Abstract: A plurality of sensors output information into a distributed acoustic sensing (DAS) system via acousto-mechanical signals. The sensors are coupled to the optic fibre at the centre of the DAS system indirectly, the acousto-mechanical signal being transmitted via an intermediary body, such as the ground or a conduit.

Abstract: The claimed invention provides a blade vibration measuring system comprising a blade, a transmitter, a target with non parallel edges located on the blade shroud and a receiver. The present invention also provides a blade adapted for measuring blade vibration. Furthermore, the claimed invention provides a method for monitoring blade vibration.

Abstract: A photoacoustic measuring apparatus includes a light source, a movable holding unit which holds an object, a light diffusing unit which fixes the distance between the light diffusing unit and the holding unit and diffuses light incident from the light source, and an acoustic wave obtaining unit which obtains an acoustic wave generated from the object by the light emitted via the holding unit and the light diffusing unit.

Abstract: A sample 10 is measured by generating ultrasound at 12, for example by using a laser 22 and spatial light modulator 26. The ultrasound is detected at 16, for example by optical beam deflection techniques. A characteristic of the generation at 12 is swept across a range of values to vary the efficiency of generation of ultrasound. The value of the characteristic, which corresponds with the peak amplitude detected at 16, is identified to provide a measure of the acoustic velocity at the region 12. The method is executed at a plurality of sites 12, 20 to provide a set of spatially resolved measurements of the sample 10. This allows an image of the sample to be created.

Abstract: An integrated transducer device includes an optical transducer and an acoustic transducer integrally joined with the optical transducer. The acoustic transducer includes a membrane responsive to acoustic signals, the membrane being aligned with the optical transducer such that optical signals emitted or received by the optical transducer pass through the membrane. A propagation direction of the acoustic signals emitted or received by the acoustic transducer is collinear with a propagation direction of the optical signals emitted or received by the optical transducer.

Abstract: An acoustic-wave sensor (10) is constructed by a membrane (11) adapted to be displaced by an acoustic wave, a first waveguide (16a) for transmitting light therein, an optical coupling part (15) to which the light transmitted through the first waveguide (16a) is adapted to be optically coupled, and a second waveguide (16b) through which the light coupled from the optical coupling part (15) transmits. When the membrane (11) is displaced by its reception of the acoustic wave, at least one of an optical coupling coefficient between the first waveguide (16a) and the optical resonator (15) and an optical coupling coefficient between the second waveguide (16b) and the optical resonator (15) is changed to output a corresponding optical signal.

Abstract: This disclosure relates in general to a method and system for acoustic monitoring using a fibre optic cable. More specifically, but not by way of limitation, embodiments of the present invention provide for using an optical fiber as a distributed interferometer that may be used to monitor a conduit, wellbore or reservoir. In certain aspects, the distributed interferometric monitoring provides for accurate detection of acoustic occurrences along the fibre optic cable and these acoustic occurrences may include fluid flow in a pipeline or wellbore, processes taking place in a wellbore or pipeline, fracturing, gravel packing, production logging and/or the like.

Abstract: A method 2 of determining the location of deposits in a flowline comprises providing 4 a distributed vibration sensor along the flowline, measuring 6 vibrations along the flowline with the sensor and analysing 8 the measured vibrations to determine the location of any deposits. The vibration measurements are made using a distributed fibre optic sensor provided on the flowline. The measurements are analysed in real time to identify deposit formation and location within the flowline.

Abstract: Forces are applied to a device under test and its mechanical response is measured by a laser vibrometer (50). The forces are applied without making physical contact with the device by producing an acoustical force with an ultrasonic beam (54). One embodiment employs two confocal transducers (56, 58) that produce beams that flood the device. Drive signals modulate the ultrasonic beams to produce the desired forces, and the use on a plurality of ultrasonic beams enable selective excitation of different modes of vibration of the object (7).

Abstract: An optical fiber type vibration meter including a light source, an incident side optical fiber guiding light from the light source, a vibration probe to which a guided light is made incident, an optical receiver photoelectric-converting light modulated by a vibration of a weight and a movable coil arranged in the vibration probe to output the light as an electrical signal, a processor processing the electrical signal to output a state of the vibration as an output voltage value, a velocity pickup converting a velocity of the weight and the movable coil arising from the vibration of the weight and the movable coil into an electrical current, a solenoidal coil generating a magnetic field by the electrical current, and a magnetic field sensor attenuating an amount of light guided to the vibration probe according to an intensity of the magnetic field.

Abstract: Certain embodiments of the invention may include systems and methods for measuring turbine blade vibratory responses. According to an example embodiment of the invention, a method is provided for measuring a vibratory response of a plurality of turbine blades. The method can include mounting an optical probe comprising at least one probe tip optical surface, wherein the at least one probe tip optical surface is substantially parallel to within about +15 or about ?15 degrees with respect to a trailing edge surface of at least one of the plurality of turbine blades, directing light towards a trailing edge surface of at least one of the plurality of turbine blades, receiving reflected light from the at least one of the plurality of turbine blades, and determining relative position of the at least one of the plurality of blades based at least in part on the reflected light.

Abstract: A hydrophone (10) for immersion in a liquid body defining a pressure is disclosed The hydrophone (10) includes a sensor (11) for providing an electrical signal indicative of the pressure; and a transducer (12) electrically connected to the sensor (11). The transducer (12) acts upon a fiber optic cable (15) so as to convert the electrical signal into a corresponding optical output signal for transmission within the fiber optic cable (15). The liquid body defines a depth-dependent static pressure and a dynamic pressure and the sensor (11) provides an electrical signal having a first component indicative of the static pressure and a second component indicative of the dynamic pressure. A filter (16) is electrically connected to the sensor (11) so as to receive (the electrical signal, filter out the first component, and output to the transducer (12) a uttered electrical signal indicative of substantially only the second component.

Abstract: An electronic scale having a measuring sensor (1 . . . 16), a digital signal processing unit (18), a digital display (19), a bubble level (20), which includes a container (21) that is partially filled with a liquid (22) while forming a gas bubble (23), and circuit component or program routine in the digital signal processing unit (18) for detecting a displacement of the gas bubble (23). An additional circuit component or program routine detects the diameter of the gas bubble (23). The diameter of the gas bubble changes due to vertical vibrations of the scale. The signal from the measuring sensor (1 . . . 16) falsified by vibrations can thus be corrected by the digital signal processing unit (18) by calculation, making use of the diameter signal.

Abstract: Apparatus and method for non-contact ultrasonic detection of features on or within the walls of hollow pipes are described. An air-coupled, high-power ultrasonic transducer for generating guided waves in the pipe wall, and a high-sensitivity, air-coupled transducer for detecting these waves, are disposed at a distance apart and at chosen angle with respect to the surface of the pipe, either inside of or outside of the pipe. Measurements may be made in reflection or transmission modes depending on the relative position of the transducers and the pipe. Data are taken by sweeping the frequency of the incident ultrasonic waves, using a tracking narrow-band filter to reduce detected noise, and transforming the frequency domain data into the time domain using fast Fourier transformation, if required.

Abstract: An alignment device with one or two optoelectronic transmitting and/or receiving units and an evaluation unit. At least one optoelectronic transmitting and/or receiving unit contains an inclinometer. Furthermore, the transmitting and/or receiving unit is connected to a vibration sensor which can be the inclinometer. Both the result of the alignment process and also the result of the vibration measurement are communicated to the user as an easily understandable characteristic on a display of the evaluation unit. For vibration measurement at a non-rotating part of a machine, an accelerometer/inclinometer sensor may be used for measuring acceleration forces resulting from machine vibrations to be measured and for measuring gravity and an electronic evaluation unit determining the orientation of the sensor with regard to gravity from a stationary component of the sensor output and determining sensor orientation from evaluation of non-stationary components of sensor output.

Abstract: A sensor arrangement for detecting objects, includes an ultrasonic sensor and an optical sensor integrated into the ultrasonic sensor.

Abstract: A passive, remote sensor including an optical subsystem for receiving electromagnetic radiation scattered off a surface. A detector is responsive to electromagnetic radiation received by the optical subsystem and generates a composite signal comprising a DC current component and an AC current component. A filter extracts the DC current component from the composite signal. A light emitting device is driven by the DC current component. A detector is responsive to the light emitting device and is connected to the first detector to subtract at least a portion of the DC component from the composite signal producing a modified signal. An amplifier is responsive to the modified signal detects vibrations of the surface to be detected.

Abstract: A device for interferometric vibration measurement on an object (8), having a radiation source (1) for generating an original beam, a first beam splitter for dividing the original beam into a measuring beam and a reference beam (4, 5), a detector (10) and a focusing device (9). The device is implemented in such a way that the measuring beam at least partly reflected by the object and the reference beam are superimposed on a detection area of the detector, and the focusing device is arranged in the beam path of the measuring beam for focusing the measuring beam onto a measuring point (7) on the object. It is important that, by using the device, a measuring beam having a wavelength greater than 1100 nm can be generated and that the device additionally has an image unit (12) for two-dimensional imaging of at least a sub-region of the object surrounding the measuring point.

Abstract: An electronic scale having a measuring sensor (1 . . . 16), a digital signal processing unit (18), a digital display (19) and an inclinometer (40). The inclinometer derives a signal for the tilt of the scale from the difference of at least two signals. The digital signal processing unit (18) is provided with an additional circuit component or program routine that adds the two signals and, by way of this cumulative signal, corrects the vibration-distorted signal of the measuring sensor (1 . . . 16). A plurality of inclinometers enables the simultaneous detection of momentary gravitational acceleration. For example, in an electric bubble level, the gas bubble moves out of place when tilted and the diameter of the gas bubble changes when the gravitational acceleration changes. The scale thus provides an additional signal for correcting the influence of disturbances with minimum complexity.

Abstract: Device for measuring the line of sight jitter of an optical instrument mounted on an optical platform, includes: an optical measurement path primarily common with the observation path of the optical instrument, a light measurement source arranged essentially at one end of the optical observation path, a detector for measuring the optical beam coming from the light measurement source, arranged such that this beam has passed through the optical observation path at least once, at least one collimation mirror designed for the reflection of the optical beam, arranged essentially on the optical observation path, essentially at the other end of the optical observation path, relative to the light measurement source, whereby this mirror is isolated by at least one passive isolator of lateral vibrations (i.e., inducing a rotation of the perpendicular line of the mirror) generated by the optical platform in a predetermined frequency range.

Abstract: An acoustic sensor includes at least one structure including at least one photonic crystal slab and an optical fiber optically coupled to the at least one photonic crystal slab, and having at least one optical resonance with a resonance frequency and a resonance lineshape. The acoustic sensor further includes a housing mechanically coupled to the at least one structure. At least one of the resonance frequency and the resonance lineshape is responsive to acoustic waves incident upon the housing.

Abstract: In one aspect, the present invention is directed to an earthquake detection and alarming apparatus, comprising: a transparent object (46) having a concave surface on the top thereof; a rollable object (34) placed on the concave surface; an apiary of light projectors (30) placed above the concave surface; an apiary of light receivers (38) correspondingly to the apiary of light projectors, the apiary of light receivers being placed below the concave surface; and circuitry for determining: (a) vibrating frequency and amplitude of the rollable object with reference to the concave surface from sensing of the receivers (38); and (b) deducing therefrom the arrival of primary waves.

Abstract: Disclosed is a method for characterizing a sample having a structure disposed on or within the sample, comprising the steps of applying a first pulse of light to a surface of the sample for creating a propagating strain pulse in the sample, applying a second pulse of light to the surface so that the second pulse of light interacts with the propagating strain pulse in the sample, sensing from a reflection of the second pulse a change in optical response of the sample, and relating a time of occurrence of the change in optical response to at least one dimension of the structure.

Abstract: A system, program product, and method to perform automated three-dimensional image registration of a part within an inspection cell, are provided. The system can include a laser-ultrasound inspection device having a scanning head to generate ultrasonic surface displacements in a part, an inspection laser, and an interferometer to collect phase modulated light reflected by the part. The system can also include a part position locator positioned to measure a distance between points on a surface of the part and a scanning laser reference location. The system can also include a database containing computer-aided design models for each part of interest, and a model of the inspection cell. The system can further include a laser ultrasound inspection computer communication with the laser-ultrasound detection device and the part position locator, and laser ultrasound inspection program product adapted to perform automated three-dimensional image registration of the part.

Abstract: Disclosed is a method for characterizing a sample having a structure disposed on or within the sample, comprising the steps of applying a first pulse of light to a surface of the sample for creating a propagating strain pulse in the sample, applying a second pulse of light to the surface so that the second pulse of light interacts with the propagating strain pulse in the sample, sensing from a reflection of the second pulse a change in optical response of the sample, and relating a time of occurrence of the change in optical response to at least one dimension of the structure.

Abstract: An optical fiber vibration sensor includes a light source, an optical receiver, an optical dividing/coupling part, a signal processing unit, and a fiber loop part made of an optical fiber. A part of an optical fiber composing the fiber loop part is installed outside a housing of a main body of the optical fiber vibration sensor and another part of the optical fiber composing the fiber loop part is installed outside the housing as a vibration detecting optical fiber.

Abstract: An apparatus and a method that achieve physical separation of sound sources by pointing directly a beam of coherent electromagnetic waves (i.e. laser). Analyzing the physical properties of a beam reflected from the vibrations generating sound source enable the reconstruction of the sound signal generated by the sound source, eliminating the noise component added to the original sound signal. In addition, the use of multiple electromagnetic waves beams or a beam that rapidly skips from one sound source to another allows the physical separation of these sound sources. Aiming each beam to a different sound source ensures the independence of the sound signals sources and therefore provides full sources separation.

Abstract: A microphone having an optical component for converting the sound-induced motion of the diaphragm into an electronic signal using a diffraction grating. The microphone with inter-digitated fingers is fabricated on a silicon substrate using a combination of surface and bulk micromachining techniques. A 1 mm×2 mm microphone diaphragm, made of polysilicon, has stiffeners and hinge supports to ensure that it responds like a rigid body on flexible hinges. The diaphragm is designed to respond to pressure gradients, giving it a first order directional response to incident sound. This mechanical structure is integrated with a compact optoelectronic readout system that displays results based on optical interferometry.

Abstract: An ultrasonic pressure sensor and a method of detecting ultrasonic pressure. In one embodiment, the ultrasonic pressure sensor includes: (1) an interferometer having a reference arm and a signal arm that includes a probing fiber, the probing fiber having a reflective coating at a distal end thereof and configured to couple to ultrasonic waves proximate the distal end, the interferometer configured to receive laser light and produce two output beams based on the ultrasonic waves and (2) a photodetector coupled to the interferometer and configured to generate electronic signals based on the two output beams.

Abstract: An acoustic sensor includes at least one photonic crystal structure having at least one optical resonance with a resonance frequency and a resonance lineshape. The acoustic sensor further includes a housing mechanically coupled to the at least one photonic crystal structure. At least one of the resonance frequency and the resonance lineshape is responsive to acoustic waves incident upon the housing.

Abstract: Apparatus, systems and methods are provided for production and integration of compact illumination schemes. More particularly, disclosed embodiments relate to apparatus/systems and methods for production of highly compact illumination schemes, whereby photoacoustic waves are induced in a target sample. Additionally, the disclosed apparatus/systems and methods are effective to produce compact and portable integrated transducer-illumination arrays. Apparatus disclosed generally include at least one lighting source and a beamsplitting assembly. Systems disclosed generally include one or more apparatus for the production of compact lighting schemes, an ultrasonic transducer assembly and means for coupling the one or more apparatus and US transducer assembly with a target sample.

Abstract: A micro-acoustic radiation detecting apparatus and method are provided herein.

Abstract: Disclosed herein is a method for measuring the vibration of a mirror in a vehicle.

Abstract: A multi-function sensor is disclosed which provides a reliable and simple device for accurately measuring and/or monitoring the ambient conditions within a container or the like, such as the level of a fluid, the turbidity of a fluid, the temperature of a fluid or surrounding environment and the ambient pressure. The sensor incorporates a fluid level sensor module, a turbidity sensor module, a temperature sensor module and a pressure sensor module. The fluid level sensor module utilizes a plurality of thermocouple junctions grouped in pairs with the pairs being spaced along a line extending generally in the direction in which the liquid level may vary. The thermocouple junctions are connected in series and produce a signal indicative of the level of liquid along the sensor. A turbidity sensor module is also integrally included on the multi-function sensor. Additionally, temperature and pressure sensor modules may also be incorporated in the multi-function sensor.

Abstract: An apparatus and a method that achieve physical separation of sound sources by pointing directly a beam of coherent electromagnetic waves (i.e. laser). Analyzing the physical properties of a beam reflected from the vibrations generating sound source enable the reconstruction of the sound signal generated by the sound source, eliminating the noise component added to the original sound signal. In addition, the use of multiple electromagnetic waves beams or a beam that rapidly skips from one sound source to another allows the physical separation of these sound sources. Aiming each beam to a different sound source ensures the independence of the sound signals sources and therefore provides full sources separation.

Abstract: Method and apparatus for noise reduction in ultrasound detection with the steps of: an optical interferometer having a reference arm and a signal arm that includes a polarization-maintaining probing fiber having a reflective coating at a distal end, a way to couple the probing fiber to ultrasound, a way to generate two output beams from the interferometer, a device to modulate the polarization state of the light in the probing fiber, and a detection mechanism responsive to the ultrasonic signals at the distal tip of the probing fiber.

Abstract: A gyroscope sensor includes a gyro disk. A first light source is configured to provide a first light beam adjacent to a first edge of the gyro disk. A first light receiver is configured to receive the first light beam for sensing a vibration at a first direction of the gyro disk.

Abstract: In a schlieren optical system, a laser beam is passed through the jet flow and the ambient around the jet flow, and a high speed sampling is performed using a high speed photo sensor while displacing measurement points. The value obtained by sampling represents a result of the optical path caused curved by a density gradient generated in an arc-shape from the center of the jet flow. The value is subjected to a high speed discrete Fourier transform and decomposed into frequency components which constitute the noise. Thereafter, Abel inversion is performed on data belonging to a particular frequency to obtain a density gradient in the radial direction from the center of the jet flow. The obtained density gradient is visualized in a graph display, so that the position of the sound source and the state of the jet flow can be accurately grasped.

Abstract: Micro-opto-mechanical chemical sensors and methods for simultaneously detecting and discriminating between a variety of vapor-phase analytes. One embodiment of the sensor is a photonic microharp chemical sensor with an array of closely spaced microbridges, each differing slightly in length and coated with a different sorbent polymer. The microbridges can be excited photothermally, and the microbridges can be optically interrogated using microcavity interferometry. Other actuation methods include piezoelectric, piezoresistive, electrothermal, and magnetic. Other read-out techniques include using a lever arm and other interferometric techniques.

Abstract: All-optical photoacoustic spectrometer sensing systems (PASS system) and methods include all the hardware needed to analyze the presence of a large variety of materials (solid, liquid and gas). Some of the all-optical PASS systems require only two optical-fibers to communicate with the opto-electronic power and readout systems that exist outside of the material environment. Methods for improving the signal-to-noise are provided and enable mirco-scale systems and methods for operating such systems.

Abstract: An optical sound detection system including: a laser source to generate a laser beam; an optical fiber; an optical sensor aligned to detect a detected portion of a diffraction pattern formed by the laser light emitted from the output coupling port of the optical fiber; and a signal processor to process the signal produced by the optical sensor. The optical fiber includes: a core that includes a photoelastically active material; an input coupling port optically coupled to the laser source to couple the laser beam into the core of the optical fiber; and an output coupling port from which the laser light is emitted after propagating through the core. The optical sensor is adapted to produce a signal corresponding to the detected portion of the diffraction pattern.

Abstract: A method of determining a contact point of a laser beam on an edge of a body and a system for performing the same, in which the method includes a) moving the laser beam relative to the edge in a spatial direction until the laser beam touches the edge, in which the spatial direction is at a right angle relative to an axis of the laser beam and in which the edge is formed at an opening, b) measuring acoustic oscillations produced photoacoustically during the movement of the laser beam, and c) determining the laser beam point of contact with the edge based on the measured acoustic oscillations.

Abstract: Systems and Methods are disclosed for the detection and imaging of ultrasonic energy. Embodiments of the invention utilize an array of ultrasonic sensors where data from each of the sensors are processed by RMS-to-DC conversion. In addition, embodiments of the invention output a contour map based on detected ultrasonic energy and blend at least one feature of the contour map with a feature of a visible image so that a blended image can be displayed to an operator. Furthermore, embodiments of the invention provide a system and method for repositioning an array of ultrasonic sensors with respect to target area or Unit Under Test (UUT) to facilitate a thorough and repeatable test.

Abstract: A biological information processing apparatus includes the following elements. A light source irradiates biological tissue with light. A transducer functions as an ultrasonic wave transmitting unit that applies an ultrasonic wave to a local region in the biological tissue. A photodetector detects modulated light obtained by modulating the light from the light source with the ultrasonic wave in the local region. The transducer also functions as an acoustic wave detecting unit that detects an acoustic wave emitted from the local region at a time when the local region absorbs the light from the light source. An absorption characteristic in the local region is calculated using an acoustic signal, serving as an output of the acoustic wave detecting unit, on the basis of a light intensity in the local region calculated based on a modulation signal, serving as an output of the photodetector.

Abstract: A measurement apparatus includes a DOT measurement unit, an AOT measurement unit, and a controller configured to calculate at least one of an absorption characteristic and a scattering characteristic of a test region set in an test object by utilizing one of the DOT measurement unit and the AOT measurement unit, which one has a smaller measurement size.

Abstract: A sensor and a method for sensing a change in mass of a reflective microbeam in a sensor, the sensor having a reflective layer disposed on a substrate and spaced apart from the reflective microbeam. The microbeam receives amplitude modulated laser energy at a first wavelength and is photothermally excited into resonance at the frequency of amplitude modulation, the reflective microbridge and the reflective layer receive optical energy at a second wavelength and reflect the optical energy toward a receiver. A change in reflectivity of the microbeam at different frequencies is determined. A change in reflectivity indicates a change in resonant frequency of the microbeam. Mass of the microbeam changes when a chemoselective material on the microbeam sorbs a target chemical.

Abstract: An ultrasonic probe for optical detection of ultrasonic waves includes a membrane integrated into the probe for contact with a body, the membrane being excited to vibration by reflected ultrasonic waves, leading to a change in optical path length of a beam of light directed at the membrane, which change is determined interferometrically.

Abstract: A micro-electrical mechanical oscillator has a resonant frequency of oscillation that is varied by application of heat. The resonant frequency is varied at a frequency different from the resonant frequency of the oscillator to amplify oscillations. In one embodiment, the oscillator is disc of material supported by a pillar of much smaller diameter than the disc. The periphery of the disc is heated by a laser to provide a time varying shift of the resonant frequency (or equivalently the stiffness) of the disc. Feedback from movement of the disc is used to modulate the intensity of the laser, and thus the stiffness of the disc to provide parametric amplification of sensed vibrations, using heating as a pump. Various other shapes of micro-electrical mechanical oscillators are used in other embodiment, including an array of such oscillators on a substrate, each having different resonant frequencies.

Abstract: A system includes a liquid cooling medium, a cooling plate having opposite first and second sides and at least one internal passage in which the liquid cooling medium flows, first and second lasers located adjacent to one another and positioned relative to the first side of the cooling plate, and a first Peltier device operably connected between the first side of the cooling plate and the first and second lasers for transferring thermal energy to the liquid cooling medium in the cooling plate.

Abstract: A fiberoptic multi-parameter sensing system for monitoring turbomachinery system shaft static and dynamic torques, vibration modes and associated operation status includes a multi-furcated fiber bundle based optical splitter configured to transmit light to a surface of at least one turbomachinery system shaft through a plurality of optical fiber bundles disposed at a plurality of locations in proximity to the surface of the at least one shaft, in which the plurality of locations together are arranged in a substantially axial direction between the ends of the at least one shaft.