Abstract: A weld pool viewing system including optical elements for enhancing the weld pool image is positioned at an angle relative to the axis of a welding torch to extract image information pertaining to the interface of the weld pool with a workpiece to control the welding parameters.

Abstract: A method for defining an array of light-emitting pixels in a thin film electroluminescent edge emitter structure includes the steps of moving the structure in proximity to a stationary first laser source as the first laser source is operated to generate a plurality of first laser pulses. The plurality of first laser pulses are focused into "lines" of light energy that strike the structure at a plurality of spaced apart locations in succession to ablate a predetermined number of layers of the structure. This ablation process forms a plurality of spaced apart channels in the structure. The portions of the structure remaining between each pair of adjacent channels define an array of pixels in the structure. The structure having the pixels formed therein is moved in proximity to a second laser source. The second laser source is movable in a selected direction substantially perpendicular to the direction of movement of the structure.

Abstract: A laser welding system is disclosed in which a high power laser produces the laser beam for delivery to a weld site. A transmitter is optically coupled to the laser and directs the laser beam to a spatially separated receiver. The receiver has an input alignable for receiving the directed laser beam and including optics for delivering the laser beam to the weld site. A pair of directable beam deflectors are employed for aligning the transmitter and the receiver. A pair of steering deflectors introduce the laser beam into the transmitter. A selectable mounting allows the laser to be secured at various orientations relative to the steering mirrors and the weld site. The transmitter and the receiver each have a detector positioned for receiving an alignment laser beam at a point which indicates alignment. The transmitter and the receiver include steppable drives for positioning their respective deflectors. The alignment laser is aligned at a starting block on the receiver detector and the transmitter detector.

Abstract: A system which utilizes a source of ultraviolet radiation to mark a surface or to cure selectively a photosensitive paint applied to a surface. The source of UV light is either a laser or a broadband source and the light is controlled by an aperture and/or a stencil apparatus. The photosensitive paint is applied by a controlled technique as a protective or a decorative coating.

Abstract: In one embodiment, a laser welding head is formed of a hollow tubular housing, and includes multiple focusing means for refocusing and realigning the laser beam if it is misaligned relative to the axis of the housing. In another embodiment, the housing is formed of a plurality of flexibly interconnected segments having at least one focusing means in each segment for realigning the beam and for directing the laser beam along interconnected linear paths.

Abstract: A detector for aligning a laser beam has been provided. The detector includes an insulative substrate, and a thermally conductive planar face attached to the substrate. The face is divided into thermally isolated sectors, each sector having the same shape and area. A corresponding thermal sensitive device is provided for each sector. Each sector is in thermal contact with a corresponding one of the thermal sensitive devices, and each thermal sensitive device produces a response proportional to the amount of laser energy impinging thereon to thereby provide indication of the misalignment of the laser beam relative to the transport path.

Abstract: A controlled depth laser drilling system for a workpiece containing metallic conductors is provided having at least one laser beam (56 and/or 57 of FIG. 5) where a portion of the laser beam (44) will be reflected from the workpiece and back to a drilling depth monitoring means (43) containing optical means capable of reflecting a portion of the original and reflected laser beams into radiation detector means (46', 46" and/or 45', 45"), where the detector means are capable of converting the radiation received into a measurable electrical signals.

Abstract: A method and apparatus for aligning laser cavity and transport optics with one or more targets is disclosed. An alignment beam is deflected from its initial path and is rotated about the alignment axis in an annular sweep. Detectors circumferentially located about a desired point located relative to the target are responsive to the intensity of the rotatig alignment beam for producing corresponding outputs. The cavity optics and transport optics may be adjusted relative to the target so that the output of the detectors are the same thereby assuring that the various respective optics are aligned with the target.

Abstract: A system is disclosed for aligning a high-power laser apparatus to transmit a high-power beam along an optimum beam path to an adjustable remote beam receiver and for aligning the beam receiver for optimum reception of the high-power beam. A low-power visible laser is directed along the path to be followed by the high-power laser and a viewer such as a video camera is used for rough alignment. A pellicle, a partially reflecting mirror, and three low-power beam detectors are used with the low-power laser to align the beam transmitter with the beam receiver. Alignment of the beam receiver with the beam transmitter is checked by a high-power laser beam alignment checking system. This alignment checking system employs an annular beam detector mounted near the beam transmitter and a second beam detector mounted near the beam receiver.

Abstract: A laser welding head for welding a sleeve within a tube by fusing the interface between the sleeve and tube with a laser beam. The laser welding head has a cylindrical housing adapted to be inserted inside of the sleeve, a focusing lens for focusing a laser beam transmitted through the housing, and a welding mirror for directing the focused beam out of the housing and into contact with the sleeve. The welding mirror is maintained a predetermined distance from the inside surface of the sleeve and a motor and drive assembly are used to rotate the welding head within the sleeve. Shield gas is supplied to the welding head and passes about the periphery of the focusing lens for cooling the focusing lens and the welding mirror before being discharged into contact with the weld area. A recessed aperture is provided within the discharge outlet to prevent molten material from the weld site from splattering into the housing and onto the mirror or lens.

Abstract: A method for welding a sleeve within a tube of a steam generator, the sleeve being in close contact with the tube. A welding head of a weld head apparatus is positioned within the tube at a predetermined weld site, a laser beam is directed to the welding head, the beam is focused with a focusing means, the focused laser beam is reflected with a welding mirror means into contact with a portion of the sleeve to be welded to the tube, the welding mirror means is maintained a predetermined focal distance from the inside surface of the sleeve, and the welding head is rotated to complete a weld fusion path about the inner periphery of the sleeve. Shielding gas is used to shield the weld site. A robotic arm positions the weld head apparatus within the steam generator. At each end of the sleeve, multiple discrete weld paths or a continuous helical multiple weld path are welded.

Abstract: A laser welding beam transport system is provided in which the laser beam 14 emanating from the laser generator 10 is expanded in diameter in an expander 16 at a location close to the generator, and then is transported in its expanded diameter to a remote location where the beam is reduced in diameter in a beam reducer 26 at a location close to the welding station 28 for the purpose of maintaining a relatively constant power density of the beam at the station over a significant range of working travel of the working station.

Abstract: Apparatus is disclosed for aligning a laser beam used to perform laser machining operations. The aligning apparatus of this invention is used with laser machining apparatus comprising a laser for emitting a laser beam along a path and a laser lens assembly disposed within the path and movable along an axis for variably focusing the laser beam at a plurality of different focal spots corresponding to the plurality of laser machining operations. The alignment apparatus takes the form of an adjustable mirror, which is disposed to intercept the laser beam and to align at least a portion of the path with the axis of the laser lens assembly, whereby the lateral displacement of each of said plurality of focal spots from the axis is reduced as the laser focusing assembly is moved along its axis.

Abstract: A machine manipulates a laser beam substantially transversely across a moving sheet of flat or curved material. This machine includes a rotating optical system which focuses and moves an elongate beam spot across the moving sheet of flat or curved material, at a high rate of speed. In methods of applying these instruments to produce reductions in watt loss in coated ferromagnetic sheet without damage to the coating, the speed of laser scanning, S.sub.2 (inches/minutes), and the incident power, P (watts), of the beam are selected such that the function, PS.sub.2.sup.-1/2 is between about 0.1 to about 7.

Abstract: The operation of a two-photon, three level laser system at high temperatures or pressures is made possible by reducing the build up time of the flux of the second lasing transition in the laser discharge region.

Abstract: A plurality of pivotal reflectors direct a high-power laser beam onto a workpiece, and a rotatable reflector is movable to a position wherein it intercepts the beam and deflects a major portion thereof away from its normal path, the remainder of the beam passing to the pivotal reflectors through an aperture in the rotating reflector. A plurality of targets are movable to positions intercepting the path of light traveling to the pivotal reflectors, and a preliminary adjustment of the latter is made by use of a low-power laser beam reflected from the rotating reflector, after which the same targets are used to make a final adjustment of the pivotal reflectors with the portion of the high-power laser beam passed through the rotating reflector.

Abstract: The operation of a two-photon, three level laser system at high temperatures or pressures is made possible by reducing the build up time of the flux of the second lasing transition in the laser discharge region.

Abstract: The depletion of energy stored in the transfer gas component of a low pressure, short pulse laser system following excitation of the laser gas medium consisting of a lasing gas component and a transfer gas component is achieved by extracting a plurality of output pulses by providing a sufficient delay between output pulses to permit the transfer of energy from the transfer gas component to the lasing gas component.

Abstract: The direct electrical discharge excitation, pulsed or CW, of a laser gas medium consisting of CO.sub.2 :N.sub.2 :He present in the approximate ratio of 1:2:25 at a total gas pressure of between approximately 8 and 12 Torr and an operating temperature between approximately 125.degree. K. and 150.degree. K. supports 16 micron laser radiation on the 02.sup.0 0.fwdarw.01.sup.1 0 CO.sub.2 vibrational transition, and 14 micron laser radiation on the 10.sup.0 0.fwdarw.01.sup.1 0 CO.sub.2 vibrational transition.

Abstract: An automated system for transporting nuclear fuel elements between fuel element assembly stations without contaminating the area outside the sealed assembly stations. The system comprises a plurality of assembly stations connected together by an elongated horizontal sealing mechanism and an automatic transport mechanism for transporting a nuclear fuel element in a horizontal attitude between the assembly stations while the open end of the fuel element extends through the sealing mechanism into the assembly station enclosure. The sealing mechanism allows the fuel element to be advanced by the transport mechanism while limiting the escape of radioactive particles from within the assembly station enclosure.