Class / Patent application number | Description | Number of patent applications / Date published |
356502000 | Surface displacement due to acoustic wave propagation) | 14 |
20080291465 | NON-DESTRUCTIVE INSPECTION USING LASER-ULTRASOUND AND INFRARED THERMOGRAPHY - An inspection system is provided to examine internal structures of a target material. This inspection system includes a generation laser, an ultrasonic detection system, a thermal imaging system, and a processor/control module. The generation laser produces a pulsed laser beam that is operable to induce ultrasonic displacements and thermal transients at the target material. The ultrasonic detection system detects ultrasonic surface displacements at the target material. The thermal imaging system detects thermal transients at the target material. The processor analyzes both detected ultrasonic displacements and thermal imagery of the target material to yield information about the target material's internal structure. | 11-27-2008 |
20080291466 | METHOD AND DEVICE FOR NON-CONTACT OSCILLATION MEASUREMENTS - A method and a device to measure oscillations of an object. The method includes the processing steps: Determining at least one point of the object to be measured, moving at least one laser interferometer fastened on a carrier into a measuring position for measuring the measuring point on the object, emitting at least one measuring beam of the laser interferometer to at least one measuring point on the object, detecting the measuring beam reflected by the object, determining the oscillation data from the emitted and reflected measuring beam, allocating the oscillation data to the measuring point, as well as evaluating the oscillation data and displaying the oscillation data of the measuring point, with at least one comparison of a position of the laser interferometer being performed using at least one position of a known freely predetermined point on the object and a transformation rule being prepared to determine the position of the laser interferometer in reference to the object for arbitrary measuring positions based on the comparison. The device for measuring oscillations includes at least one laser interferometer with a measuring beam emitter and a detector for the measuring beam reflected by the object, a movably arranged carrier on which the laser interferometer is mounted, a control unit to control the carrier arranged in a mobile fashion, as well as a data collection and processing device to record and process oscillation data cooperating with the emitter and detector and with the carrier. A device is provided to calculate measuring positions of the laser interferometer, with the calculation of the measuring positions comprising a direct or indirect comparison of the position of a known point on the object to the position of the laser interferometer. | 11-27-2008 |
20080316498 | APPARATUS AND METHOD FOR TWO WAVE MIXING (TWM) BASED ULTRASONIC LASER TESTING - A system and method for detecting ultrasonic surface displacements at a remote target are disclosed, one embodiment of the system comprising: a first laser to generate a first laser beam. The first laser beam produces ultrasonic surface displacements on a surface of the remote target. A second laser generates a second laser beam operable to detect the ultrasonic surface displacements on the surface of the remote target and to provide a reference beam to an interferometer. The second laser beam is split, at a beam-splitter, into a pump beam and a probe beam. The pump beam is amplified by a first amplifier and the probe beam is amplified by a second amplifier. The pump beam is then provided to the interferometer as a reference beam and the probe beam is directed to the target to detect the ultrasonic surface displacements. The first and second amplifiers can be controlled independently of one another to control their respective laser beam's power. Collection optics collect phase modulated light from the probe beam either reflected or scattered by the remote target, which can be optionally optically processed to increase the light intensity. The interferometer is a TWM interferometer that receives and processes the phase modulated light and generates at least one output signal based on the phase-modulated light and the amplified reference laser beam. | 12-25-2008 |
20090027688 | Multi-channel laser interferometric method and apparatus for detection of ultrasonic motion from a surface - A multi-channel laser interferometric method and apparatus are provided for optically measuring transient motion from a surface ( | 01-29-2009 |
20090147267 | Laser doppler vibrometer employing active frequency feedback - A laser Doppler vibrometer for vibration measurement that employs active feedback to cancel the effect of large vibration excursions at low frequencies, obviating the need to unwrap phase data. The Doppler shift of a reflective vibrating test object is sensed interferometrically and compensated by means of a voltage-controlled oscillator driving an acousto-optic modulator. For frequencies within the servo bandwidth, the feedback signal provides a direct measurement of vibration velocity. For frequencies outside the servo bandwidth, feedback biases the interferometer at a point of maximal sensitivity, thus enabling phase-sensitive measurement of the high-frequency excursions. Using two measurements, one with a low bandwidth and one with a high bandwidth, more than five decades of frequency may be spanned. This approach is of particular interest for the frequently occurring situation where vibration amplitudes at low frequency exceed an optical wavelength, but knowledge of the vibration spectrum at high frequency is also important. | 06-11-2009 |
20090168074 | Method of Assessing Bond Integrity in Bonded Structures - A technique for acoustic detection of a disbond within a bonded structure involves thermal excitation of the surface of the bonded structure to induce a lifting and membrane vibration and is applicable to laminates and coated structures, as well as foam core structures or a honeycomb structures. The technique does not require access to both sides of the bonded structure. A large etendue interferometer is used to provide surface displacement measurement. The surface displacement measurement can be analyzed both by frequency or amplitude to determine existence of a disbond by membrane vibration, and further a thickness of the disbond can be determined using traditional pulse-echo time analysis. The technique may allow detection of stick bonds. | 07-02-2009 |
20090284751 | METHOD AND APPARATUS FOR GENERATING MID-IR LASER FOR ULTRASOUND INSPECTION - A method of ultrasonic testing comprising conditioning a radiation wave from a laser source by efficiently converting the radiation wave's wavelength to a mid-IR wavelength for enhanced ultrasonic testing of a composite. The method includes passing the radiation wave through a first optical frequency converter where the radiation wave is converted into a signal wave and an idler wave, where the idler wave is at a mid-IR wavelength. The method further includes directing the signal and idler waves to a second optical frequency converter where the signal wave wavelength is converted to a mid-IR wavelength which combines with the idler wave to form a generation wave. The generation wave is directed at a composite surface to be tested. | 11-19-2009 |
20090284752 | METHOD AND APPARATUS FOR SPECTROSCOPIC CHARACTERIZATION OF SAMPLES USING A LASER-ULTRASOUND SYSTEM - A method of spectroscopic analysis of a material using a laser ultrasound system. The method includes measuring amplitude displacement of a target surface that has been excited with a generation laser. The amplitude displacements relate to the target's optical absorption properties. Amplitude displacements are generated over a range of laser wavelengths to obtain an optical absorption signature useful to identify the target material characteristics. | 11-19-2009 |
20100128281 | MICROSTRUCTURAL FEATURE AND MATERIAL PROPERTY MONITORING DEVICE FOR METALLIC MATERIAL - A microstructural feature and material property monitoring device for a metallic material that can easily adjust relative position between an irradiation position of laser beams applied to the metallic material to propagate pulsed ultrasonic waves in the metallic material and detection position of a laser interferometer, and therefore can accurately monitor the microstructural feature and material property of the metallic material. The device relatively moves the irradiation position of the laser beams generated by a laser oscillator and the detection position of the laser interferometer. The irradiation position of the laser beams generated from a laser oscillator and the detection position of the laser interferometer are controlled to be aligned with a relative position according to the microstructural feature and material property of the metallic material based on the time from the transmission of the pulsed ultrasonic waves to the detection by the laser interferometer. After the alignment, the microstructural feature and material property of the metallic material is calculated based on the waveform of the pulsed ultrasonic waves generated as an electrical signal by the laser interferometer. | 05-27-2010 |
20120320383 | Enclosed Laser-Ultrasonic Inspection System - A laser ultrasonic inspection system comprises laser sources configured to generate laser beams, an optical scanner configured to direct the laser beams onto an object thereby generating ultrasonic waves in the object and illuminating the object, an interferometer configured to generate an electrical signal in response to the reflected light, and a radiation restricting inspection chamber for housing the object. Another laser ultrasonic inspection system comprises a radiation restricting inspection chamber, laser sources located outside of the inspection chamber, an optical scanner located inside the inspection chamber, a visible laser tracer representative of the orientation of the laser beams; an interferometer, a scanner positioning mechanism, and an object positioning mechanism. A method for inspecting an object comprises the steps of positioning an object inside of an inspection chamber, defining a scanning profile, and directing laser beams onto the object according to the inspection profile. | 12-20-2012 |
20130208284 | MULTI-CHANNEL LASER INTERFEROMETRIC METHOD AND APPARATUS FOR DETECTION OF ULTRASONIC MOTION FROM A SURFACE - An apparatus and a method for detecting surface motion of an object subject to ultrasound are disclosed. The method comprises generating a laser beam, dividing the laser beam into a reference beam and an object beam to be directed onto the surface, thereby producing a scattered object beam, introducing a small-amplitude modulation in the optical path difference between the reference beam and the scattered object beam, detecting the interference between the scattered object beam and the phase modulated reference beam using a plurality of detecting elements to generate a plurality of electrical interference signals, wherein the electrical interference signals each comprise a wanted signal component indicative of the surface motion and a noise signal component, and processing the electrical interference signals to determine the surface motion of the object. | 08-15-2013 |
20140247456 | METHOD FOR PHOTOACOUSTIC TOMOGRAPY - The invention relates to a method for photoacoustic tomography of a sample, deformations on a measurement surface of the sample being measured as a function of location and time, the deformations resulting from the absorption of a pulsed excitation radiation on at least one spectrally addressable target structure in the sample interior while emitting thermomechanical pressure waves in the direction of the measurement surface, and the measured deformations being fed to a reconstruction method for determining the position of the target structure in the sample interior. | 09-04-2014 |
20160025683 | MANAGING A SOUND SYSTEM - For managing a sound system, a method is disclosed that includes identifying a location for measuring sound, directing light from a light emitter to the location, determining a speckle pattern at the location based on data received from an optical interferometer, and adjusting a sound producer based on the determined speckle pattern. | 01-28-2016 |
20160054270 | METHOD AND SYSTEM FOR BURIED LAND MINE DETECTION THROUGH DERIVATIVE ANALYSIS OF LASER INTERFEROMETRY - A method of detecting land mines includes pre-processing a raw laser interferometer image, processing pre-processed image by calculating one or more derivatives having one or more peaks, along vectors extending in at least two different directions, mapping the peaks of said derivatives to create a derivative map, and detecting an anomalous signature in the derivative map. | 02-25-2016 |