Abstract: The invention is directed to a system and a method for testing a physical attribute of a manufactured object. The system comprises at least one laser generator and a pulse generator that generate a plurality of Dirac-like pulses. The pulses are directed at an object, causing a sonic signal to be initiated. The sonic signal is indicative of the physical attribute of the manufactured object and it is detected by a detector and the signal. The system may also comprise a controller for controlling the width of the Dirac-like pulses and a time separation between pulses. The system may also comprise of a display for representing the detected signal or the physical attribute. The invention is also directed to a laser ultrasound testing device that generates a plurality of Dirac-like laser pulses, directs the pulses at a manufactured object, and measures a resulting ultrasound signal indicative of a physical attribute of the object.

Abstract: The invention is directed to a wave characteristic adjusting device used to compensate for a wave characteristic distortion caused by the scanning motion of a probe beam of a two-wave mixing interferometer. The invention is also directed to an apparatus and method for using the wave characteristic adjusting device in a rapid scanning laser ultrasound testing device. In a rapid scanning laser ultrasound testing device, a laser pulse is directed at periodic points along a path across the surface of a manufactured object. The laser pulse initiates an ultrasonic signal associated with the manufactured object. An interferometer may be used to measure the initiated ultrasonic signal. The interferometer scans a probe beam along a path similar to the sonic initiating laser. A pulse of the probe beam is directed at the manufactured object in the vicinity of the initiating laser pulse while continuously scanning. As a result, the probe beam pulse may exhibit a Doppler shift.

Abstract: The invention provides for ultrasonically measuring the porosity in a sample composite material by accessing only one side of the sample composite material and includes the steps of measuring a sample ultrasonic signal from the sample composite material, normalizing the sample ultrasonic signal relative to the surface echo of the sample composite material, and isolating a sample back-wall echo signal from the sample ultrasonic signal. A sample frequency spectrum of the sample back-wall ultrasonic signal is then determined. Next, the method and system include the steps of measuring a reference ultrasonic signal from a reference composite material, normalizing the reference ultrasonic signal relative to the surface echo of the reference composite material; and isolating a reference back-wall echo signal from the sample ultrasonic signal. A reference frequency spectrum of the reference back-wall ultrasonic signal is then determined.

Abstract: A system and method for generating ultrasonic displacements on a remote target. The method of the present invention includes the steps of first using a laser to generate a beam having a first wavelength to produce ultrasonic displacements at the remote target. This laser beam will have a first wavelength which can be modulated to alter characteristics of the ultrasonic displacements. These ultrasonic displacements at the remote target can be optimized to enhance the detection optics for collecting phase modulated light from the second pulsed laser beam either reflected or scattered by the remote target; an interferometer to process the phase modulated light and generate at least one output signal, and means for processing the at least one output signal to obtain data representative of the ultrasonic surface displacements on the surface of the remote target.

Abstract: A system and method for generating a desired acoustic frequency content in a laser-generated ultrasonic wave emitted from a target in response to a laser pulse. The method includes generating a generation laser pulse using a laser source. An optimal wavelength &lgr;0 for the generation laser pulse is determined using a computer. The optimal wavelength data is determined from material-specific, empirically calculated data stored in a storage device that is accessible to the computer. An optimal laser pulse is generated by shifting the generation laser pulse to the optimal wavelength &lgr;0. The optimal laser pulse is directed to the target to generate the laser-generated ultrasonic wave with the desired frequency content.

Abstract: An ultrasonic transducer having a transducer element which generates ultrasonic energy propagating along a transducer axis with a predetermined speed of propagation, and a lens acoustically coupled to the transducer element and having an input face positioned to receive the ultrasonic energy, wherein the lens includes electrorheological fluid with voltage dependent acoustic properties therein for enabling the speed of propagation to be selectively controlled as the ultrasonic energy passes through the lens. The transducer may include a focusing lens, a steering lens, or a combination thereof for selectively controlling the focusing and/or steering of the ultrasonic energy within a region of interest in an object to be inspected therewith. A voltage control device is used to controllably apply voltage to the lens to control the propagation speed as the ultrasonic energy passes therethrough.

Abstract: The present invention discloses a high density interconnect for an ultrasonic phased array and method for making. The high density interconnect includes a backfill material having grooves formed therein. Each of the grooves are separated a predetermined distance from each other and have a predetermined groove depth. A conducting material is deposited in each of the grooves. The grooved backfill is cut or formed into sections having different lengths. The sections are then reconsolidated into an unitary structure, wherein one end of the structure is electrically conductive in one direction. One surface of the high density interconnect is metallized for bonding with an ultrasonic phased array transducer while the other side is patterned with solder bumps for connection to integrated circuit boards or flexible circuit boards.

Abstract: The present invention discloses an acoustic composite material for an ultrasonic phased array and a method for making. The acoustic composite material is formed from a microcapillary array having a plurality of holes of a constant cross-section and volume fraction. In each of the plurality of holes of the microcapillary array, a polymer fill is deposited therein. The polymer filled microcapillary array is cut at an axis perpendicular to the microcapillary array into a plurality of sections. Each of the plurality of sections are then ground into a predetermined thickness and bonded to a phased array of piezoelectric elements and backfill material.

Abstract: A high yield method of fabricating an ultrasound array having densely packed ultrasound elements with smooth surface finishes includes the steps of: 1) applying an acoustic matching material to opposites faces (or surfaces) of a piezo electric material ceramic block; 2) cutting the block in a plane perpendicular to the two faces of the block so as to form a plurality of wafers having the acoustic matching material disposed on opposite ends; 3) assembling the wafers to form a laminated body having respective portions of the matching layer on opposite surfaces and with the wafers each being separated from an adjacent wafer by a selected gap distance and bonded together by a polymeric adhesive material; 4) cutting the laminated body along a longitudinal axis so as to form a first laminate body subassembly and a second laminate body subassembly, each of the subassemblies having a front surface having the acoustic matching material disposed thereon and a back surface where the laminate body was cut; 5) applying a

Abstract: An ultrasonic transducer having a transducer element which generates ultrasonic energy propagating along a transducer axis with a predetermined speed of propagation, and a lens acoustically coupled to the transducer element and having an input face positioned to receive the ultrasonic energy, wherein the lens includes electrorheological fluid with voltage dependent acoustic properties therein for enabling the speed of propagation to be selectively controlled as the ultrasonic energy passes through the lens. The transducer may include a focusing lens, a steering lens, or a combination thereof for selectively controlling the focusing and/or steering of the ultrasonic energy within a region of interest in an object to be inspected therewith. A voltage control device is used to controllably apply voltage to the lens to control the propagation speed as the ultrasonic energy passes therethrough.

Abstract: An ultrasonic transducer with a magnetostrictive lens for dynamically focussing and steering a beam of ultrasound energy is provided. The magnetostrictive lens is operable in response to a magnetic field generated by a coil such that the speed of propagation of the ultrasound beam is selectively controlled as the beam passes through the lens. The lens can be made up of first and second prisms wherein at least one of such prisms is magnetostrictive. Alternatively, the lens can be made up of an individual stage made of a composite having a plurality of elongated rods of magnetostrictive material cooperating in response to the control signal applied to the lens for selectively controlling the propagation speed of the ultrasound beam passing therethrough.

Abstract: An ultrasonic transducer with a selectable center frequency is provided. The transducer is made of a composite including a piezoelectric base and a plurality of elongated rods made of a material having a coefficient of elasticity substantially responsive to a control signal applied thereto. In one embodiment the rod material is a suitable magnetostrictive alloy in which case the control signal is a magnetic field. In another embodiment, the rod material is a suitable shape memory alloy in which case the control signal is a thermal signal. In either case, the level of the respective control signal, i.e., the level of the magnetic field or the temperature level, allows for selectively shifting the center frequency of the ultrasound beam produced by the transducer.