Abstract: A semiconductor laser diode array including a plurality of laser diode bars, each carried by a submount and forming a subassembly. Each subassembly is separated by a flexible or compliant electrically conductive spacer. All connections within the array are by way of a non-fluxed solder, that may be hard and/or soft, reflowed in a non-oxidizing atmosphere in a simple mechanical stack fixture to create nearly void-free solder joints with relatively high thermal integrity and electrical conductivity. Flexible electrically conductive spacers are disposed between the subassemblies to eliminate tensile stress on the laser diode bars while providing electrical conductivity between subassemblies. The subassemblies are carried by a thermally conductive dielectric substrate, allowing waste heat generated from the bars to be conducted to a cooling device. The invention eliminates known failure modes in interconnections, minimizing tensile strength on the diode arrays, and increasing the useful life of the array.

Abstract: A semiconductor laser diode array including a plurality of laser diode bars, each carried by a submount and forming a subassembly. Each subassembly is separated by a flexible or compliant electrically conductive spacer. All connections within the array are by way of a non-fluxed solder, that may be hard and/or soft, reflowed in a non-oxidizing atmosphere in a simple mechanical stack fixture to create nearly void-free solder joints with relatively high thermal integrity and electrical conductivity. Flexible electrically conductive spacers are disposed between the subassemblies to eliminate tensile stress on the laser diode bars while providing electrical conductivity between subassemblies. The subassemblies are carried by a thermally conductive dielectric substrate, allowing waste heat generated from the bars to be conducted to a cooling device. The invention eliminates known failure modes in interconnections, minimizing tensile strength on the diode arrays, and increasing the useful life of the array.

Abstract: An X-ray collimator grid is formed within a wafer of monocrystalline silicon material by forming a plurality of spaced parallel elongate slots within a planar surface of a silicon crystal wafer, and forming slats of heavy metal in situs within each of said slots, including squeegeeing the heavy metal into the slots, from particles of heavy metal, each said slat gripping the walls of an associated slot.

Abstract: A durable, broad-band low insertion loss RF feedthrough is formed of a straight conductor (5) centrally supported by, hermetically sealed to and axially extending through the center of a strong, rigid, impervious ceramic disk (3). The ceramic disk is hermetically sealed, directly or indirectly, to the metal barrier (11) through which the feedthrough is to propagate RF energy. The new ferrule and ferrule-less ceramic metal RF feedthroughs avoid the use of glass, conventional in existing feedthroughs. The novel feedthrough serves as the principal element of a microwave microstrip line to waveguide transition.

Abstract: A hybrid package in which Kovar feedthroughs are friction welded to an aluminum housing. Friction welding produces a very strong weld joint which resists the thermal stresses induced between the aluminum housing and Kovar feedthroughs by the large difference in their coefficients of thermal expansion. Friction welding also produces a very small heat affected zone, while brazing, soldering and other types of welding produce large heat affected zones which can cause annealing problems. The aluminum package is easy to machine, light in weight and provides good heat dissipation for the hybrid microcircuits in the package.

Abstract: A method is disclosed for effecting electronic article surveillance with a first high frequency signal and a second lower frequency signal, the second signal having a modulation characteristic therewith. Generally rectangular tag devices are attached to said articles for receipt of such signals and for reradiation thereof.

Abstract: An improved receptor-reradiator, for use in a surveillance system employing a carrier frequency of UHF or higher in combination with a low frequency electrostatic field signal to be modulated on the carrier signal by the reradiator, is provided by an antenna frame wherein the metallic foil of which it is made is divided into three parts. The first part is U-shape of substantially one width and joins to a central portion of substantially reduced width which is predominantly inductive at the carrier frequency. A semiconductor diode, preferably a Schottky barrier diode or PIN switching diode, is connected in said central portion in series therewith. The opposite end of the central portion joins to an enlarged rectangular portion. At the low frequency the component has effectively two capacitive arms, one on each side of the diode, of different surface area to ensure bias signal for the diode.

Abstract: A low current electrostatic generator powers an electrode that, when proximate to the non-conductive outer surface of a surveillance tag, causes an electrostatic discharge to pass through such outer surface from the electrode and to be received by a conductive circuit within the tag. The resulting discharge impressed across the conductive circuit passes through a diode semiconductor included within such circuit to destroy the diode's unidirectional conducting characteristic and thereby deactivate the tag. No exposed conductive terminals are required on the outer surface of the surveillance tag, and the probe need not physically contact the tag to deactivate it.

Abstract: A surveillance marker has a semiconductor connected between arms of a dipole antenna, one arm being of non-ferrous conductive material and the other of high permeability low coercivity material such as permalloy. Higher coercivity magnetizable pieces are disposed adjacent the low coercivity arm, and all is sandwiched between paper or other insulating layers. The marker is detected by a combination of RF field and low frequency magnetic field generating and receiving units that energize a master alarm only when both units simultaneously detect the marker signals. Magnetizing the higher coercivity pieces suppresses a signal that would otherwise be reradiated by the marker from the high permeability arm thereby rendering the marker undetectable.