energy in a second direction. A first detector is in operational communication with the at least one bus waveguide to detect CW energy. An output of the first detector used to at least adjust a pump laser frequency of the pump laser. A second detector is also in operational communication with the at least one bus waveguide. The second detector is used to determine phase shifts in detected SBS energy to determine at least rotation.

Apparatus and method for an optical resonator with an integrated Bragg grating

An apparatus is provided. The apparatus comprises: an optical resonator including a surface; wherein a Bragg grating is formed at least part of the surface of the optical resonator; and wherein the Bragg grating has a Bragg frequency substantially equal to a center frequency of an Nth order Brillouin gain region capable of generating an Nth order Stokes signal.

RFOG resonance hopping

Systems and methods for performing resonator fiber optic gyroscope (RFOG) resonance hopping are described herein. For example, an RFOG includes a fiber optic resonator. The RFOG also includes a plurality of laser sources that each launch a respective laser for propagation within the fiber optic resonator. Further, the RFOG includes a threshold detector that determines when the operation of at least one laser source in the plurality of laser sources exceeds a threshold associated with the operational range of an aspect of the at least one laser source. Additionally, the RFOG includes a hop control logic that adjusts the frequency of at least one laser produced by the at least one laser source one or more resonant modes of the fiber optic resonator such that the aspect of the at least one laser moves away from the threshold towards a nominal value within the operational range.

Interlaced spiral optical gyroscope

An optical gyroscope includes, in part, an optical switch, a pair of spiral optical rings and a pair of photodetectors. The optical switch supplies a laser beam. The first spiral optical ring delivers a first portion of the beam in a clockwise direction during the first half of a period, and a first portion of the beam in a counter clockwise direction during the second half of the period. The second spiral optical ring delivers a second portion of the beam in a counter clockwise direction during the first half of the period, and a second portion of the beam in a clockwise direction during the second half of the period. The first photodetector receives the beams delivered by the first and second optical rings during the first half of the period. The second photodetector receives the beams delivered by the first and second optical rings during the second half of the period.