Class / Patent application number | Description | Number of patent applications / Date published |
356461000 | Resonant loop | 41 |
20090244544 | UNIDIRECTIONAL CROW GYROSCOPE - An optical waveguide gyroscope includes at least one optical coupler configured to receive a first optical signal at a first port, to transmit a second optical signal to a second port, and to transmit a third optical signal to a third port. The optical waveguide gyroscope further includes a plurality of resonant waveguides optically coupled to the second port and the third port. The resonant waveguides are generally adjacent to one another and optically coupled to one another. At least a portion of the second optical signal propagates from the second port to the third port by propagating through the plurality of resonant waveguides, and at least a portion of the third optical signal propagates from the third port to the second port by propagating through the plurality of resonant waveguides. The at least a portion of the second optical signal propagates through each resonant waveguide of the plurality of resonant waveguides in a clockwise direction and the at least a portion of the third optical signal propagates through each resonant waveguide of the plurality of resonant waveguides in a counterclockwise direction. | 10-01-2009 |
20090296098 | RELIABLE LOW LOSS HOLLOW CORE FIBER RESONATOR - An optical coupling device for connecting hollow core optical fiber coils in a fiber optic gyro system. An example fiber optic gyro system includes a recirculator or an integrated optics chip, a fiber coil of hollow core optical fiber with first and second ends, and a coupling device that holds an end of the hollow core optical fiber in an enclosed cavity at some predefined distance from the recirculator or integrated optics chip. The coupling device includes a housing for rigidly holding the fiber end in position. The housing includes a cavity that receives the fiber end. | 12-03-2009 |
20100002239 | RFOG MODULATION ERROR CORRECTION - Systems and methods for performing modulation error correction. An example system applies common phase/frequency modulation to first and second laser beams, a first intensity modulation to the first modulated beam, and a second intensity modulation to the second modulated beam. Signals outputted are demodulated according to the frequency of the common phase/frequency modulation. Then the first of these demodulated signals is demodulated based on the frequency of the intensity modulation of the first beam, and the second of these demodulated signals is demodulated based on the frequency of the intensity modulation of the second beam. Then, rate of rotation is determined based on demodulated signals. Frequencies of the intensity modulations are unequal and not harmonically related, and intensity modulation encodes each light beam with a unique signature. | 01-07-2010 |
20100027022 | FIBER OPTIC GYROSCOPE - An improved resonator fiber-optic gyro (RFOG). An example RFOG includes a closed-coil resonator where counter-propagating laser beams are done by fiber couplers. Signals are extracted from the ring resonator using other fiber couplers. The fiber couplers may be fiber spliced couplers, free-space fiber-to-fiber coupling elements or comparable coupling devices. A silicon structure may be used to align components of the gyro or just the coupling elements. The resonator includes a hollow-core fiber. | 02-04-2010 |
20100046000 | Semiconductor ring laser gyroscope - A semiconductor ring laser gyroscope includes: a semiconductor laser for emitting two lights from both end surfaces thereof; an optical fiber ring through which the two light propagate in the respective opposite directions, which, in association with the semiconductor laser, constitutes a laser resonator, and which includes a sensor coil made of an optical fiber wound in a multilayer manner; and an optical detection unit for detecting a rotational angular velocity based on beat frequencies of the two lights, wherein an expression: 2ΔF | 02-25-2010 |
20100053631 | Fiber optic gyroscope with auxiliary function - A fiber optic gyroscope includes first and second gyroscopes. The first gyroscope includes: a first light source for emitting two lights; a first optical fiber loop which includes a sensor coil structured such that an optical fiber is wound in a multilayer manner, through which the two lights travel in opposite directions, and which constitutes a laser resonant circuit with the first light source; and a first optical detector for detecting an angular velocity based on a beat frequency which is produced by the two lights. The second gyroscope includes: a second light source for emitting light; an optical distributor for dividing the light into two lights; a second optical fiber loop through which the two lights travel in opposite directions and enter both respective ends of the sensor coil; and a second optical detector for detecting an angular velocity based on a phase difference between the two lights. | 03-04-2010 |
20100225922 | CAVITY LENGTH MODULATION IN RESONATOR FIBER OPTIC GYROSCOPES - Systems and methods for reducing rotation sensing errors in a resonator fiber optic gyroscope. An example method propagates a primary light wave through a resonator having an optical fiber and a plurality of optical surfaces for directing the light wave exiting a first end of the optical fiber back into an opposite end of the optical fiber. The optical fiber is wound onto a piezo-electric transducer (PZT) tube. A sinusoidal voltage is applied to the PZT tube to modulate a length of a fiber cavity within the optical fiber. The amplitude and frequency of the fiber cavity length modulation is selected to produce a relative phase modulation between the primary light wave and a double-back reflected light wave, such that the rotation sensing errors resulting from double backscatter of light is at a frequency above a frequency band of interest. This allows the associated error to be filtered out of the rotation rate signal. | 09-09-2010 |
20100225923 | RESIDUAL INTENSITY MODULATION (RIM) CONTROL LOOP IN A RESONATOR FIBER-OPTIC GYROSCOPE (RFOG) - Systems and methods for reducing intensity modulation-induced rotation rate measurement error in a resonator optical gyroscope. The method includes tapping an intensity modulated light beam, directing a portion of the tapped light beam toward a photo detector, outputting from the photo detector a signal proportional to the amplitude variation of the light beam, amplifying the signal, and then providing the signal to the intensity modulator as a control input. Intensity modulation-induced error is reduced by an amount proportional to the gain of the feedback loop. | 09-09-2010 |
20100290057 | COMPACT RESONATOR FIBER OPTIC GYROSCOPES - Substantially symmetric RFOG configurations for rotation rate sensing using two input/output coupling components. Configurations are disclosed where optical coupling components handles both input and output lightwaves. Reducing the number of input/output coupling components while maintaining a substantially symmetric configuration for the CW and CCW beam reduces losses, prevents realization of bias errors due to asymmetric light paths in the resonator, and produces better signal to noise performance. In addition, the invention discloses systems integrating multiple functions into compact micro-optic devices that are easier to fabricate and package, leading to compact RFOGs with reduced cost and improved manufacturability. | 11-18-2010 |
20100309475 | METHOD AND AMPLIFYING STAGE FOR SUPPRESSING MODULATION DISTORTION RATE SENSING ERRORS IN A RESONATOR FIBER OPTIC GYROSCOPE - A device and a method for suppressing 2nd order harmonic distortion in a Resonator Fiber Optic Gyroscope includes driving a laser to generate at least one of a plurality of counter propagating laser beams traveling through a fiber optic resonator according to a modulated signal. The modulated signal can be represented by a polynomial having two terms, and each of the two terms is suitably multiplied by a coefficient and a constant. A modulation amplitude adjuster amplifies the modulation signal by an amplification factor as it is used to drive the laser. When the amplification factor is suitably chosen to represent a square root of a ratio of the constants, the total harmonic distortion in the RFOG is minimized. | 12-09-2010 |
20110019198 | RESONATOR FIBER OPTIC GYROSCOPE (RFOG) WITH REDUCED BIAS ERROR FROM HIGH ORDER SPATIAL MODES - Multiple resonator fiber optic gyroscope (RFOG) configurations comprising one or more mode filters inside the resonator are adopted to effectively suppress unwanted high order spatial modes which can be a significant source of gyro bias errors. The resonator comprises at least a loop fiber, either two or more in/out coupling elements, and connectors that link elements into a circulating loop. Directional elements may be used to separate output light from input light in some of the embodiments. In all embodiments, mode filters are placed in the resonator to guarantee that the light reaching the photodetector is filtered by at least one mode filter in the resonator at least once. The mode filters may contain both spatial mode filters (such as single mode fibers or waveguides) and polarization mode filters (such as polarizing elements) so that both spatial and polarization mode filtering can be implemented simultaneously. | 01-27-2011 |
20110037985 | RESONATOR OPTICAL GYROSCOPE HAVING INPUT BEAM MODULATION OPTIMIZED FOR HIGH SENSITIVITY AND LOW BIAS - 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 J | 02-17-2011 |
20110141477 | LIGHT-PHASE-NOISE ERROR REDUCER - A resonator gyroscope comprises a reference laser generator to produce a reference light; a first slave light source to produce a first slave light locked to the reference light; a second slave light source to produce a second slave light locked to the reference light; a first optical filter cavity coupled to at least one of the first and second slave light sources to filter out high-frequency fluctuations in the respective first and second slave lights; a resonator coupled to said first and second light sources, the resonator having first and second counter-propagating directions and resonance tracking electronics coupled to the resonator to generate a first beat frequency, a second beat frequency, and a third beat frequency; wherein the rotational rate of the resonator gyroscope is a function of the first, second and third beat frequencies. | 06-16-2011 |
20110205546 | Device and Method for Vibrating a Solid Amplification Member Within a Gyrolaser - A laser gyro includes an amplifying solid element and a device for vibrating said amplifying solid element at a predetermined frequency, along an axis of revolution of said amplifying solid element. The geometry of said amplifying solid element is such that a natural mode of mechanical vibration of said amplifying solid element corresponds to said predetermined frequency. | 08-25-2011 |
20110255094 | Optical gyroscope sensors based on optical whispering gallery mode resonators - Optical gyroscope devices based on optical whispering gallery mode resonators that measure rotations based on rotation-induced optical phase shift in optical whispering gallery mode resonators. | 10-20-2011 |
20110292396 | SYSTEM AND METHOD FOR ENHANCING SIGNAL-TO-NOISE RATIO OF A RESONATOR FIBER OPTIC GYROSCOPE - A resonator fiber optic gyroscope includes a sensing resonator having a first resonance frequency for a first laser beam propagation direction and a second resonance frequency for a second laser beam propagation direction; an intensity modulator coupled to an output of the sensing resonator and configured to modulate the intensity of a signal output from the sensing resonator, wherein the intensity modulator modulates the output signal at an intensity modulation frequency; and resonance tracking electronics coupled to an output of the intensity modulator and configured to demodulate the intensity modulated signal output from the intensity modulator at a resonance tracking modulation frequency to produce a first demodulated signal; the resonance tracking electronics further configured to demodulate the first demodulated signal at the intensity modulation frequency, wherein the intensity modulation frequency is different from the resonance tracking modulation frequency. | 12-01-2011 |
20120057167 | RFOG WITH OPTICAL HETERODYNING FOR OPTICAL SIGNAL DISCRIMINATION - A RFOG comprises a reference laser configured to produce a reference laser beam; a first laser source configured to produce a first laser beam; a second laser source configured to produce a second laser beam; a sensing resonator coupled to the first and second laser sources such that the first and second laser beams propagate through the sensing resonator in first and second directions, respectively; resonance tracking electronics configured to generate first and second control signals that indicate when the first and second laser beams, respectively, are off resonance; first and second optical combiners configured to beat the first and second outputs of the sensing resonator with the reference laser beam creating first and second beat signals, respectively; wherein the resonance tracking electronics is configured to discriminate between at least one rotation-sensing error and the first and second outputs of the resonator based on the first and second beat signals. | 03-08-2012 |
20120092676 | ALL-FIBER INTERFEROMETRIC FIBER OPTIC GYROSCOPE FOR INHIBITING ZERO DRIFT - A method for inhibiting zero drift of an all-fiber interferometric fiber optic gyroscope and a corresponding all-fiber interferometric fiber optic gyroscope are disclosed. The method comprises: reversing the polarity of an AC voltage applied to a PZT piezoelectric ceramic phase modulator according to a predetermined half-cycle time period, and making half of the difference between output rotation rates of the gyroscope in two adjacent half-cycle time periods as the output rotation rate of the gyroscope in a cycle. A phase reversal switch and a DSP chip are added to the all-fiber interferometric fiber optic gyroscope. The phase reversal switch is used for controlling the polarity of the AC voltage, and the DSP chip is used for outputting a square wave signal to control the phase reversal switch and for calculating the output rotation rate of the gyroscope according to the output signal of a demodulation/amplifier circuit. | 04-19-2012 |
20120218555 | OPTICAL INGREDIENT-MEASURING APPARATUS - An optical ingredient-measuring apparatus is provided for measuring a concentration of an optically rotative substance. The apparatus includes a sensor main body which detects a phase difference between linear polarized light beams that propagate through an optical fiber loop in opposite directions, a circular polarized input component interposed in the middle of the optical fiber loop having first and second converters that convert the linear polarized light propagating through the optical fiber loop into left-hand and right-hand circular polarized light, and a concentration detector, installed in the sensor main body, which calculates the concentration of the substance in the sample based on the detected phase difference. | 08-30-2012 |
20120307253 | OPTICAL FILTERING FOR RESONATOR-FIBER-OPTIC GYROSCOPES - An optical-fiber filter is provided. The optical-fiber filter includes an optical fiber having a first end-face and an opposing second end-face. The first end-face and the second end-face set a fiber length. The first end-face and the second end-face are coated with reflective coatings. When an optical beam emitted from a laser is coupled into one of the first end-face or the second end-face, an optical beam output from the opposing end-face has a narrow linewidth and low frequency noise fluctuations. | 12-06-2012 |
20130070252 | SYSTEMS AND METHODS FOR A HOLLOW CORE RESONANT FILTER - Systems and methods for a hollow core resonant filter are provided. In one embodiment, a hollow-core fiber resonant cavity comprises: a hollow-core fiber having a first and second ends; a first and a second pigtail fiber each of solid core fiber material. A tip of the first pigtail is optically aligned with the first-end to couple light from the first pigtail to the hollow core fiber across a first free-space gap. A tip of the second pigtail is optically aligned with the second-end to couple light from the second pigtail to the hollow-core fiber across a second free-space gap. The tip of the second pigtail is coated to reflect light received from the second-end back across the second free-space gap into the second-end. The tip of the first pigtail is coated to reflect light received from the first-end back across the first free-space gap into the first-end. | 03-21-2013 |
20130107271 | SYSTEM AND METHOD FOR REDUCING ERRORS IN A RESONATOR FIBER OPTIC GYROSCOPE | 05-02-2013 |
20130271770 | RESONATOR FIBER OPTIC GYROSCOPE UTILIZING LASER FREQUENCY COMBS - A resonator fiber optic gyroscope comprises a first light source having a first frequency comb spectrum, and a second light source having a second frequency comb spectrum. A first filter is in optical communication with the first light source and configured to pass a first frequency comb portion. A second filter is in optical communication with the second light source and configured to pass a second frequency comb portion. A resonator is in optical communication with the first and second filters. The free spectral range values of the first and second frequency comb portions are adjusted to be an odd integer multiple of the free spectral range value of the resonances of the resonator. The second frequency comb portion is spectrally separated apart from the first frequency comb portion by a multiple of the free spectral range value of the resonances plus a frequency value proportional to rotation rate. | 10-17-2013 |
20140049780 | LOW NOISE RESONATOR FIBER OPTIC GYRO - A low-noise resonator fiber-optic gyroscope is provided. The low-noise resonator fiber-optic gyroscope includes at least one laser to output a reference optical beam, a first-optical-beam frequency controller to modulate the first optical beam at a first-modulation frequency, a second-optical-beam frequency controller to modulate the second optical beam at a second-modulation frequency to form a second-frequency-modulated optical beam, a fiber resonator having a counter-clockwise-input end configured to input the first-frequency-modulated optical beam and the clockwise-input end configured to input the second-frequency-modulated optical beam; a first-frequency demodulator to demodulate an optical beam output from the clockwise-input end of the fiber resonator; and a second-frequency demodulator to demodulate an optical beam output from the counter-clockwise-input end of the fiber resonator. The first-modulation frequency and the second-modulation frequency are adjusted so that sideband noise spectrum centered on the first and second modulation frequencies are from each other. | 02-20-2014 |
20140152994 | OPTICAL FREQUENCY COMB STIMULATED BRILLOUIN SCATTERING GYROSCOPE - Systems and methods for measuring rotation using an optical frequency comb stimulated Brillouin scattering gyroscope are provided. In certain embodiments, a system comprises a light source that produces a multiple-frequency light beam based on an optical frequency comb; and an optical fiber resonator coupled to the light source, the multiple-frequency light beam propagating in a first direction within the optical fiber resonator, wherein the multiple-frequency light beam generates stimulated Brillouin scattering (SBS) for a frequency, wherein the Brillouin scattering generates an SBS light beam to propagate in a second direction, the first direction being opposite in direction to the second direction. The system also comprises a servo to control the frequencies of the optical frequency comb to lock a plurality of component frequencies on resonance peaks of the optical fiber resonator; and a mixer that determines a frequency difference between the SBS light beam and the multiple-frequency light beam. | 06-05-2014 |
20140204387 | NARROW BANDWIDTH REFLECTORS FOR REDUCING STIMULATED BRILLOUIN SCATTERING IN OPTICAL CAVITIES - An optical-fiber filter system to narrow a linewidth and to reduce noise fluctuations of an optical beam is provided. The optical-fiber filter system includes an optical fiber having a first end-face and an opposing second end-face, the first end-face and the second end-face setting a fiber length; a fiber Bragg grating having a first reflectivity positioned at the first end-face; and a reflector having a second reflectivity positioned at the second end-face. When the optical beam at a first frequency is coupled from a laser into one of the first end-face or the second end-face, a resonant cavity is established at the first frequency between the fiber Bragg grating and the reflector while Brillouin scattered light shifted from the first frequency within the optical fiber is transmitted through the fiber Bragg grating. | 07-24-2014 |
20140211211 | RFOG WITH OPTICAL HETERODYNING FOR OPTICAL SIGNAL DISCRIMINATION - In one embodiment a system including a resonator fiber-optic gyroscope configured to measure rotation rate is provided. The resonator fiber-optic gyroscope includes a sensing resonator have a first resonance frequency for a first laser beam propagation direction and a second resonance frequency for a second laser beam propagation direction, an optical mixer coupled to an output of the sensing resonator and configured to mix an output of the sensing resonator with a reference laser, wherein the optical mixer outputs a beat signal, and a resonance tracking electronics coupled to the optical mixer. The resonance tracking electronics are configured to demodulate the beat signal at a frequency offset to produce first in-phase and quadrature demodulated information, generate R-squared information from a sum of squares of the first in-phase and quadrature demodulated information, and demodulate the R-squared information at a resonance tracking modulation frequency. | 07-31-2014 |
20140240712 | METHOD AND SYSTEM FOR DETECTING OPTICAL RING RESONATOR RESONANCE FREQUENCIES AND FREE SPECTRAL RANGE TO REDUCE THE NUMBER OF LASERS IN A RESONATOR FIBER OPTIC GYROSCOPE - A resonator fiber optic gyroscope (RFOG) is provided. The RFOG includes a gyroscope resonator having a clockwise input port and a counter-clockwise input port; a first laser configured to couple a clockwise optical beam into to the clockwise input port; a clockwise Pound-Drever-Hall modulation generator to modulate the clockwise optical beam with a resonance tracking modulation before the clockwise optical beam is coupled into the clockwise input port; bias correction electronics; FSR-detection-and-servo electronics including a switch communicatively coupled to the clockwise Pound-Drever-Hall modulation generator; a clockwise transmission detector configured to receive an optical beam output from the counter-clockwise input port and output signals to the bias correction electronics and the FSR-detection-and-servo electronics; and a second laser configured to couple a counter-clockwise optical beam into to the counter-clockwise input port, wherein the FSR of the gyroscope resonator is measured based on the Pound-Drever-Hall modulation of the clockwise optical beam. | 08-28-2014 |
20150015892 | RFOG WITH LOW CHROMATIC DISPERSION - One embodiment is directed towards a resonator fiber optic gyroscope (RFOG) including a resonator, one or more light sources coupled to the resonator, and resonance tracking electronics coupled to the resonator. The one or more light sources are configured to produce at least two light beams for input into the fiber coil, the at least two light beams including a first light beam at a first frequency and a second light beam at a second frequency, the first and second frequencies locked to nearby resonance modes of the resonator. The resonance tracking electronics are configured to process output light from the resonator and generate a signal therefrom, the signal indicative of a rotation rate of the resonator. The fiber coil has approximately zero total accumulated chromatic dispersion at the first frequency and the second frequency of the first light beam and the second light beam. | 01-15-2015 |
20150070707 | LASER WITH TRANSMISSION AND REFLECTION MODE FEEDBACK CONTROL - One embodiment is directed towards a stabilized laser including a laser to produce light at a frequency and a resonator coupled to the laser such that the light from the laser circulates therethrough. The laser also includes Pound-Drever-Hall (PDH) feedback electronics configured to adjust the frequency of the light from the laser to reduce phase noise in response to light sensed at the reflection port of the resonator and transmission port feedback electronics configured to adjust the frequency of the light from the laser toward resonance of the resonator at the transmission port in response to the light sensed at the transmission port of the resonator, wherein the transmission port feedback electronics adjust the frequency at a rate at least ten times slower than the PDH feedback electronics. | 03-12-2015 |
20150098088 | METHODS AND APPARATUS OF TRACKING/LOCKING RESONATOR FREE SPECTRAL RANGE AND ITS APPLICATION IN RESONATOR FIBER OPTIC GYROSCOPE - 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+0.5) times the modulation frequency of the clockwise optical beam through the second servo. | 04-09-2015 |
20150316382 | SYSTEMS AND METHODS FOR AN INTENSITY STABILIZED RESONATOR FIBER OPTIC GYROSCOPE - 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. | 11-05-2015 |
20150362318 | SAGNAC EFFECT BASED RADIO FREQUENCY ELECTRONIC GYROSCOPE INCORPORATED IN CMOS INTEGRATED CIRCUIT - A radio frequency based electronic gyroscope function that may be incorporated in its entirety on a monolithic integrated circuit (IC). The detection and measurement of movement in a particular plane is based on the Sagnac effect as it applies to a radio frequency signal that propagates in two different directions in a loop that may be subject to rotational perturbation. In one embodiment, three mutually perpendicular loops that are incorporated into the same integrated circuit and are used to detect and measure movement in three planes (roll, pitch and yaw) thereby allowing a signal processing unit to quantify a general three dimensional movement. The gyroscope can be incorporated into an IC that is used in portable device, such as a mobile handset, to provide it with inertial navigation and movement detection and measurement capabilities. | 12-17-2015 |
20150369605 | SYMMETRIC THREE-LASER RESONATOR FIBER OPTIC GYROSCOPE - 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. | 12-24-2015 |
20150369606 | SMALL LOW COST RESONATOR FIBER OPTIC GYROSCOPE WITH REDUCED OPTICAL ERRORS - 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. | 12-24-2015 |
20160003619 | RESONATOR FIBER OPTIC GYROSCOPE EMPLOYING COMMON CAVITY LENGTH MODULATION ALONG WITH HIGH BANDWIDTH LASER STABILIZATION - A resonator fiber optic gyroscope comprises a master laser device that emits a reference optical signal, a first slave laser device that emits a clockwise optical signal, and a second slave laser device that emits a counter-clockwise optical signal. A resonator ring cavity is in communication with the master laser device and the slave laser devices. A sine wave generator is coupled to the resonator ring cavity and outputs a common cavity modulation frequency comprising in-phase and quadrature signals. A laser stabilization servo receives a clockwise reflection signal that includes the common cavity modulation frequency from the resonator ring cavity. A modulation stripper coupled to the servo receives the in-phase and quadrature signals, receives a net error signal from the servo, demodulates the net error signal at the common cavity modulation frequency, and transmits a stripper signal to the servo to remove the signal at the common cavity modulation frequency. | 01-07-2016 |
20160025494 | FIBRE-OPTIC INTERFEROMETRIC MEASUREMENT DEVICE COMPRISING A RING RESONATOR, GYROMETER AND INERTIAL ATTITUDE OR NAVIGATION UNIT COMPRISING SUCH A DEVICE - A fibre-optic interferometric measurement device ( | 01-28-2016 |
20160047655 | RESONANT FIBER OPTIC GYROSCOPE WITH POLARIZING CRYSTAL WAVEGUIDE COUPLER - 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. | 02-18-2016 |
20160069687 | Optical Rotation Sensor As Well As Method Of Manufacturing An Optical Rotation Sensor - An optical rotation sensor is provided, comprising an optical ring resonator (RR) formed by a one-dimensional photonic crystal (1D PhC) waveguide, and a bus waveguide. A light input section of the bus waveguide is connectable to a light source, and a light output section of the bus waveguide is connectable to a light detector. The bus waveguide is optically coupled to the ring resonator within a coupling area which is located between the light input section and the light output section of the bus waveguide. The optical rotation sensor is configured to measure a shift of frequency of a resonance area (or a plurality of resonance areas) close to a band edge of a photonic band gap of the ring resonator, wherein the shift of frequency is caused by a rotation of the optical rotation sensor. | 03-10-2016 |
20160116288 | ANGULAR VELOCITY DETECTION METHOD ADOPTING BI-DIRECTIONAL FULL RECIPROCAL COUPLING OPTOELECTRONIC OSCILLATOR - The present invention provides an angular velocity detection method adopting a bi-directional full reciprocal coupling optoelectronic oscillator, which is implemented on an optical carrier microwave gyroscope. The optical carrier microwave gyroscope is a bi-directional resonant optical carrier microwave angular velocity measurement device sharing one optical fiber loop. The core of the method lies in that the Sagnac effect is sensed using a bi-directional optical carrier microwave resonant cavity, where the optical carrier microwave resonant cavity employs a coupling optoelectronic oscillator to achieve a bi-directional full reciprocal optical fiber path, and non-reciprocity error of the resonant cavity is eliminated effectively. The angular velocity detection method has features of high-precision, easy implementation and low costs. | 04-28-2016 |
20160204571 | SYSTEMS AND METHODS FOR AN OPTICAL FREQUENCY COMB STIMULATED BRILLOUIN SCATTERING GYROSCOPE WITH RIGID OPTICAL WAVEGUIDE RESONATOR | 07-14-2016 |