Abstract: A sensor comprises an optical modulator that generates a modulation signal, an interferometer that mixes an acoustic signal evoked by a pulsed laser with the modulation signal to down-convert the acoustic signal to lower frequencies, and a photodetector that detects the down-converted signal.

Abstract: The present invention for detecting ultasonic displacements includes a detection laser to generate a first pulsed laser beam to generate the ultrasonic surface displacements on a surface of the target. A seocond pulsed laser beam to detect the ultrasonic surface displacements on a surface of the target. Collection optics to collect phase modulated light from the first pulsed laser beam either reflected or scattered by the target. An interferometer which processes the phase modulated light and generate at least one output signal. A processor that processes the at least one output signal to obtain data representative of the ultrasonic surface displacements at the target.

Abstract: 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.

Abstract: A method and a device to measure oscillations of an object.

Abstract: A method for characterizing one or more properties of a sample using acoustic waveforms is disclosed, and comprises directing a sequence of at least three optical pulses to the sample to generate an acoustic response in the sample at a frequency corresponding to the pulse sequence, varying the timing of one or more of the pulses in the sequence to vary the frequency of the acoustic response in the sample, and measuring the strength of the acoustic response as a function of the varied frequency to determine information about the sample.

Abstract: The present invention provides a method to detect and generate ultrasonic displacements at a remote target for ultrasonic inspection. This method involves generating an ultrasonic wave at a first location on an upper surface of the remote target. This ultrasonic wave is reflected from interior surfaces within the remote target wherein the reflected ultrasonic wave produces ultrasonic displacement at a second location on the upper surface of the remote target. A detection laser beam is generated and directed to the second location on the upper surface of the remote target. Here, the detection laser beam is scattered by the ultrasonic displacements to produce phase-modulated light. This phase-modulated light is collected and processed to obtain data representative of the ultrasonic surface displacements. Further, these ultrasonic displacements, when processed, will yield inspection information associated with the interior of the remote target.

Abstract: Described are a sensor and a method for measuring a vibration of a surface obscured from view. The sensor includes a narrowband source of a terahertz beam, a beamsplitter, a beam combiner and a terahertz detector. The beamsplitter splits the terahertz beam into a sample beam for irradiating the surface and a reference beam. The beam combiner combines the sample beam scattered from the surface and the reference beam. The terahertz detector generates an electrical signal based on a modulation of the power of the combined beams due to the vibrating surface. The electrical signal indicates a characteristic of the surface vibration. Homodyne or heterodyne detection can be utilized. Advantageously, the sensor can see surfaces that are covered, concealed or otherwise obscured behind optically opaque materials, including plastic, cloth, foam, paper and other materials. Thus the sensor has a wide variety of applications where conventional vibrometers are not practical.

Abstract: The invention is directed to a system and method for implementing process control for paint thickness using sonic NDE techniques. The system may, for example, generate ultrasound waves in a test object during the manufacturing process. A detector such as an interferometer may be used to detect the ultrasound waves. An interpreter or analyzer may determine the thickness and or presence of a defect from the waves. Further, the interpreter may associate the thickness measurement and/or defect with a location about an object. Then, a control system may determine and implement an appropriate control action on the process. The control action may also be associated with the location about the object.

Abstract: 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 ?m features was demonstrated for silicon flip chips.

Abstract: In one embodiment, a probe pulse is first stretched into a pulse of longer duration. The probe pulse comprises a plurality of wavelength components in a bandwidth, so that each temporal portion of the converted pulse corresponds to and comprises one of the wavelength components. This converted pulse is supplied to the sample at the time when it is affected by the disturbance of the sample caused by a pump pulse. Changes in characteristics of the sample at the wavelength components of the temporal portions of the converted pulse are then detected after the converted pulse has been modified by the sample. Such changes are then analyzed to derive characteristics of the sample. In another embodiment, a converter passes to a detector radiation from a probe beam that has been modified by the sample during a temporal sequence of time intervals, where the time intervals correspond to displacement in a spatial record.

Abstract: A system and method for laser light amplification provides amplification of a laser light beam emitted from a laser light source as low-amplification seed laser light signal. The low-amplification seed laser light signal is transmitted to an amplification component. The amplification component amplifies the low-amplification seed laser light signal by stimulating emissions of the population inversion provided by a pumping diode to generate an amplified laser light signal. The system and method further directs the amplified laser light signal to an output destination. The destination may be an object undergoing laser ultrasound testing. The amplified laser light may reflect with a modulation characteristic of a sound energy wave about the object. The reflected laser light may be collected by an interferometer and used in the detection and characterization of the sound energy wave.

Abstract: A laser ultrasonic inspection apparatus and method which enables remote sensing of thickness, hardness, temperature and/or internal defect detection is disclosed. A laser generator impinges a workpiece with light for generating a thermo-elastic acoustic reaction in a workpiece. A probe laser impinges the workpiece with an annularly-shaped probe light for interaction with the acoustic signal in the workpiece resulting in a modulated return beam. A photodetector having a sensitive region for detecting an annularly-shaped fringe pattern generated by an interaction of a reference signal and with the modulated return beam at said sensitive region.

Abstract: An acoustic sensor used in underwater applications. The sensor includes a reflective material adhered to a structure, such as an outer submarine hull or any marine vessel hull. A laser interferometer is placed on the side of the structure with the reflective material. The laser interferometer sends a plurality of laser beams, in sequence or all at one time, to a plurality of points across the retro-reflective material. The laser beams reflect back to the interferometer, which captures the reflected beams using receiving optics. The phase modulation of the reflected laser beams is compared to a reference laser beam within the interferometer to obtain the vibration velocity characteristics of the hull surface structure. Since the reflective material is adhered to the structure, the structure vibration is the same as the vibration of the reflective material. From this vibration, the acoustic pressure associated with the structure may be calculated.

Abstract: An optical system provides information about tangential vibration components of a surface at remote location. The optical system includes a light source assembly that emits first and second beams, each having one or more wavelengths and one or two polarizations. The first and second beams are directed to the interrogated surface. A detector system is positioned to detect a third beam formed by at least a portion of the first and second beams being reflected from the interrogated surface. The first, second and third beams having incident and reflection angles relative to the interrogated surface that do not lay in a same plane. The detector system positioned remotely from the interrogated surface, and providing information on a phase change in the third beam relative to the first and second beam. The phase change is indicative of at least one surface vibration vector component of the interrogated surface. The detector system is a 90 degree optical hybrid balanced detector with four photodiodes.

Abstract: This invention relates to a scanning ultrasound detection device using two-wave mixing in photorefractive crystal interferometry. An interferometer with two-wave mixing in photorefractive crystal, and cooperates with a confocal lenses module to perform a scan and inspection of the surface of a target. A rotating unit is used for directing a signal beam for detection to be incident upon different locations of the target. The confocal lens module is used to compensate any changes of reflection path caused by the signal beam having different incident angles. Hence, a reflected signal beam and a reference beam can strike on a photo detector.

Abstract: Diffraction grating based fiber optic interferometric systems for use in optical coherence tomography, wherein sample and reference light beams are formed by a first beam splitter and the sample light beam received from a sample and a reference light beam are combined on a second beam splitter. In one embodiment, the first beam splitter is an approximately 50/50 beam splitter, and the second beam splitter is a non 50/50 beam splitter. More than half of the energy of the sample light beam is directed into the combined beam and less than half of the energy of the reference light beam are directed into the combined beam by the second beam splitter. In another embodiment, the first beam splitter is a non 50/50 beam splitter and the second beam splitter is an approximately 50/50 beam splitter. An optical circulator is provided to enable the sample light beam to bypass the first beam splitter after interaction with a sample.

Abstract: An imaging system includes: an object wavefront source and an optical microscope objective all positioned to direct an object wavefront onto an area of a vibrating subject surface encompassed by a field of view of the microscope objective, and to direct a modulated object wavefront reflected from the encompassed surface area through a photorefractive material; and a reference wavefront source and at least one phase modulator all positioned to direct a reference wavefront through the phase modulator and to direct a modulated reference wavefront from the phase modulator through the photorefractive material to interfere with the modulated object wavefront. The photorefractive material has a composition and a position such that interference of the modulated object wavefront and modulated reference wavefront occurs within the photorefractive material, providing a full-field, real-time image signal of the encompassed surface area.

Abstract: A method and device for measuring the wall thickness of a pipe in a pipe-rolling mill wherein a Fabry-Pérot interfero-meter has its mirror spacing set by providing an input to a linear activity for one of the mirrors from a controller receiving an input from a photodiode at the output side of the interferometer. A second control circuit regulates the amplification of that photodiode with at least one parameter derived from the rolling system, for example, the input optical signal to the interferometer or a disturbance value representing for example the temperature of the rolled product and obtained through an optical pyrometer. The incoming optical signal may be tapped to another photodiode also with a variable amplification amplifier and both amplifiers may be controlled by a second controller.

Abstract: An apparatus to measure micro-forces includes a cantilever palette with a set of cantilever array blocks. Each cantilever array block includes a set of cantilevers, with each cantilever including a set of cantilever fingers surrounded by a frame with frame fingers. The cantilever fingers and the frame fingers form a diffraction grating. Each cantilever array block is configured to be responsive to a predetermined micro-force, such that cantilevers of the cantilever array block deflect in the presence of the predetermined micro-force, which causes the diffraction grating to diffract light and thereby provide a visual indication of the presence of the predetermined micro-force.

Abstract: An interferometer sensor has a two-dimensional sensor head (1) comprising a polymer film (4) of substantially uniform thickness. An interrogating signal (12) is provided to the sensor head, the interrogation signal extending across the area of the sensor head and being incident normally to the sensor head (1). An optical sensing device (16) is arranged to receive an optical output signal from the sensor head at a location remote from the sensor head. The sensor converts ultrasound signals appearing over a two dimensional surface to an optical signal pattern, using a polymer interferometer sensing film. Spatial discretisation of the ultrasound signal pattern is performed by an optical sensing device. Such optical devices can be arranged having sufficiently high resolution to enable beam-steering imaging to be performed, including imaging outside the footprint of the sensor head.

Abstract: Methods for measuring strains in biological and other samples include illuminating a specimen with substantially collimated laser flux. An electro-acoustic transducer is activated to generate acoustic waves in the specimen, including a surface wave component such as a Rayleigh wave. A series of laser speckle patterns produced by a laser flux scattered or reflected by the specimen is recorded and speckle pattern shifts are calculated based on the recorded speckle patterns. Phase shifts produced by acoustic wave propagation in the specimen are used to identify specimen regions associated with irregularities such as inclusions, cracks, or tissue abnormalities. In some examples, specimens are stretched or otherwise stressed by one or more light fluxes, and specimen elongation is estimated based on a series of associated speckle patterns.

Abstract: A measurement device for oscillation measurement, as well as a corresponding method, is proposed, wherein the oscillation measurement is performed by at least one laser interferometer (2, 3), whose measurement beam is directed onto various measurement points (5) of the object (1) for generating a scanning movement, and the obtained oscillation data is correlated with the position data of the respective measurement point (5) and evaluated or displayed. In particular, for three-dimensional measurements, the invention reduces the measurement complexity because the scanning device is a robot arm, which moves a measurement head of the laser interferometer to the desired measurement points on the object.

Abstract: Methods for measuring strains in circuit substrates such as circuit boards and semiconductor wafers include illuminating a specimen with a substantially collimated laser flux. A temperature change is produced in the specimen and a series of laser speckle patterns produced by a laser flux scattered or reflected by the specimen is recorded. Localized strains are detected based on speckle pattern shifts that are calculated using the recorded speckle patterns. Stains can be recorded as a function of temperature or rate of change of temperature, and strains at one or more circuit substrate locations can be detected.

Abstract: Fiber optic particle detector for measurements in a fluid flow, comprising an optical fiber (2,3,12) being acoustically coupled to a mechanical element (11,13,14) adapted to be acoustically coupled to the flow, a fiber optic interferometer (54,56) and a light source (12,51,55) providing light in said optical fiber.

Abstract: An imaging system includes: an object wavefront source and an optical microscope objective all positioned to direct an object wavefront onto an area of a vibrating subject surface encompassed by a field of view of the microscope objective, and to direct a modulated object wavefront reflected from the encompassed surface area through a photorefractive material; and a reference wavefront source and at least one phase modulator all positioned to direct a reference wavefront through the phase modulator and to direct a modulated reference wavefront from the phase modulator through the photorefractive material to interfere with the modulated object wavefront. The photorefractive material has a composition and a position such that interference of the modulated object wavefront and modulated reference wavefront occurs within the photorefractive material, providing a full-field, real-time image signal of the encompassed surface area.

Abstract: The present invention detects ultrasonic displacements includes a detection laser to generate a first pulsed laser beam to detect the ultrasonic surface displacements on a surface of the target. Collection optics to collect phase modulated light from the first pulsed laser beam either reflected or scattered by the target. An optical amplifier which amplifies the phase modulated light collected by the collection optics. An interferometer which processes the phase modulated light and generate at least one output signal. A processor that processes the at least one output signal to obtain data representative of the ultrasonic surface displacement at the target.

Abstract: An optical metrology system is provided with a data analysis method to determine the elastic moduli of optically transparent dielectric films such as silicon dioxide, other carbon doped oxides over metal or semiconductor substrates. An index of refraction is measured by an ellipsometer and a wavelength of a laser beam is measured using a laser spectrometer. The angle of refraction is determined by directing a light pulse focused onto a wafer surface, measuring a first set of x1, y1, and z1 coordinates, moving the wafer in the z direction, directing the light pulse onto the wafer surface and measuring a second set of x2, y2 and z2 coordinates, using the coordinates to calculate an angle of incidence, calculating an angle of refraction from the calculated angle of incidence, obtaining a sound velocity v, from the calculated angle of refraction and using the determined sound velocity v, to calculate a bulk modulus.

Abstract: An interferometer has a source for generating a first beam and a second beam of a coherent monochromatic light having a wavelength ?, optical elements for directing the beams through two different optical paths having a path-length difference, a detector for detection of an interference signal of the beams, and a modulator for additionally varying the path-length difference periodically to allow the interference signal be detected near a path-length difference of ?/4 periodically. A maximum intensity change in the interference signal caused by a small period change of the path-length difference is thus detectable. The maximum intensity change caused by varying the path-length difference by at least ?/2 may also be detectable. The interferometer may be used to measure small vibrations, without pre-calibration and/or a feedback servo system for keeping the path-length difference near ?/4.

Abstract: A method (1) creates charge carriers in a concentration that changes in a periodic manner (also called “modulation”) only with respect to time, and (2) determines the number of charge carriers created in the carrier creation region by measuring an interference signal obtained by interference between a reference beam and a portion of a probe beam that is reflected by charge carriers at various depths of the semiconductor material, and comparing the measurement with corresponding values obtained by simulation (e.g. in graphs of such measurements for different junction depths). Various properties of the reflected portion of the probe beam (such as power and phase) are functions of the depth at which the reflection occurs, and can be measured to determine the depth of the junction, and the profile of active dopants.

Abstract: An imaging system comprises an interferometer and an ultrasound console that processes signals from the interferometer into an image for display. The interferometer may include one or more multi-element photo detectors with a plurality of parallel outputs. A parallel to serial converter is provided between the parallel output of the interferometer and the input of the ultrasound console, to convert the signals provided on the parallel outputs into a serial signal for analysis by the ultrasound console. The interferometer may be selectively coupled to the ultrasound console and the system may further comprise an ultrasound device that may also be selectively coupled to the console, offering a user the option of using either the interferometer or the ultrasound device. The ultrasound console may also include two inputs, one for the interferometer and the other for the ultrasound device.

Abstract: A granular speck pattern is generated by a reflecting laser beam as an object to be measured is irradiated with a laser beam. This granular speck pattern is directly picked up as image index by a line sensor. An A/D converter converts an analog signal supplied from the line sensor to a digital signal, a processing unit calculates the amount of movement of the object on the basis of movement of a pixel interval of the granular speck pattern. A display device displays the amount of movement calculated by said processing unit.

Abstract: 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.

Abstract: An inspection system calibration method includes producing two sideband signals of a first wavefront; interfering the two sideband signals in a photorefractive material, producing an output signal therefrom having a frequency and a magnitude; and producing a phase modulated operational signal having a frequency different from the output signal frequency, a magnitude, and a phase modulation amplitude. The method includes determining a ratio of the operational signal magnitude to the output signal magnitude, determining a ratio of a 1st order Bessel function of the operational signal phase modulation amplitude to a 0th order Bessel function of the operational signal phase modulation amplitude, and comparing the magnitude ratio to the Bessel function ratio.

Abstract: An optical apparatus for coherent detection of an input optical beam. The apparatus includes a beam splitter for splitting the input optical beam into a first component and a second component; an optical delay device arranged to receive the second component, the optical delay device imposing an intentional delay in the second component of the input optical beam; and an adaptive beam combiner coupled to receive the second component with a delay imposed thereon by the optical delay device; and the first component from the beam splitter. The adaptive beam combiner has two exiting components having the same wavefronts and propagating directions as the first and second components and being in quadrature. A detector arrangement is provided for receiving and detecting the first and second exiting components from the adaptive beam combiner.

Abstract: The speed of sound c is determined in a material as a function of the temperature T by heating an end of an elongated sample body of the material of the temperature and determining the time difference for the receipt of echoes from two reflective zones at the heated end. The opposite end of the body is cooled in a water bath which can couple an ultrasonic test head to the body.

Abstract: In an opto-acoustic measuring device for thin films and solid surfaces, the probe beam is split into a first probe beam portion and a second reference beam portion. The splitting of the probe beam is achieved using a phase mask that also splits the excitation beam. The probe beam is aligned using a retro-reflector on a motorized stage to control the beam angle. Excitation and probe/reference beams are overlapped at the sample surface. The first probe beam portion gets diffracted by material disturbances generated by excitation beams. The diffracted part of the first probe beam portion is collinear with the second reference beam portion, resulting in heterodyning. The heterodyne signal measured by the detector is analyzed in order to determine thickness and/or other properties of a thin film or solid surface. The invention improves magnitude and reproducibility of the opto-acoustic signal which results in enhanced precision of measurements.

Abstract: An inspection system calibration method includes producing two sideband signals of a first wavefront; interfering the two sideband signals in a photorefractive material, producing an output signal therefrom having a frequency and a magnitude; and producing a phase modulated operational signal having a frequency different from the output signal frequency, a magnitude, and a phase modulation amplitude. The method includes determining a ratio of the operational signal magnitude to the output signal magnitude, determining a ratio of a 1st order Bessel function of the operational signal phase modulation amplitude to a 0th order Bessel function of the operational signal phase modulation amplitude, and comparing the magnitude ratio to the Bessel function ratio.

Abstract: In order to probe an object in motion subject to surface displacement, for example, caused by ultrasonic wave propagation, a laser beam is split into a first portion and a second portion. The first is scatted off the object to generate a signal beam. The frequency shift produced in the signal beam due to motion of the object is measured, and this is used to adjust the frequency of one or both portions of the laser beam so that both beams have substantially the same frequency. The surface displacements are measured by comparing the second portion of the laser beam and the signal beam after frequency adjustment.

Abstract: The present invention for detecting ultasonic displacements includes a detection laser to generate a first pulsed laser beam to generate the ultrasonic surface displacements on a surface of the target. A seocond pulsed laser beam to detect the ultrasonic surface displacements on a surface of the target. Collection optics to collect phase modulated light from the first pulsed laser beam either reflected or scattered by the target. An interferometer which processes the phase modulated light and generate at least one output signal. A processor that processes the at least one output signal to obtain data representative of the ultrasonic surface displacements at the target.

Abstract: A system and method for testing a physical attribute of a manufactured object that includes a laser generator and pulse generator that generate a plurality of Dirac-like pulses. The pulses, directed at an object, cause a sonic signal to be initiated indicative of the physical attribute of the manufactured object, and are detected. The system also controls the width of the Dirac-like pulses and time separation between pulses. A display may also be used to present the detected signal or physical attribute. The Dirac-like pulses are structured to produce a particular output in the manufactured object. The Dirac-like pulses may be altered dynamically in the presence of deviations from the expected output. One embodiment of the Dirac-like pulses is a series of pulses with pulse widths less than 20% a time separation between successive pulses.

Abstract: A vibrometer for probing an object to determine its vibratory signature and a method of probing same. The vibrometer includes a laser for generating a laser beam for probing the object; a detector for detecting reflections from the object; and a two beam input phase-conjugate mirror located so as to receive a portion of the laser beam produced by the laser and a portion of the laser beam reflected from the object, the two input beam phase-conjugate mirror reflecting received diffuse signals from the object back towards the object.

Abstract: The present invention for detecting ultrasonic displacements includes a detection laser to generate a first pulsed laser beam to generate the ultrasonic surface displacements on a surface of the target. A second pulsed laser beam to detect the ultrasonic surface displacements on a surface of the target. Collection optics to collect phase modulated light from the first pulsed laser beam either reflected or scattered by the target. An interferometer which processes the phase modulated light and generate at least one output signal. A processor that processes the at least one output signal to obtain data representative of the ultrasonic surface displacements at the target.

Abstract: A vibrometer for probing an object to determine its vibratory signature and a method of probing same. The vibrometer includes a laser for generating a laser beam for probing the object; a detector for detecting reflections from the object; and a two beam input phase-conjugate mirror located so as to receive a portion of the laser beam produced by the laser and a portion of the laser beam reflected from the object, the two input beam phase-conjugate mirror reflecting received diffuse signals from the object back towards the object.

Abstract: Disclosed is a system and method for providing closed-loop control of the heating of a workpiece by an induction heating machine, including generating an acoustic wave in the workpiece with a pulsed laser; optically measuring displacements of the surface of the workpiece in response to the acoustic wave; calculating a sub-surface material property by analyzing the measured surface displacements; creating an error signal by comparing an attribute of the calculated sub-surface material properties with a desired attribute; and reducing the error signal below an acceptable limit by adjusting, in real-time, as often as necessary, the operation of the inductive heating machine.

Abstract: Electronic speckle interferometry is used to detect submicron-sized indication in fabricated devices, such as membranes. Indications include indentations, deformations or defects. For example, disbonds between a membrane surface and a bonded edge surface can be detected. An acoustic source can be used to excite the membrane. The acoustic source can produce a sine wave to vibrate the membrane. An interference image of the membrane is created to show whether submicron-sized defects exist in the membrane.

Abstract: An imaging system includes: an object wavefront source and an optical microscope objective all positioned to direct an object wavefront onto an area of a vibrating subject surface encompassed by a field of view of the microscope objective, and to direct a modulated object wavefront reflected from the encompassed surface area through a photorefractive material; and a reference wavefront source and at least one phase modulator all positioned to direct a reference wavefront through the phase modulator and to direct a modulated reference wavefront from the phase modulator through the photorefractive material to interfere with the modulated object wavefront. The photorefractive material has a composition and a position such that interference of the modulated object wavefront and modulated reference wavefront occurs within the photorefractive material, providing a full-field, real-time image signal of the encompassed surface area.

Abstract: The present invention is a nondestructive and quantitative laser ultrasonic laser apparatus and associated method for determining adhesion quality of a coating on a substrate. The apparatus of the invention is preferably a pulsed laser for generation and Michelson-type interferometer based system and includes a rotary probe head assembly for making evaluations within a cylindrical test specimen. The method of the invention includes data analysis that uses acquired data from the ultrasonic laser apparatus and computes the dispersion relation or curves (frequency versus velocity) using a ridge-following technique in wavelet analysis and from this, outputs the adhesive quality of the coating by comparing it with a theoretically based determination of a particular coating/substrate bond system. The invention is used for evaluating adhesion quality of coatings used in a gun bore.

Abstract: A method for studying vibrational modes of an electro-acoustic device includes driving the electro-acoustic device to produce at least one vibrational mode therein, collecting phase and amplitude data from the electro-acoustic device using optical interferometry, and mapping the at least one vibrational mode based upon the collected phase and amplitude data. The phase and amplitude data may be processed to provide an instantaneous three-dimensional view of the at least one vibrational mode. Furthermore, a sequence of instantaneous three-dimensional views may be constructed to form a motion picture of the at least one vibrational mode. Additionally, collecting may include raster scanning to provide phase and amplitude data across a surface of the electro-acoustic device.

Abstract: Laser ablation combined with spectrometric analysis is a good tool for determining the composition of heterogeneous materials. By measuring the depth of an ablation crater at a target of a heterogeneous material, it is possible to generate a compositional profile as a function of the depth. It is also possible to generate a 3 dimensional profile by depth profiling of a plurality of craters. The depth measurement is conducted in situ and in real time so that the evolution of composition as a fucntion of the depth can be measured. An interferometric technique with a short coherence length light is one of the preferred embodiments for measuring the depth in situ and in real time.

Abstract: A method for the determination of grain orientation in a film sample is provided comprising the steps of measuring a first transient optical response of the film and determining the contribution to the transient optical response arising from a change in the energy distribution of the electrons in the sample, determining the contribution to the transient optical response arising from a propagating strain pulse within the sample, and determining the contribution to the transient optical response arising from a change in sample temperature of the sample. The grain orientation of the sample may be determined using the contributions to the transient optical response arising from the change in the energy distribution of the electrons, the propagating strain pulse, and the change in sample temperature. Additionally, a method for determination of the thickness of a film sample is provided. The grain orientation of the sample is first determined.