Abstract: A radial flow ring laser having an unstable resonator configuration with a traveling wave optical path is disclosed. The gain medium forms a cylindrical sheath which is symmetric about a centerline axis through the resonator and the output beam is circular in cross section. The resonator geometry is based on first and second conical mirrors which are positioned symmetrically on the axis centerline and first and second annular mirrors which are symmetric about the axis and complete the ring path. The resonator description also includes an annular stripper mirror to produce the output beam of radiation and a suppression mirror to prevent a traveling wave in the undesired direction through the ring. An alternate embodiment includes a cylindrical folding mirror to cause the optical path to cross the centerline axis after each pass through the gain medium.

Abstract: Method and apparatus for providing a large fraction of the energy coupling from an unstable resonator in the central lobe of the far field pattern of the output beam from the resonator are disclosed. The resonator is designed to allow a low order mode pattern to resonate about the optical axis therethrough and radiation is coupled out from both the axial region and the outer region of the mode. The geometry of the systems is formed with transmissive and reflective optics in various configurations of linear and ring lasers.

Abstract: A chain reaction laser system which operates with two species lasing simultaneously is disclosed. The laser is combustion-driven and provides an output of continuous wave radiation. A fluorine interhalogen and atomic fluorine are mixed together with hydrogen to induce chemical reactions which provide two species of hydrogen halides which are vibrationally excited as well as atomic hydrogen and atomic fluorine. The latter, atomic fluorine, is then available to react with additional hydrogen in a chain reaction sequence. The various preferred reactants and two preferred structures are discussed. In a first embodiment the fluorine interhalogen and atomic fluorine which are both essential to the operation of the invention are both formed as they are needed in a reaction region at relatively high temperature and pressure. In a second embodiment one reactant is formed under conditions of relatively high temperature and pressure and the other at low temperature and pressure conditions.

Abstract: A new resonator concept which is especially useful in chemical laser applications is disclosed. A ring end mirror, a conical folding mirror and a circular end mirror are combined to form an unstable resonator including a radial direction propagation having a gain medium region and a region of axial direction propagation. Alternate embodiments of the invention include the use of nonreflective fins in the region containing the working medium to suppress superfluorescence and an aerodynamic window to keep depleted working medium out of the path of the resonant beam.

Abstract: Disclosed is a technique for producing vapors of metals in containment vessels that experience the melting temperature but not the boiling temperature of the metal being vaporized. The metal is maintained in molten pools by the containment vessel. Pumping means such as wicks transfer the metal from the pools to a higher temperature region internal of the containment vessel where the liquid metal is boiled into a vapor. The generation of laser radiation from an excited metal vapor produced in this manner is also disclosed.

Abstract: An enclosure designed to maintain the purity and physical characteristics of a slurry within a preferred range during the manufacture of shell molds is disclosed. The tank is in the form of a trough with flat side walls and a curved member forming the front, bottom and back of the trough. The entire trough is water cooled and a cover along the top completes the enclosure. The enclosure is fitted with means for circulating the slurry and a liner having an airfoil member. Various sensing and control means are interconnected through a feedback system which continuously monitors and controls the conditions of the slurry.