Waveguide includes fork with first and second bifurcated ends coupled to loop section and separated by angle determined based on velocities of portions of quantum mechanical wavefunction of atoms traveling above waveguide. Waveguide propagates blue-detuned laser having first evanescent field that repels atoms away from waveguide and red-detuned laser having second evanescent field that attracts atoms toward waveguide, together creating potential minimum/well. Laser cooling atoms, causing atoms positioned in potential minimum/well to move toward first fork section following potential minimum/well. Atomic state initialization section initializes atomic states of atoms to known ground-state configuration. Beam splitter section splits quantum mechanical waveform of each atom above surface of diverging waveguide into first portion at first velocity that travels into first end of first fork section into first loop section and second portion at second velocity that travels into second end of first fork section into first loop section.

A digital to analog converter for fiber optic gyroscope is disclosed. The digital to analog converter for fiber optic gyroscope includes a random unit generating a random number signal, a plurality of encoding units coupled with the random unit, a plurality of control units respectively one to one coupled with the plurality of encoding units, a current source array coupled with the plurality of control units, and an output load electrically connected to the current source array. Each of the plurality of encoding units converts a plurality of digital signals to a plurality of spin signals according to the random number signal. Each of the plurality of control units converts the plurality of spin signals to a plurality of logic signals. The current source array generates a total current according to the plurality of logic signals. The total current passes through the output load and forms an analog signal.

A resonant fiber optic gyroscope (RFOG) comprises two integrated photonics interfaces coupling the optical resonator coil to the multi-frequency laser source that drives the RFOG; wherein the two integrated photonics interfaces comprise a first waveguide layer and a second waveguide layer wherein the first waveguide layer comprises two waveguide branches which come together to form a single waveguide branch; the second waveguide layer comprises two waveguide branches which remain separate from each other; and wherein the waveguide structure is configured to match an integrated photonics mode to a fiber mode supported by an optical fiber.

An improved fiber-optic gyroscope (FOG) is proposed for enhancing the optical measurement sensitivity through the application of a heterodyne effect. The improved FOG is characterized by the use of a dual-injection polarization-maintaining 3×3 directional coupler which is configured to receive a pair of source light beams that are injected thereinto in a bi-directional manner. The forward-injected light beam is used to be split into a pair of interrogating beams for use by a coiled optical fiber to implement the detection and measurement of the Sagnac effect due to a rotational movement. On the other hand, the backward-injected light beam is used to be mixed with the paired interrogating beams that have passed through and returned from the coiled optical fiber to thereby provide a heterodyne effect that can boost the differential optical power amplitude of the paired interrogating beams, thereby enhancing the optical measurement sensitivity of the FOG application.

An optical phase modulating method of a multi-integrated optical circuit of an interferometric fiberoptic gyroscope with a control feedback control with a digital modulation and demodulations approach includes the step of modulating at eight modulation levels. Each modulation levels has a duration of one-quarter of a light propagation time in a fiberoptic coil.

This invention relates the inertial navigation and position systems sector, and specifically relates an optical phase modulation scheme for an interferometric fiber optic gyroscope (I-FOG), with closed-loop feedback control equipped with a digital mod/demod approach by allowing said modulation scheme to double the feedback processing speed and obtain a more accurate and linear dynamic response of the sensor when measuring rotation rate profiles characterized by high variations.

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.

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.

A resonant fiber optic gyroscope (RFOG) comprises two integrated photonics interfaces coupling the optical resonator coil to the multi-frequency laser source that drives the RFOG; wherein the two integrated photonics interfaces comprise a first waveguide layer and a second waveguide layer wherein the first waveguide layer comprises two waveguide branches which come together to form a single waveguide branch; the second waveguide layer comprises two waveguide branches which remain separate from each other; and wherein the waveguide structure is configured to match an integrated photonics mode to a fiber mode supported by an optical fiber.

A hyperbolic modulation offset reducer circuit for a resonator fiber optic gyro (RFOG) is provided. The circuit includes a first demodulation circuit that is configured to demodulate a received transmission signal from a resonator at twice a sideband heterodyne detection modulation frequency to reject signals due to backscatter. A slave resonance tracking loop of the circuit is coupled to an output of the first demodulation circuit. The slave resonance tracking loop is configured to create an offset frequency signal from the transmission signal that is applied to an optical phase lock loop of a RFOG. A hyperbolic modulator offset control loop is also coupled to the output of the first demodulation circuit. The hyperbolic modulator offset control loop is configured to create a subharmonic common modulation signal from the transmission signal that is coupled to a common phase module in a silicon photonics chip of the RFOG.