Optech Ventures, LLC

Other

Hrl Laboratories, LLC

Hughes Electronics Corporation

Boston University

Intelligent Optical Systems, Inc.

Lasson Technologies, Inc.

Iphoton Solutions, LLC

Marvin E Klein

David M Pepper

Gilmore Joseph Dunning

Bruno F Pouet

David D Nolte

Gerald David Bacher

Todd W Murray

Thomas E Drake

Marc Dubois

John E Kulesza

Jerome Eichenberger

G David Bacher

Meng P Chiao

Todd Sienicki

Kenneth Bacher

Jerome Eichenbergeer

Andrew D W McKie

Konstantin Shcherbin

Frank Jyh-Herng Shih

John Anthony Coy

A system, probe and method accurately measure the strain or extension of a fastener that occurs as a nut on the fastener is tightened and the fastener is put under load. The measurement technique is based on measurement of the time for an ultrasonic wave generated on one end of the fastener to travel a round trip through the fastener. As the fastener is tightened, the applied stress causes an associated increase in length. This length can be determined from a measurement of the increase in transit time. In various embodiments, the disclosed device and method uses laser ultrasonic testing (LUT), in which a pulsed laser generates the ultrasonic wave and a type of laser vibrometer detects the wave when it returns to the position of generation following a combination of longitudinal and shear wave reflections, which result in a higher magnitude and more easily and precisely measurable reflected signal peak than a signal peak associated with a signal directly reflected against the opposite end of the fastener.

Laser ultrasonic fastener load measurement probe

In the present disclosure, embodiments including a system, probe and method are disclosed for accurately measuring the strain or extension of a fastener that occurs as the nut on the fastener is tightened and the fastener is put under load. The measurement technique is based on measurement of the time for an ultrasonic wave generated on one end of the fastener to travel a round trip through the fastener. As the fastener is tightened, the applied stress causes an associated increase in length. This length can be determined from a measurement of the increase in transit time. In various embodiments, the disclosed device and method uses laser ultrasonic testing (LUT), in which a pulsed laser generates the ultrasonic wave and a type of laser vibrometer detects the wave when it returns to the position of generation following a combination of longitudinal and shear wave reflections.

System, probe and method for measurement of fastener loading

In the present disclosure, embodiments including a system, device and methods are disclosed for accurately measuring the strain or extension of a fastener that occurs as the nut on the fastener is tightened and the fastener is put under load. The measurement technique is based on measurement of the time for an ultrasonic wave generated on one end of the fastener to travel a round trip through the fastener. As the fastener is tightened, the applied stress causes an associated increase in length. This length can be determined from a measurement of the increase in transit time. In various embodiments, the disclosed device and method uses laser ultrasonic testing (LUT), in which a pulsed laser generates the ultrasonic wave and a type of laser vibrometer detects the wave when it returns to the position of generation following a combination of longitudinal wave reflections and a mode conversion to a shear wave.

System, device and method for measurement of fastener loading

A device detects underfill voids and solder ball defects via laser generation and laser detection of an ultrasonic wave at the top surface of flip chips. High resolution is provided by using small laser spot sizes and closely-spaced laser beams of wavelengths that are absorbed near the surface of the semiconductor. Improved spatial resolution and rejection of unwanted scattered waves can be attained by limiting the time frame of the ultrasonic waveform to the time required for the first longitudinal wave reflection from the bottom of the flip chip. The laser beam spacing can be reduced by using probe and detection beams of different wavelengths. Resolution of less than 100 &#x3bc;m features was demonstrated for silicon flip chips.

Device for laser-ultrasonic detection of flip chip attachment defects

A laser ultrasonic measurement system includes a first and a second laser source configured to generate a first and a second laser beam, respectively. A movable mechanical link is arranged to transmit the first laser beam. The movable mechanical link is formed by a plurality of rigid sections interconnected by rotating joints. A robot is configured to support and control the movement of at least a section of the mechanical link to transmit the first laser beam to an object. An optical scanner is positioned proximate to the mechanical link. The optical scanner is configured to direct the first and second laser beams onto the object. An interferometer is optically coupled to the optical scanner. The interferometer is configured to receive reflected light from the object and in response generate an electrical signal. The first laser source is kinematically mounted in a housing assembly.

Laser ultrasonic measurement system with movable beam delivery

Faults, dimensions and other characteristics of a material or structure are sensed by a coherent beam's reflection from the material when probed with ultrasonic waves or when vibrating at high frequencies. The reflected beam acquires a dynamic phase change substantially different from its original phase and from the phase of a reference beam split from the common source beam. The reflected beam and the reference beam are superimposed by diffraction in an adaptive holographic beam-splitter, and the superimposed beams are detected by a photodetector capable of detecting small phase changes from ultrasonic surface displacements or perturbations. An apparatus and method are disclosed defining an improved crystal homodyne interferometer with an energy source coupled to the crystal and operative to maintain the crystal in a condition for emptying unwanted traps in the crystal.

Optical homodyne interferometer

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

Underfill voids and solder ball defects are detected via laser generation and laser detection of an ultrasonic wave at the top surface of flip chips. High resolution is provided by using small laser spot sizes and closely-spaced laser beams of wavelengths that are absorbed near the surface of the semiconductor. Alternatively, the generation laser beam may be absorbed in the bulk of the semiconductor. Improved spatial resolution and rejection of unwanted scattered waves can be attained by limiting the time frame of the ultrasonic waveform to the time required for the first longitudinal wave reflection from the bottom of the flip chip. The laser beam spacing can be reduced by using overlapping probe and detection beams of different wavelengths. Resolution of less than 100 &#x3bc;m features was demonstrated for silicon flip chips.

Laser-ultrasonic detection of flip chip attachment defects

Subsurface defects in a processed metal are detected by a laser-ultrasonic method involving generation of a surface acoustic wave at one location on the processed metal surface, and detection of a scattered acoustic wave at another location on the processed metal surface. The method can be used in-line to provide real time monitoring of laser cladding and other metal processing operations.

Laser-ultrasonic detection of subsurface defects in processed metals

A composition for the treatment of skin comprises a carboxylated, acidic amino acid obtained by acidifying an acidic amino acid with a carboxylic acid. The resultant material, which is also referred to as a tricarboxylic acid or an amino fruit acid, has significant benefit for the treatment of a number of skin conditions. In addition, the composition of the present invention is very noncaustic to skin, even when employed at a pH as low as 0.5. Also disclosed herein are therapeutic methods and compositions which employ the carboxylated acidic amino acids.

Composition for treatment of skin and method for stabilizing the composition

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

A photo-EMF sensor and a method of making same has a substrate with a semiconducting layer; a plurality of sensing regions in the layer, each sensing region including (i) a pair of electrodes disposed in, on or above the layer and (ii) an active region in the layer disposed adjacent said pair of electrodes; and a plurality of inactive regions in said the arranged between adjacent sensing regions. The inactive regions and the sensing regions are dosed with a desensitizing agent, the inactive regions receiving a relatively higher dose of the desensitizing agent and the sensing regions receiving a relatively lower dose of the desensitizing agent. The active layer is preferably placed in a monolithic Fabry-Perot cavity to enhance the optical efficiency and performance of the sensor.

Enhanced photo-EMF sensor with high bandwidth and large field of view

A composition for the treatment of skin consists essentially of a carboxylated, acidic amino acid obtained by acidifying an acidic amino acid with a carboxylic acid. The resultant material, which is also referred to as a tricarboxylic acid or an amino fruit acid, has significant benefit for the treatment of a number of skin conditions. In addition, the composition of the present invention is very noncaustic to skin, even when employed at a pH as low as 0.5. Also disclosed herein are therapeutic methods and compositions which employ the carboxylated acidic amino acids.

Amino fruit acid composition and method for the treatment of skin

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.

Growing community of inventors

Farmington Hills, MI, United States of America

Marvin E Klein