Abstract: A method of providing laser controlled real-time optics and optic systems for a laser beam or beams utilizing near resonance nonlinear dispersion in a collision dominated gaseous medium. Refractive optical elements may be provided that function as spherical or curved reflectors and refractive lens or prisms for expanding or contracting a laser beam or beams as well as providing gratings for providing partial or total reflection or deflection of a laser beam. The generation of a grating in accordance with the invention permits total deflection of large cross-section and powerful laser beams by the investment of a moderate amount of power. Real-time color holographic displays may also be provided and phase front aberrations caused by a laser amplifier may also be corrected.

Abstract: A laser method of and apparatus for providing a wide variety of laser wavelenghts wherein a pump source of laser radiation is sequentially Strokes-shifted in two separate cells each containing a different molecular or atomic Raman active gas, wherein each cell is optimized to produce primarily first-Stokes radiation as by variation of focal length parameters and/or gas pressure, filter means are provided at the output of the first cell to reject the pump laser radiation and to pass the first-Strokes radiation of the first cell and further filter means are provided at the output of the second cell to reject the first-Stokes radiation of the first cell and pass the first-Stokes radiation of the second cell to provide a desired output laser radiation.

Abstract: Gaseous lasers and their operation wherein during operation in the saturated regime Zeeman reorientation collisions do not occur rapidly compared to the rate at which population is transferred out of their upper lasing level and there exists a static magnetic field of predetermined minimum strength inside the lasing region that is preferably at, or substantially at, the magic angle (approximately 54.70) with respect to the predominate polarization of the laser light in the lasing cavity.

Abstract: A preferably fully impregnated dispenser cathode member or the like forming part of an electron tube, electron beam generator or the like is initially heated by any suitable means to a temperature sufficient for low level electron emission from its rear surface. A hot plate member of preferably equal size is disposed behind the cathode and can either be part of or the means for initially heating the cathode member or it can be heated with the cathode member to the aforementioned cathode member's rear surface low level emission temperature. A sustainer voltage is applied between the cathode member and the hot plate member sufficient to draw a current comprising electron flow from the cathode member to the hot plate member across the space separating them.

Abstract: A method and apparatus for transforming an obscured beam into a uniform intensity pattern at the image plane of the apparatus are described. Apparatus for carrying out the invention comprises two on-axis optical elements which are designed for stigmatic imaging of an incoming obscured parallel laser beam. The first element, a paraboloid mirror, forms an imaginary stigmatic image of the beam at its focal point. The second element, a multi-faceted mirror, comprises identical flat facets disposed on an ellipsoid envelope. The ellipsoid conjugates the focal point of the paraboloid and the image plane. Selection of an image shape and dimension defines the shape and dimension of the facets. Each facet's contribution to the image is a full scale centered spot. The contribution of each facet add up to form a final uniform image. Slight variation of the image dimension, from facet to facet, allows a roll-off of the image and compensates for diffraction ripples by the edges of the facets.

Abstract: Pulverized carbonaceous material such as coal while flowing through a reactor dispersed in a carrier gas substantially transparent to radiant energy and at atmospheric pressure is heated, typically for a few milliseconds to about 1500.degree. K., by thermal radiation while maintained in the cooler carrier gas to selectively heat the pulverized material, while cooling the volatile products as they diffuse into the cooler carrier gas, followed by quenching where necessary. In the case of coal, the principal result of this treatment is a radical increase in the easily soluble fraction of the coal with substantially no net change in the solid ultimate or proximate characteristics and substantially no output gaseous volatile production.

Abstract: A rotary indexing device for indexing a member, such as a shaft, into operative working positions in which the shaft carries a plurality of indexing arms for selecting different working positions. Final positioning means for each indexing arm comprising a solenoid actuated, pneumatic operated pin for engaging the indexing arm and effects final adjustment of the indexing arm which is brought to approximately its proper position by a servo-motor. Means are also provided to provide positive confirmation that each step of the indexing operation has been properly completed to insure that the shaft has been rotated to and is in its proper position.

Abstract: A method for laser melting of silicon for the production of boules pulled from a pool of liquid ultraclean or ultrapure silicon wherein the boules are used for producing silicon wafers suitable for use in the electronics field. A laser beam, preferably P polarized, is directed at an angle of about 88 degrees to the normal to the surface of silicon disposed in conventional melting apparatus. A suitable mirror is preferably provided to capture and reflect that portion of the laser beam reflected from the surface of the pool. Use of the present invention permits continuous operation by adding solid silicon and melting it at the point of impingement of the laser beam with up to about 96% absorption of laser energy at this point, thereby permitting the provision of heat in a very controlled manner in a continuous ultraclean silicon crystal growth process.

Abstract: This invention is directed to a method of and apparatus for heat treating axisymmetric surfaces such as inner and outer surfaces on pipes, shafts, gears, valve seats and the like with a laser beam. An annular laser beam is provided and caused to impinge on a segmented generally conical mirror which focuses and/or directs the laser beam onto the desired surface of a work piece as an annular or ring-shaped beam with a predetermined width and energy profile. Relative movement about the axis of the laser beam may be provided between the work piece and the laser beam to average any intensity distributions around the laser beam. Additionally, relative movement along the axis of the laser beam may also be provided between the work piece and the laser beam in the case of shafts, pipes and the like to provide uniform and non-overlapping coverage of the surface to be treated.

Abstract: Properties of the surface of low melting substrate parts including low melting, high conductivity reactive metal parts, are modified by forming an alloy casing thereon having the metal of the substrate as a first (matrix) component thereof together with a higher melting material as the second (reinforcing) component. The higher melting component is coated on the substrate, melted under laser heating, with gas shielding to avoid oxidation, and mixed with a melted portion of the substrate through convective circulation and the mixture is rapidly cooled to produce the alloy casing. Then the casing may be rescanned with the laser beam to rapidly melt and resolidify the casing with refined grain structure. Such grain refining may also be applied to uncoated substrates.

Abstract: In an apparatus for treatment of a process flow by beams of ionizing radiant energy, drag elements are provided for slowing flow velocity to achieve equal treatment of all portions of the process flow.

Abstract: An electron beam device having a vacuum chamber in which an electron beam generator generates a directed stream of electrons. An electron beam window comprising a foil which seals the vacuum chamber is in the path of the stream of electrons and permits passage of the stream of electrons into a working region exterior of the chamber and adjacent the electron beam window. An electrode is positioned closely adjacent the foil and a second electrode is spaced from the foil to form an elongated working or, in the case of a laser, a lasing region between them. The electrodes are maintained at a high electrical potential which, along with the electron beam, molecularly excites a gaseous working medium between the electrodes. The included angle of electrons passing through and scattered by the foil is limited and the electron beam confined to a desired region by an external shield or bezel overlying the foil.

Abstract: An image sensor, suitable for resolving a high-resolution image, comprises an arrayed plurality of image sensor modules of moderate individual resolution. The high-resolution image is subdivided into contiguous sub-images, each of which is minified before being projected upon an image sensor module. This avoids bars of blindness between the fields of view of the image sensor modules, and also facilitates production and repair of the image sensor.

Abstract: The working parts of a flowing gas laser are enclosed within an airtight housing comprising a first plenum separated from a second plenum. Blower means comprising one or more modules is provided with gas inlet means for receiving gaseous lasing medium from the second plenum and gas outlet means for exhausting the lasing medium to the first plenum. Means defining a lasing region are provided with gas inlet means for receiving lasing medium from the first plenum and gas outlet means for exhausting the lasing medium to the second plenum. The blower means provides a differential pressure across the lasing region sufficient to provide the desired flow of lasing medium through the lasing region. Due to the action of the blower means, lasing medium is caused to circulate from it to and through the lasing region and back to and through the blower means.

Abstract: The parent gas to be purified is passed end-to-end through a porous electrically conductive cylinder or its equivalent having a small wire electrode disposed along its longitudinal axis. A voltage is applied between the cylinder and wire sufficient to produce a corona discharge and ionize gas in the vicinity of the wire. Substantially only contaminants having an ionization potential less than that of the parent gas are or remain ionized and due to the electric field producing the corona discharge, are simultaneously caused to move toward the cylinder. Similarly, only electronegative gases become negatively charged in a negative corona and are likewise removed. A slightly lower pressure is maintained outside the cylinder effective to capture and remove the contaminant that has migrated to or adjacent the inner surface of the cylinder along with a small amount of the parent gas. Purified gas exits from the outlet of the cylinder.

Abstract: For use in a pulsed-laser lidar such as a laser ceilometer, there are shown several examples of signal processing means for separating desired pulses due to targets such as clouds from strong background signals due to suspended particles causing poor visibility. The several examples belong to a class of means having the property of applying, to an electrical signal pulse waveform, a time-distributed signed electrical weighting function having negligible total weight, with alternations of sign of weights separated by intervals of the order of the width of the desired pulses.

Abstract: In a pulsed gas laser, pulses of electrical or other energy are desirably converted in part into pulses of quantum mechanical pumping of the lasable gas, and unavoidably converted in part into pulses of heating of the lasable gas. According to this invention, efficiency and economy of operation are enhanced by exploiting the pulses of heating to propel and recirculate the gas through cooling means to freshen it thermally for further cycles of lasing, utilizing a structure comprising an acoustically tuned duct and an acoustic diode to establish proper phasing and direction of the pulsed and recirculating operation. The invention, although applicable to other gas lasers, is particularly applicable to electron beam ionized, electrical current sustained lasers. The invention reduces if not eliminates the cost, bulk and other disadvantages of a mechanical pump or other conventional recirculation equipment.

Abstract: A process and apparatus for gasification of carbonaceous matter, preferably coal, is disclosed. In one embodiment, a stream of previously produced char, preferably produced from coal or other fuel, together with an oxidizer and steam is introduced into a combustion stage. The combustion gas produced by the combustion passes into a mixing zone and thence with high turbulence into a gasification zone or stage at subsonic velocity. Pulverized carbonaceous matter, preferably coal, is introduced and dispersed in the combustion gas in the mixing zone. The temperature, velocity and velocity changes principally of the gas in the gasification zone or stage are controlled to provide a heating rate for the particles of pulverized carbonaceous matter of at least about 10.sup.5 degrees Kelvin per second, and to effect rapid removal of volatile components from the immediate vicinity of the particles.

Abstract: A process and apparatus for gasification of carbonaceous matter, preferably coal, is disclosed. A stream of previously produced char, preferably produced from coal, or other fuel together with an oxidizer and steam is introduced into a first or combustion stage. The combustion gas produced by the combustion passes into a second or gasification stage and through a nozzle at at least sonic velocity. Pulverized carbonaceous matter, preferably coal, is introduced and dispersed in the combustion gas in the gasification stage. The temperature, velocity and velocity changes principally of the gas in the gasification stage are controlled to provide a heating rate for the particles of pulverized carbonaceous matter of at least about 10.sup.5 degrees Kelvin per second, and to effect rapid removal of volatile components from the immediate vicinity of the particles.

Abstract: A laser mirror adapted to prevent astigmatism of reflected laser beams where the mirror is used for "folding" the laser beam such that the incident laser beam direction is not normal to the reflective surface of the mirror. This is accomplished by the provision of slots of specified dimensions in the rear surface of the mirror that in use are disposed parallel to the major axis of the laser beam's image on the mirror. In this manner, the mirror is provided with two bending stiffnesses, one in the direction of the major axis that is greater than that in the direction of the minor axis such that the bending due to heating of the mirror in the direction of both axes is made at least substantially equal.