Abstract: The exterior surfaces of a laser rod and pump lamp are covered with a highly reflective metal foil to prevent light leakage from the rod and lamp. The laser rod and pump lamp operate within a cavity inside a heat sink. Between the metal foil and the housing is a thermally conductive fluidic material selected to provide a tailored thermal impedance between the heat sink and the rod and pump to optimize the steady state temperatures of these components. The conductive fluid is not circulated but is contained to act as a simple heat conductor. The optically reflective and the heat transfer functions of the laser pumping operation are essentially separate from each other, enabling selection of materials for these respective functions to enhance performance of the laser and substantially simplify its construction.

Abstract: Drift of the standing wave pattern in an acoustic doppler intrusion detection system with radiating and receiving transducers in a confined space is compensated by changing the operating frequency of the carrier wave generator when the magnitude of the received carrier wave is less than a predetermined threshold level. The magnitude of the received carrier wave is continuously monitored and compared to the threshold level. The generator frequency is incrementally increased until the carrier wave magnitude is optimum. This invention comprehends the apparatus for and method of optimizing signal strength at the receiving transducer by this technique.

Abstract: A type of electrochemical cell has elements wound in a coil and inserted in a sealed can. One element has a metal substrate carrying a plurality of holes. The metal substrate supports layers of an electrode material such as porous carbon. Both edges and one end of the substrate is kept free of the material. The bare end of the substrate is on the outside of the coil. The substrate is wider than other elements of the coil, so that when the coil is inserted in the can, the substrate makes contact with all the internal surfaces of the can.

Abstract: A type of electrochemical cell has two electrode structure elements wound in a coil and inserted in a sealed can. The electrode structures are separated by a porous insulating sheet. One electrode structure has a metal substrate carrying a plurality of holes. The metal substrate supports layers of an electrode material such as porous carbon. Both edges and one end of the substrate is kept free of the material. The bare end of the substrate is on the outside of the coil. The substrate and porous insulating sheets are wider than the other electrode structures, so that when the coil is inserted in the can, the substrate and the porous insulating sheet makes contact with the top and bottom internal surfaces of the can.

Abstract: Trichlorotrifluoromethane is used as a vehicle to apply carbon and a binder to a substrate. Carbon black and tetrafluoroethylene are suspended in liquid trichlorotrifluoroethane to form a slurry. A layer of the slurry is deposited on a substrate. The trichlorofluoromethane is evaporated leaving a porous residue of carbon and tetrafluoroethylene on the substrate.

Abstract: Laser apparatus having a very narrow (<1A) spectral output comprises a laser cavity having a metal vapor cell as one of the reflecting elements. This cell reflects the laser beam over a narrow wavelength region in the vicinity of one of the metal vapor's resonant absorption lines and achieves frequency locking to an atomic resonance line without any external frequency sensors or feedback loops.

Abstract: Electrochemical cell having a battery stack of an electrode assembly wound on a spool. The electrode assembly includes two elongated electrode structures, an anode electrode structure and a cathode current collector structure. The spool has a central post of insulating material and two conductive flanges. The two electrode structures are wound around the post with insulating material between them, the anode electrode structure making contact with one of the flanges and the cathode current collector structure making contact with the other flange.

Abstract: An electrode assembly adaptor to be wound on a spool to provide a battery stack for an electrochemical cell. The spool has a central post of insulating material and two conductive flanges. The electrode assembly includes two elongated electrode structures, an anode electrode structure and a cathode current collector electrode structure. Each electrode structure includes a metal substrate having deflective, resilient contact tabs spaced along one edge. An appropriate electrode material is adherent to the substrate. The electrode assembly of the two electrode structures with intervening insulating material is adapted to be wound around the post of the spool with the contact tabs of the anode electrode structure making contact with one of the flanges and with the contact tabs of the cathode current collector electrode structure making contact with the other flange.

Abstract: Electrochemical cell having at least two battery stacks each including an electrode assembly wound on a spool. Each electrode assembly includes two elongated electrode structures, an anode electrode structure and a cathode current collector structure. The electrode structures are wound around the center post of the spool with the anode electrode structure making contact with one of the conductive flanges of the spool and the cathode current collector structure making electrical contact with the other conductive flange of the spool. The flanges in contact with the anode structures of the battery stacks are connected to one external terminal of the cell, and the flanges in contact with the cathode current collector structures of the battery stacks are connected to another external terminal of the cell.

Abstract: A pulsed or CW laser is rapidly switched to operate at one or more selectable wavelengths by means of intracavity insertion of beam dispersion and focussing elements and an apertured focal plane mask and shutter assembly. The laser beam has an axis and is dispersed into components or sub-beams having different axes and representing different wavelengths, the sub-beams being focussed to substantially reduced diameters on the focal plane mask at points, respectively, at which apertures are formed. Movable shutters adjacent to the respective apertures control alternate opening of and closing of the apertures and selectively permit the laser to resonate at at least one of a plurality of wavelengths corresponding to that of the sub-beam passing through an open aperture. Mask apertures having very small diameters (<50 microns) and separations are achieved enabling switching between different operating wavelengths in milliseconds.