Bossa Nova Technologies, LLC

Hrl Laboratories, LLC

Lasson Technologies, Inc.

Other

Kawasaki Steel Corporation

Bruno F Pouet

Marvin E Klein

David M Pepper

Gerald David Bacher

Gilmore Joseph Dunning

Marvin B Klein

Jerome Eichenberger

Nicolas Lechocinski

Sebastien Breugnot

Andrew D W McKie

Frank Jyh-Herng Shih

Makoto Okuno

Hideo Sato

A method and apparatus for a photoinduced electromotive force sensor. The sensor has an active substrate formed of a semi-insulating photoconductor with sufficient carrier trap density to form an effective charge grating and pairs of electrodes disposed on the active substrate, where the sensor is configured to reduce the photovoltaic effect caused by the incident light in the vicinity of the electrodes. The shape or composition of the electrodes may be selected to reduce the photovoltaic effect or the electrodes may be disposed on the substrate to average out the photovoltaic effect arising from each one of the electrodes.

Method and apparatus for reduction of non-adaptive signals in photo-EMF sensors

Methods and apparatus to determine the orientation of randomly arranged birefringent fibers are disclosed. One method comprises emitting light, creating Npolarization states of the emitted light, illuminating the birefringent fibers with the emitted light so polarized, thereby generating IRinternal reflection components of the light in the birefringent fibers, observing the light from the illuminated birefringent fibers, creating Opolarization states of the observed light, forming Iimages of the observed polarized light, each image comprising an information (N, O, IR), wherein i=1, 2, . . . , n and n&#x2267;3, separating the i-th internal reflection component from the i-th image, and calculating an angle of a neutral axis of the birefringent fibers using the IRinternal reflection components.

Birefringent fibers orientation measurement

A multi-channel laser interferometric method and apparatus are provided for optically measuring transient motion from a surface (). A laser beam () is generated and then divided into first and second beams having respective intensities representing minor and major fraction of the predetermined laser intensity. The reference beam () illuminates the surface () at which deformation is expected. The light back-scattered by the surface is collected by a single aperture lens () and then made to interfere with the probe beam () which has been expanded (), onto a two-dimensional array of detectors (). Each signal () corresponding to each detector of the array is converted individually to an electrical signal, each electrical signal is amplified and processed (), and the plurality of processed signals () is then averaged in an electrical summing means ().

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 frequency shift between the reference beam and the scattered object beam, wherein the frequency shift is smaller than the ultrasonic frequency, detecting the interference between the scattered object beam and the frequency shifted 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.

Interferometric method and apparatus for linear detection of motion from a surface

A laser interferometric apparatus for measuring a displacement of an object is disclosed, the apparatus comprising a laser source for producing a laser beam having a given intensity, a beam splitter for dividing the laser beam into a reference beam and an object beam to be directed to the object, thereby producing a scattered object beam being modulated according to the displacement of the object, interference means adapted to provide at least two electrical interference signals from the scattered object beam and the reference beam, the at least two electrical interference signals each comprising a wanted signal component indicative of the object displacement and an intensity noise component, and processing means for subtracting the at least two electrical interference signals, thereby generating an output signal, the output signal comprising substantially the wanted signal component alone, wherein the intensity noise is substantially rejected.

Laser intensity noise rejection for interferometric apparatus

Dynamic vibration monitoring of a cutting tool or workpiece is provided by propagating an ultrasonic carrier beam in a stream of fluid flowing from a probe chamber, which includes a transducer, to the cutting tool or workpiece target area. The modulated ultrasonic beam reflected from the target is detected via a transducer in the chamber, and is demodulated to provide measurements of vibrational surface displacement and velocity. The method is insensitive to the target surface roughness and can be used for dynamic characterization prior to machining, and for monitoring during the machining operation. The device is inexpensive and robust to the machining environment, and can be applied to small cutting tools.

Method and device for ultrasonic vibration detection during high-performance machining

Longitudinal and shear ultrasonic waves are generated inside a material by irradiating a laser beam onto a first surface, e.g., incident surface, of the material. An ultrasonic longitudinal wave and a mode converted wave reflected by a second surface, e.g., a bottom surface, of the material are detected, and times of flight of the ultrasonic longitudinal wave and the mode converted wave are measured. A thickness of the material is measured based on the times of flight and a correlation, obtained in advance, between longitudinal and shear wave velocities of the material and temperature of the material.

Material thickness measurement method and apparatus

A laser-based technique to determine glass thickness employs a pulsed laser to induce an ultrasonic wave between the surfaces of a region of glass, causing the surfaces to move in and out at a characteristic frequency. The surface motion is monitored to determine the characteristic frequency, which is proportional to the thickness of the glass in the region of the ultrasonic wave. The pulsed laser produces a short duration pulse that illuminates a surface of the glass, which is absorbed within the glass to cause a rapid thermal expansion that generates the ultrasonic wave. The surface motion induced by the ultrasonic wave is preferably detected with a laser interferometer system, the output of which is analyzed to determine the surface motion's characteristic frequency.

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Culver City, CA, United States of America

Bruno F Pouet