182 results about "Optical gyroscope" patented technology

Methods and apparatus are provided for determining the rotational rate of an optical gyro. An optical gyro comprises at least one substrate, a multi-frequency light source (MFLS) mounted on the substrate, and a resonator coupled to the MFLS. The MFLS is configured to produce a first light beam having a first frequency and a second light beam having a second frequency and phase locked with the first light beam. The resonator comprises an optical fiber coil having a hollow core. The resonator is configured to circulate a portion of each of the first and second light beams through the hollow core. The portion of the first light beam propagates in a first counter-propagating direction, and the portion of the second light beam propagates in a second counter-propagating direction. A measured difference between the first and second frequencies indicates a frequency shift proportional to the rotation rate of the optical gyro.

The invention discloses a device and a method for detecting a micro resonant mode optical gyro in dual-signal combined modulation. The method comprises the following steps: firstly, carrying out the dual-signal combined modulation to a laser input into the chip of a micro optical ring-shaped resonant cavity, and synchronously demodulating the clockwise and counterclockwise output signals of the optical ring-shaped resonant cavity, wherein, one demodulated signal controls the frequency of a laser device through a servo loop, so that the frequency of the output light of the laser device can be tracked and locked on the resonant frequency; and the other demodulated signal extracts the difference of the two resonant frequencies and outputs the difference as a gyro signal. The invention is favorable for realizing the micro resonant mode optical gyro in an integrated optical device and the miniaturization of the system, improves the output signal-to-noise ratio of the micro resonant mode optical gyro, suppresses the noise caused by backscattering, and reduces the control precision in modulation amplitude required by the system and improves the stability of the system at the same time.

A method for enhancing a sensitivity of an optical sensor having an optical cavity counter-propagates beams of pump light within the optical cavity to produce scattered light based on Stimulated Brullion Scattering (SBS). The properties of the pump light are selected to generate fast-light conditions for the scattered light, such that the scattered light includes counter-propagating beams of fast light. The method prevents the pump light from resonating within the optical cavity, while allowing the scattered light to resonate within the optical cavity. At least portions of the scattered light are interfered outside of the optical cavity to produce a beat note for a measurement of the optical sensor. The disclosed method is particularly applicable to optical gyroscopes.

A system and method for reducing coherent backscattering-induced errors in an optical gyroscope is provided. A first time-dependent phase modulation is applied to a first laser signal and a second phase modulation is applied to a second laser signal. The phase-modulated first laser signal propagates in a first direction through a waveguide coil and the phase-modulated second laser signal propagates in a second direction opposite the first direction through the waveguide coil. The first time-dependent phase modulation is applied to the phase-modulated second laser signal after the phase-modulated second laser signal propagates through the waveguide coil to produce a twice-phase-modulated second laser signal. The second time-dependent phase modulation is applied to the phase-modulated first laser signal after the phase-modulated first laser signal propagates through the waveguide coil to produce a twice-phase-modulated first laser signal. The twice-phase-modulated first and second laser signals are transmitted to a detector.

Systems and methods for optimizing input beam modulation for high gyro sensitivity and low bias errors. The present invention is a resonator optical gyroscope having an optimized phase-modulation amplitude (frequency) for a selected modulation frequency (amplitude) that maximizes the gyro signal-to-noise (S / N) sensitivity. For selected values of the phase modulation amplitude, the polarization cross-coupling induced intensity modulation can be nulled. By setting the phase modulation amplitudes substantially close to these nulling points (e.g. M=3.832 or 7.016 radians, which causes the first order Bessel function to be zero J1(M)=0) and then optimizing the modulation frequency, the intensity modulation induced bias is reduced to zero and gyro S / N sensitivity is maximized.

The invention discloses heterodyne technology based device and method for testing the half-wave voltage of a phase modulator. The device comprises a laser, a first 50-percent coupler, a phase modulator, an acousto-optic frequency shifter, a second 50-percent coupler, a photoelectric detector, a vector analyzer, a first signal generator and a second signal generator; the laser is sequentially connected with the first 50-percent coupler, the phase modulator, the second 50-percent coupler, the photoelectric detector and the vector analyzer, the first 50-percent coupler is sequentially connected with the acousto-optic frequency shifter and the second 50-percent coupler, the phase modulator is connected with the first signal generator, and the acousto-optic frequency shifter is connected with the second signal generator. The invention provides the method for accurately testing the half-wave voltage of the phase modulator, the carrier component in phase modulation can be effectively inhabited by utilizing the half-wave voltage obtained through testing, the back-scattered noise in a resonance type optical gyroscope is reduced, the invention provides a feasible method for improving the precision of the resonance type optical gyroscope and has important scientific meanings and application value.

The invention belongs to a fiber optical gyroscope, and relates to a closed loop fiber optic gyroscope scale factor high precision calibrating method. The closed loop fiber optic gyroscope scale factor high precision calibrating method comprises the following steps: fixing a product on the surface of a rotary table with an incubator, maintaining the temperature of the incubator for a period of time, carrying out power-on test on the product, inputting a constant angle rate through the rotary table, changing the temperature of the incubator, and using a variable temperature technology to obtain a calibration curve of point-to-point variation of a closed loop fiber optic gyroscope scale factor with the temperature. The method has the advantages of simple operation, low cost, high precision and large practical application values.

The invention is a compact optical gyroscope based on the Sagnac effect that combines a micro-ring cavity laser comprising a magneto-optical material and a magnetic field to circumvent the lock-in phenomenon at low rates of rotation. The invention also embodies novel processes for breaking lock-in using a transverse Faraday effect.

The present invention relates to a method for detecting deformation of underwater engineering structure based on fiber-optical gyro technology and its equipment. It is formed from fibre-optical gyroscope, line speed sensor and signal receiving and storing unit which are packaged in a closed container. Said method and its equipment utilize the characteristics of the fiber-optical gyroscope sensingangle speed, said closed container can be pulled and moved along tested object, and the data measured by said gyroscope and line speed sensor can be processed so as to obtain its I-D or 3-D movement trace by means of calculating according to the formula, i.e. I-D or 3-D deflection and deformation of tested object.

The invention discloses a testing device and a testing method for a resonant mode optical gyroscope scale factor. The device comprises a combined signal source module, a photoelectric hybrid module and a digital signal processing module. According to the device and the method, the resonant mode optical gyroscope scale factor can be tested without a rotary table, so that the dependence on the rotary table is got rid off when the resonant mode optical gyroscope scale factor is tested, the influence of vibration of the rotary table on the gyroscope scale factor is avoided, and the testing accuracy of the resonant mode optical gyroscope scale factor is improved. Compared with the traditional scale factor testing method, the method is simple and convenient to operate, and can improve the testing efficiency of the resonant mode optical gyroscope scale factor.

A fiber-optic sensor, a method of configuring a fiber-optic sensor, and a method of using a fiber-optic sensor are provided. The fiber-optic sensor includes an optical fiber coil having a length and a laser source optically coupled to the coil. The laser source has a coherence length. Light from the source is transmitted to the coil as a first signal propagating along the coil in a first direction and a second signal propagating along the coil in a second direction opposite to the first direction. The optical paths of the first signal and the second signal are substantially reciprocal with one another and the first signal and the second signal are combined together after propagating through the coil to generate a third signal. The coherence length is greater than 1 meter or is in a range between 200 microns and 10 centimeters.

A photonic crystal interferometric optical gyroscope system including a light source for providing a primary beam of light, a photonic crystal sensing coil having a rotational axis, and a beam controlling device configured to split the primary beam into first and second counter-propagating beams in the photonic crystal sensing coil and configured to direct return of the counter-propagating beams wherein the power of the returning counter-propagating beams represents the phase shift between the counter-propagating beams and is indicative of the rate of rotation of the coil about the rotational axis.

The invention relates to a systematic compensation method of fixed-precision navigation of a ship optical inertial navigation system when in long voyage. The method comprises the following steps: step I, determining a coordinate system of a ship, and marking the head direction of the system; step II, installing an optical gyroscope and a gauge on a high-strength high-precision hexagonal body; step III, debugging a single-shaft rotating mechanism control system, and designing a transposition scheme by utilizing a mature PID control algorithm; step IV, fixedly installing an IMU to a table-board of a transposition mechanism; step V, acquiring original data of a strap-down inertial navigation system, processing the acquired data, such as temperature compensation, sailing direction effect compensation, systematic calibration and the like; step VI, updating an attitude and calculating speed and position in the design of a pure inertial system in a single-shaft rotating modulation system; and step VII, demodulating the single-shaft rotation in real time. The constant high precision and stability of the inertial navigation system on a working carrier when a water ship is in long voyage can be guaranteed.

The interferential silicon chip micro optical gyroscope has successively connected detector, sample circuit, DSP circuit, modulating driver circuit, Y-waveguide modulator, beam splitter, light source, and spiral light waveguide with upper layer spiral light waveguide, lower layer spiral light waveguide and Si substrate for spiral light waveguide. The present invention is superior to optical fiber gyroscope, which has great fiber length and great temperature and vibration influence, and has small size, high reliability and high precision. The present invention is also superior to micro mechanical gyroscope, and has light source, optical device and processing circuit integrated on one chip and thus high precision and high reliability.

The invention relates to a biaxial optical gyroscope, which consists of a surface plasma excimer Y-type mode separator, a Y waveguide integrated optical device, a Y waveguide integrated optical chip, a first polarization-preserving fiber coil, a second polarization-preserving fiber coil, a directional coupler and a detector. The invention belongs to the technical field of integrated optics and inertial sensor, and provides the biaxial optical gyroscope. The biaxial optical gyroscope with a separation mode is realized by adopting waveguide devices made of different materials, and has the advantages of improvement on the utilization rate of light sources, high integrity and the like.

The invention discloses a resonator optical gyroscope based on resonant intracavity modulation. The resonator optical gyroscope comprises a light source, an isolator, a coupler C0, a coupler C1, a coupler C2, an inactive Y-branch coupler, a resonant cavity, a modulator, a first prober, a second prober, a first signal processing circuit, a second signal processing circuit and a modulation signal output circuit. The gyroscope provided by the invention uses the resonant intracavity modulation to replace an external two-circuit modulator structure, so that a gyroscope model is simplified and the integration degree of the gyroscope is greatly improved. The resonance characteristic of the resonant cavity provided by the invention enhances the modulation characteristic, so that a modulation voltage is reduced. Furthermore, the gyroscope provided by the invention is only provided with a modulation arm, however, a double modulation effect is achieved and the power consumption of the system is reduced. The modulation manner corresponding to the intracavity modulation provided by the invention uses a simple periodic square wave modulation curve, so that the non-linear error of the triangular wave is removed when being compared with the triangular wave modulation curve which is commonly used in external modulation; the asymmetry of a waveform is avoided; the gyroscope is beneficial to improvement on the entire precision of the gyroscope.

A method for compensating output angular speed information of optical fiber gyroscope in temperature-control free and closed loop light source type includes applying regression analysis means to obtain adapting relation of central wavelength of outgoing light from temperature-control free light source to temperature then compensating optical gyroscope output angular speed information drift caused by temperature variation in utilizing optical gyroscope to output relevant relation value of central wavelength at outgoing light on temperature-control free light source.

The invention is a compact optical gyroscope based on the Sagnac effect that combines a micro-ring cavity laser comprising a magneto-optical material and a magnetic field to circumvent the lock-in phenomenon at low rates of rotation. The invention also embodies novel processes for breaking lock-in using a transverse Faraday effect.

The invention provides a resonant mode optical gyroscope signal detection device and method based on a virtual instrument, belonging to the technical field of optical gyroscope signal detection. The resonant mode optical gyroscope signal detection device comprises a signal modulating module, a collection unit A, a collection unit B, an FPGA (Field Programmable Gate Array) control unit and a computer based on a PXIe (Pci Express-extensions-for-instrumentation) bus; an object to be detected is a photoelectric mixing module; and the photoelectric mixing module comprises a first detector, a second detector, an integrated optical phase modulator and a light source. According to the invention, modularized hardware of the virtual instrument is used for replacing a traditional detection circuit, hardware developing time is shortened, circuit noise is small, the anti-jamming capability is strong and the gyroscope precision is improved. Digital signal processing of a resonant mode optical gyroscope is carried out on FPGA programming based on labview virtual instrument software; and the verification of an algorithm can be rapidly carried out according to abundant resources in an FPGA and the flexibility of labview graphics programming, so as to accelerate a research speed of the resonant mode optical gyroscope.

The invention discloses a frequency code optical fiber time domain reflectometer and a working method thereof. The frequency code optical fiber time domain reflectometer comprises a light source, a first optical fiber coupler, an acoustic optical modulator, a radio frequency signal generator, an optical fiber amplifier, an optical gyroscope, a second optical fiber coupler, a balance detector and a data acquisition card. Optical pulses are subjected to frequency modulation so that the space resolution ratio is not limited by optical pulse lasting time and the space resolution ratio does not depend on the width of the pulse, but depends on a frequency modulation range of detection pulses, so that the aims of high space resolution ratio and long detection distance are realized simultaneously.

The invention discloses a device for testing basic structural parameters of an annular resonant cavity of an optical waveguide and a method thereof. The method comprises the following steps of: designing three reference straight waveguides with identical structure on an annular resonant cavity chip of the optical waveguide, coupling by an optical fiber coupler and testing the resonance curve of the annular cavity and the average output amplitude of the reference straight waveguides to obtain the specific values of all structural parameters of the annular resonant cavity of the optical waveguide, including coupling coefficient and additional loss of the coupler as well as transmission loss of the waveguides. The device for acquiring structural parameters of the annular resonant cavity of the optical waveguide comprises a sawtooth wave signal generator, which is sequentially connected with a laser, an annular resonant cavity chip of the optical waveguide, a PD detector, an oscilloscope and a computer. The invention can nondestructively, easily and directly acquire three basic structural parameters of the annular resonant cavity of the optical waveguide, which provides instruction for further designing high-performance resonant cavity of optical waveguide. Meanwhile, the invention has important scientific meanings and application values in improving limit sensitivity and performance of resonant micro-optical gyroscope.

Methods and apparatus are provided for a low cost optical gyro with a free space closed optical path. A ring resonator comprises a substrate and reflectors formed or placed on the substrate. The reflectors comprise a closed optical path and are configured to direct each of first and second light beams in a different counter-propagating direction in the closed optical path. Each of the first and second light beams frequencies are tuned to the resonance frequency of the resonator in the direction of propagation for which the light beam is circulating in the closed optical path.

A non-interference optical gyroscope and rotation sensing method based on a polarization sensing technique are disclosed. The method includes splitting a polarization input beam into a first beam anda second beam, coupling the first and second beams to an input / output ports of an optical loop rotated, with the propagation directions of the first beam and the second beam being contrary; combiningthe first and second beams into a combined beam; detecting polarization information of light output; providing closed feedback loop control by adopting the light output of the optical loop as a feedback so as to generate a feedback control signal; modulating the phase of at least one of the first and second beams into the optical loop by utilizing a phase modulator in a closed feedback loop; applying the feedback control signal to the phase modulator to allow a phase difference between opposite propagation signals in the optical loop to be zero or a difference between the phase difference andzero to be smaller than a preset value; and determining rotation the optical loop had undergone according to the polarization information of light output.

The invention discloses a detection method for resonant optical gyro signals, which comprises: modulating the light frequency of the light emitted by the light source both in the clockwise direction and the counterclockwise direction when the gyro works; demodulating a curve by a modulation method; demodulating the corresponding light intensity values of the frequencies of the two-path light on the curve; deriving a common modulus and a difference modulus based on the light intensity values; demodulating light source frequency offset based on the common modulus; returning the light source frequency offset to the light source; locking the two-path light frequencies by regulating the output frequency of the light source; demodulating the frequency difference of the two-path light based on the difference modulus; detecting the rotating angular velocity of the gyro. The method of the invention can effectively increase the corresponding speed of gyro output, measure the rotating angular velocity of the gyro in time and reduce noise.

The invention discloses a resonant optical gyroscope simulation method, comprising steps of 1) initializing a global time signal required by simulation; 2) providing the global time signal in the step 1) to various data signals on a computer simulation platform; 3) setting parameters involved in data signal process in the simulation task; 4) setting a simulation time length of simulation system; 5) starting system simulation to process signals; 6) observing and storing simulation results; 7) analyzing simulation result in the step 6) 8) changing simulation parameters for continuous simulation or simulation realized. The invention uniforms optical process and electrooptical process in resonant optical gyroscope by packaging optical and electric apparatus as modules, which greatly reduces work load of constructing system during simulation and overcomes problem that traditional method can not reproduce various optical phenomena. The optical noise is described by compute language and influence of optical noise in simulation is added, which enhances process of optical noise.

A high-precision optical gyroscope with 1.55 um wavelength for eliminating dead area, comprising a light path unit and a circuit unit; wherein the circuit unit comprises a laser, a laser driving circuit, a detector, a low pass filter, a analog-to-digital converter and a digital signal processing circuit; the light path unit comprises a spectral filter, an optoisolator, a first wavelength division multiplexer, an Er-doped fiber, a second wavelength division multiplexer, a reflector, a coupler, a Y-waveguide integrated optical device and a fiber coil; the spectral filter outputs superfluorescence with 1.55 um wave band; the light path unit further comprises a digital-analog converter and an amplifier; the digital-analog converter, amplifier and Y-waveguide integrated optical device are packed together by a metal box to form electromagnetic shielding. The invention interferes with the electron between driving signal of the Y-waveguide integrated optical device and the signal received by the detector on the structure to isolate, thereby eliminating the dead area caused by interference.

A device for measuring the optical ring of gyroscope on-line modularity, including circuit conciliating modular, light leading-in modular, optical ring modular, the light leading-in modular provides the power and steady polarizing coherent light for the optical ring, transmits the optical interference signal to the electrical signal and exports to the circuit conciliating modular which connected with the light leading-in modular through the electric cable, which can measure, control and output the signal of the whole optical path, the measured optical ring modular is connected with the output end of the light leading-in modular through two pigtail optical fiber being protected, The measurement of the optical ring is in the actual condition of the optical gyroscope and the output and input are identical with the actual use, it not only tests the parameter of the optical ring such as depletion and reciprocity but also tests the system response in the temperature, impact and vibration.

The invention discloses a one-chip type integrated optical gyroscope and a manufacturing method thereof. The one-chip type integrated optical gyroscope comprises a light source, a Bragg grating, a Y waveguide, an annular resonant cavity, a light detector and an integrated circuit, wherein laser output by the light source is changed into narrow-line wide laser through the Bragg grating and then is divided into two beams of light by the Y waveguide to enter the annular resonant cavity; the light detector detects clockwise light strength and anticlockwise light strength of the annular resonant cavity to carry out photovoltaic conversion; and the integrated circuit is used for driving, feeding back and controlling the light source, directly modulating the light source, processing a signal output by the light detector and outputting a gyroscope signal. The method disclosed by the invention realizes the one-chip type integrated optical gyroscope based on a mixed integration technology, a light source modulation technology and bonding. According to the one-chip type integrated optical gyroscope and the manufacturing method thereof disclosed by the invention, a scheme of modulating and demodulating signals directly modulated by the light source is adopted so that key parts of the integrated optical gyroscope are possibly mixed and integrated on the same silicon base; and therefore, the size of the gyroscope is reduced and the integration degree is improved.