Textron Systems Corporation

Textron Defense Systems, Division of Avco Corporation

Daniel E Klimek

Petros Amestis Kotidis

Alexander E Mandl

Jaime A Woodroffe

Paul Fred Gozewski

James Frederick Cunningham

Charles Borsody

Brian W Anthony

Agostino Abbate

Richard Hayes

In a system and method, the emitted beams of multiple diode bar array assemblies are combined to achieve an increase in the resulting power density in the combined output beam, while addressing the need for heat distribution in each of the individual assemblies. The present invention enables the combination of output planes of illumination, to form a single, merged beam of area Ahaving intensity I&#x2dc;M*Iand brightness B&#x2dc;M*B, where Iand Brefer respectively to the intensity and brightness of the output plane of illumination of a single stacked array, and where Iand Brefer respectively to the intensity and brightness of the combined output plane of illumination of M stacked arrays. In this manner, the present invention is useful in applications where there is a need for high-intensity, high-brightness light energy.

Beam combination using interleaved optical plates

A zig-zag laser has the ability to generate a high power beam while effectively removing heat without degrading the beam quality. The laser has a series of gaps interposed between the thin slabs, the gain medium, and between the thin slabs and the quartz windows to receive coolant and cool the cell assembly. The coolant flows transversely relative to the path of the laser and the flow of the coolant is in the opposite direction on each side of the thin slab to minimize the temperature gradient. The gaps in conjunction with the inner channel portions in the secondary manifold flow the coolant through the cell assembly in a laminar manner therein not degrading the laser beam quality. A transparent quartz/quartz interface between the secondary manifold and the cell assembly allow the fluorescence to move away from the cell assembly and minimizes heat in the cell assembly.

Zig-zag laser with improved liquid cooling

Amplified spontaneous emission (ASE) ducts are disclosed for use with various gain media. An ASE duct may be configured and arranged to remove ASE from solid state or liquid gain media and transmit the ASE to an exterior optical medium. The refractive index of an ASE duct is selected as desired based on the refractive index of a gain medium and an exterior optical medium. An ASE duct may include first and second boundary surfaces joined at a vertex having an included angle that allows ASE (light) reflected off on one boundary surface to be incident on the another boundary surface at less than the critical angle and transmitted outside of the ASE duct. Laser systems using ASE ducts and methods of using and manufacturing ASE ducts are disclosed.

Amplified spontaneous emission ducts

Embodiments of the present invention are directed to staggered arrays of laser diode bars positioned on stepped support structures. Optical waveguides may direct the outputs of the individual diode bars to a desired location, for example, a common output plane. The optical waveguides may be glass plates in certain embodiments. Waste heat generated by the diode bars may be removed from the support structures at certain locations and as a result, the diode bars may be closely positioned with respect to each other. By closely positioning the laser diode bars and directing the diode bar outputs to a desired orientation, the effective brightness and fluence may be increased for a given output area and operational power compared to the prior art. Associated methods of manufacturing staggered array couplers and producing high-power pump energy are also described.

Staggered array coupler

In an apparatus and method for remote ultrasonic determination of thin material properties using signal correlation, a method and apparatus are provided by which an arbitrarily-oriented anisotropic thin material may be interrogated for characterizing an unknown material property value thereof. The unknown material property may comprise for example temperature, pressure, elastic constants, density, hardness, composition, crystal orientation, grain size, and residual stress, or any material property that is variable with respect to known physical parameters of the material, for example known material elastic constants and/or density. In a first embodiment, theoretical signals are generated, for example a theoretical signal matrix, to characterize a material property value of a thin anisotropic material. A model of the thin material is generated comprising the behavior of the known material physical properties as functions of the unknown material property value to be characterized. For a plurality of known material thicknesses and known material property values, a transduction mechanism is simulated at a source location for generating a simulated elastic stress wave operating on the model at a plurality of source locations. The simulated intensities of signals generated by the simulated elastic stress waves are computed at a sense location to provide a representative composite signal. Theoretical signals are determined from the composite signal at each thickness and at each material property value. In a second aspect, the present invention is directed to a method for empirical characterization of a transduction event in a thin material using iterative temporal decomposition of an initial estimate of the transduction event converging on a measured signal.

Apparatus and method for remote ultrasonic determination of thin material properties using signal correlation

In an apparatus and method for remote ultrasonic determination of thin material properties, a match filter calibration technique is employed. For a plurality of known material property values and known material thicknesses, an elastic stress wave is generated in the material at a source location. The intensity of a signal generated by the elastic stress wave is sensed at a sense location positioned a known distance from the source location. A feature is selected from among the sensed signals which demonstrates minimal thickness dependents from a plurality of known material thicknesses. The selected feature is applied to the sensed signals to determine propagation time of the signals over the known distance. A calibration curve is then generated to characterize the relationship between signal propagation time and material property value for each material thickness. The present technique is especially amenable to determination of thin material properties, for example temperature, in a manner which is independent of material thickness. In an embodiment adapted for determination of temperature, precision on the order of &plusmn;1&deg; C. is achievable over a range of material thicknesses.

Match filter apparatus and method for remote ultrasonic determination of thin material properties

A method and apparatus for interferometrically monitoring a target to determine, in accordance with predetermined criteria, an occurrence of a period of time that is optimum for obtaining a data point. In response to detecting such a period an impulse source, such as an impulse laser (14), is triggered to launch an elastic wave within the target so that a data point can be obtained.

Laser ultrasonics-based material analysis system and method utilizing

Disclosed herein is an interferometric-based materials analysis system (10) that employs a novel combination of laser beam shaping and pointing techniques, the use of a low cost, rugged, and compact diode laser (22) as a detection laser, and the use of signal processing techniques that compensate for inherent instabilities and short-term drift in the diode laser. A matched filter processing technique is disclosed for processing interferometrically-obtained data points from a target being analyzed. The matched filter technique is shown to be especially useful for detecting and analyzing Lamb modes within thin targets, such as a silicon wafer undergoing a rapid thermal processing cycle. Also disclosed is a method and apparatus for interferometrically monitoring a target to determine, in accordance with predetermined criteria, an occurrence of a period of time that is optimum for obtaining a data point. In response to detecting such a period an impulse source, such as an impulse laser (14), is triggered to launch an elastic wave within the target so that a data point can be obtained. A plurality of data points so obtained are subsequently processed, such as by the matched filter technique, to determine a property of interest of the target. The property of interest may be, by example, the temperature of the target or the metallurgical status of the target.

Ultrasonic-based material analysis using an annular impulse beam

Disclosed herein is an interferometric-based materials analysis system (10) that employs a novel combination of laser beam shaping and pointing techniques, the use of a low cost, rugged, and compact diode laser (22) as a detection laser, and the use of signal processing techniques that compensate for inherent instabilities and short-term drift in the diode laser. A matched filter processing technique is disclosed for processing interferometrically-obtained data points from a target being analyzed. The matched filter technique is shown to be especially useful for detecting and analyzing Lamb modes within thin targets, such as a silicon wafer undergoing a rapid thermal processing cycle.

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Lexington, MA, United States of America

Daniel E Klimek