Abstract: The optical distance measurement device is configured to include an optical interference unit for separating the reflected light into a reflected light of a first polarized wave and a reflected light of a second polarized wave, extracting first and second components orthogonal to each other from an interference light of the reflected light of the first polarized wave and the reference light, and extracting third and fourth components orthogonal to each other from an interference light of the reflected light of the second polarized wave and the reference light, and a polarization rotation unit for acquiring one or more components of horizontal and vertical components of a polarized wave by rotating a polarization angle of a first complex signal having the first and second components and a polarization angle of a second complex signal having the third and fourth components, so that a distance calculation unit calculates, on the basis of the components acquired by the polarization rotation unit, a difference bet

Abstract: An acceleration transducer defines a rectangular coordinate system with two orthogonal horizontal axes that are both normal to a vertical axis and includes a main body disposed within a housing and defining tangential side faces arranged tangentially to the vertical axis, and a normal side face arranged normally to the vertical axis. A piezoelectric element is secured to one of the tangential side faces, and a seismic mass secured to the piezoelectric element. A signal output is attached to the housing and includes a signal conductor spaced apart by an assembly gap from a tangential side face that is not attached to the piezoelectric element. The assembly gap extends perpendicularly to the vertical axis. The normal side face includes main body output conductors spanning the assembly gap in a direction perpendicular to the vertical axis and directly contacting the signal conductor.

Abstract: An acceleration transducer defines a rectangular coordinate system with two orthogonal horizontal axes that are both normal to a vertical axis and includes a main body defining tangential side faces arranged tangentially to the vertical axis, and normal side faces arranged normally to the vertical axis. The transducer includes a converter unit, exactly three piezoelectric elements and three seismic masses. Each piezoelectric element generates piezoelectric charges transmitted to the converter unit, which is only and directly arranged on a normal side face of the main body or only on a support that is attached to a normal side face of the main body. Exactly one piezoelectric element is secured to each of the three tangential side faces, and exactly one seismic mass is secured to each of the three piezoelectric elements.

Abstract: An acceleration transducer defines a rectangular coordinate system with two orthogonal horizontal axes that are both normal to a vertical axis and includes a main body defining tangential side faces arranged tangentially to the vertical axis, and normal side faces arranged normally to the vertical axis. The transducer includes exactly three piezoelectric elements and three seismic masses. Exactly one piezoelectric element is secured to each of the three tangential side faces, and exactly one seismic mass is secured to each of the three piezoelectric elements. Each piezoelectric element has a high sensitivity for a shear force exerted by the attached seismic mass along a principal tangential axis that is another one of the three axes for each of the three piezoelectric elements.

Abstract: A light detection and ranging (LiDAR) core is provided that transmits optical beams, and detects return optical beams. The transmitted optical beams are antiphase chirps that sweep a frequency band, and the sweep of the antiphase chirps includes multiple sub-sweeps over respective sub-bands of the frequency band. The system routes the transmitted optical beams that are launched towards a target, and receives light incident upon the target into the return optical beams. The system simultaneously measures and thereby produces multiple simultaneous measurements of first and second beat frequencies per sweep of the antiphase chirps, from the transmitted and returned optical beams, and includes a simultaneous measurement of the first and second beat frequencies per sub-sweep of the multiple sub-sweeps. And the system determines a range and velocity of the target from the multiple simultaneous measurements of the first and second beat frequencies per sweep of the antiphase chirps.

Abstract: Embodiments of the present disclosure are directed towards a micro-electromechanical system (MEMS) sensing apparatus, including a laser arrangement configured to generate a light beam, a first waveguide configured to receive and output the light beam, and a second waveguide aligned endface to endface with the first waveguide. The second waveguide may be configured to receive at least a portion of the light beam from the first waveguide via optical coupling through the aligned endfaces. Either the first or second waveguide may be configured to be moveable in response to an inertial change of the apparatus, wherein movement of the first or second waveguide causes a corresponding change in light intensity of the portion of the light beam, the change in light intensity indicating a measure of the inertial change. Other embodiments may be described and/or claimed.

Abstract: One embodiment includes an accelerometer system. The system includes a laser configured to emit an optical beam at a linear polarization. The system also includes an optical cavity system. The optical cavity system includes a minor that is coupled to an accelerometer housing via a spring and is configured to reflect the optical beam. The optical cavity system also includes at least one photodetector configured to receive at least a portion of at least one of the optical beam and the reflected optical beam and to generate an acceleration signal that is indicative of motion of the mirror resulting from an external acceleration acting upon the accelerometer housing. The system further includes an acceleration processor configured to calculate a magnitude of the external acceleration based on the acceleration signal.

Abstract: A method of measuring acceleration using an optical sensor. In the optical sensor, acceleration, acoustic velocity, or displacement (vibration) causes a corresponding shift in the center wavelength of the sensor output. The sensor can be coupled to a high-speed interferometric interrogator through an unbalanced fiber interferometer. The unbalanced interferometer functions to translate optical wavelength shift into phase shift, which is easily demodulated by the interrogator.

Abstract: An optical sensor in which acceleration, acoustic velocity, or displacement (vibration) causes a corresponding shift in the center wavelength of the sensor output. The sensor can be coupled to a high-speed interferometric interrogator through an unbalanced fiber interferometer. The unbalanced interferometer functions to translate optical wavelength shift into phase shift, which is easily demodulated by the interrogator. A method of measuring acceleration uses the sensor.

Abstract: The present invention relates to a method and apparatus for determining phase sensitivity of an accelerometer based on an analysis of the harmonic components of the interference signal, which can estimate phase lags of an accelerometer through an analysis of the interference signal obtained using a single photo-detector when the accelerometer moves in sinusoidal motion with an initial phase of vibration. The method comprises the steps of obtaining an interference signal in a time domain generated from a signal reflected by an accelerometer and a fixed mirror using a single photo-detector; transforming the interference signal in the time domain into a signal in a frequency domain including a plurality of harmonic signals by Fourier transform; and determining the phase sensitivity of the accelerometer using initial phase of vibration displacement of the accelerometer, which is included in the interference signal in the frequency domain.

Abstract: An optical sensor in which acceleration, acoustic velocity, or displacement (vibration) causes a corresponding shift in the center wavelength of the sensor output. The sensor can be coupled to a high-speed interferometric interrogator through an unbalanced fiber interferometer. The unbalanced interferometer functions to translate optical wavelength shift into phase shift, which is easily demodulated by the interrogator. A method of measuring acceleration uses the sensor.

Abstract: A sensor adapted for measuring acceleration, the sensor including a light source for illuminating an optical cavity; the optical cavity oriented for receiving light from the source, the optical cavity comprising a quality factor greater than or equal to about 10,000; and a photodetector for measuring a resonant frequency of light emitted from the optical cavity.

Abstract: Sensing vehicle speed is disclosed. A speed sensor is self powered. The speed sensor measures a speed data of multiple vehicles with one Doppler pulse. A sample is taken of speed sensor data from the speed sensor. The sample of speed sensor data is processed to calculate speed. The calculated speed is wirelessly transmitted to a server.

Abstract: A sensor adapted for measuring acceleration, the sensor including a light source for illuminating an optical cavity; the optical cavity oriented for receiving light from the source, the optical cavity comprising a quality factor greater than or equal to about 10,000; and a photodetector for measuring a resonant frequency of light emitted from the optical cavity.

Abstract: An optical accelerometer, gravitometer, and gradiometer have a light source, a beam splitter, a light medium, and a plurality of mirrors. The light beam from the light source is split into two beams that counter-propagate through the accelerometer. The acceleration experienced by the accelerometer causes a phase shift in the beams, and this phase shift is used to calculate the acceleration.

Abstract: This disclosure presents a non-contact precision optical device, including methods for measuring distances to an arbitrary target and various configuration geometries, for using polarization maintaining (PM) optical fiber components in a polarization diplexing scheme to construct a version of a dual chirp coherent laser radar that is immune to environmental effects.

Abstract: A proof mass is suspended in a cavity in a housing. The proof mass moves along a sensing axis in response to linear acceleration. Elastic support members are connected between the proof mass and the housing and are arranged to exert a reaction force on the proof mass in response to displacement of the proof mass along the sensing axis. An optical fiber is connected between the proof mass and opposite sidewall portions of the housing such that displacement of the proof mass along the sensing axis elongates a first portion of the optical fiber and shortens another portion. An optical signal source provides a broadband optical signal input to the optical fiber. A fiber optic Bragg grating is formed in the optical fiber and arranged to reflect a portion of the optical signal. Acceleration of the proof mass modulates the wavelength of the reflected optical signal.

Abstract: A highly sensitive accelerometer for determining the acceleration of a structure includes a mass within a housing rotationally supported by a hinge and opposing support members. The support members are alternately wound around a fixed mandrel and the mass in a pendulum arrangement. At least a portion of one of the support members comprises a transducer capable measuring the rotation of the mass within the housing. An embodiment of the invention employs optical fiber coils as support members for use in interferometric sensing processes. Arrays of such interferometer based accelerometers maybe multiplexed using WDM or similar methods.

Abstract: An acceleration transducer for use in an accelerometer includes a proof mass that comprises a transmissive optics device arranged to receive an optical signal such that the optical signal propagates through the transmissive optics device along a first optical path having a selected optical path length. A support assembly is arranged to support the proof mass such that the transmissive optics device moves from a reference position along a selected sensing axis in response to an acceleration of the proof mass along the selected sensing axis and produces an optical path length change that indicates the acceleration.

Abstract: A system and method for measuring acceleration using a fiber optic accelerometer having a pair of fiber optic coils positioned around a deformable support structure. The support structure possesses a nominally cylindrical shape with the fiber optic coils being wound around opposite ends of the cylindrical support structure from each other. The support structure deforms from its nominally cylindrical shape to a conical shape in response to acceleration along a sensing axis. The changing shape of the support structure causes one of the fiber optic coils to expand while the other of the fiber optic coils contracts. The fiber optic coils are included in an interferometer such that acceleration along the sensing axis produces a phase difference between light signals propagating in the fiber optic coils resulting from their expansion and contraction.

Abstract: A method for measuring acceleration uses an accelerometer apparatus having an optically transparent, stress-birefringent material, a source of polarized light positioned to direct a polarized beam of light into the optically transparent, stress-birefringent material, and a detector system positioned to detect an output beam from the optically transparent, stress-birefringent material. The accelerometer apparatus is accelerated, and the acceleration of the accelerometer apparatus is simultaneously determined from a measurement of stress-induced optical birefringence in the optically transparent, stress-birefringent material.

Abstract: An ultrananocrystalline diamond (UNCD) element formed in a cantilever configuration is used in a highly sensitive, ultra-small sensor for measuring acceleration, shock, vibration and static pressure over a wide dynamic range. The cantilever UNCD element may be used in combination with a single anode, with measurements made either optically or by capacitance. In another embodiment, the cantilever UNCD element is disposed between two anodes, with DC voltages applied to the two anodes. With a small AC modulated voltage applied to the UNCD cantilever element and because of the symmetry of the applied voltage and the anode-cathode gap distance in the Fowler-Nordheim equation, any change in the anode voltage ratio V1/N2 required to maintain a specified current ratio precisely matches any displacement of the UNCD cantilever element from equilibrium. By measuring changes in the anode voltage ratio required to maintain a specified current ratio, the deflection of the UNCD cantilever can be precisely determined.

Abstract: An accelerometer has a main body in combination with one or more Bragg grating sensors respectively arranged along one or more axes. The main body has a mass that responds to an acceleration, for providing a force having a component in one or more axes. The Bragg grating sensor means responds to the force, and further responds to an optical signal, for providing a Bragg grating sensor signal containing information about the acceleration respectively in one or more axes. The one or more axes may include orthogonal axes such as the X, Y and Z Euclidian axes. In one embodiment, the main body includes a proof mass and a pair of flexure disks, each having an inner ring, an outer ring, and radial splines connecting the inner ring and the outer ring. The proof mass is slidably arranged between the flexure disks. The Bragg grating means has an optical fiber and a Bragg grating sensor arranged therein. A first end of the Bragg grating sensor is fixedly coupled by a first ferrule to the proof mass.