Abstract: Multi-period structures exhibiting giant magnetoresistance (GMR) are described in which the exchange coupling across the active interfaces of the structure is ferromagnetic.

Abstract: Multi-period structures exhibiting giant magnetoresistance (GMR) are described in which the exchange coupling across the active interfaces of the structure is ferromagnetic.

Abstract: An optical bypass switch receives arbitrarily polarized light from an input optical fiber which is divided into the P and S-polarized light beams by a polarization beamsplitter. These P and S-polarized light beams are focussed to a magneto-optic garnet wherein the plane of polarization is rotated in accordance with a desired switching function and directed to an output optical fiber determined by the polarization rotation state established in the magneto-optic garnet.

Abstract: An optical bypass switch includes a variable diffraction element responsive to acoustical signals operable to couple light signals incident to first and second input ports to first and second output ports, respectively, for a first diffraction index and from the first and second input ports to the second and first output ports, respectively, for a second diffraction index. Acoustical signals are provided by an electro-acoustic transducer coupled to the variable diffraction element which establishes acoustical signals in response to acoustical signals coupled thereto.

Abstract: A thin, nominally 150 angstroms, normal metal layer, nominally the noble normal metal palladium, sandwiched intermediate between two superconducting layers, nominally niobium, supports totally superconducting current flow therethrough such normal metal layer by the quantum mechanical tunneling effect. Such a thin normal metal layer is useful as a stop etch layer for fabrication process control, including especially the selective niobium anodization process, as an oxidation resistant or immune layer to which totally superconducting electrical contact may be reliably made such as by soldering, and as a patterned resistor in those regions of the substrate plane where such thin normal metal layer is not sandwiched by superconducting layers. Particularly concerning such stop etch function, a thin normal layer of palladium will serve as a stop etch layer to the etching of niobium while not precluding totally superconducting contact therethrough such thin palladium layer.

Abstract: A type of Superconducting Quantum Interference Device (SQUID) requires that relatively large, circular, toroidally wound wire coils within a first cavity of a superconducting canister should be inductively coupled to a relatively small SQUID created as an annular ring plus Josephson junctions upon a substrate within a second cavity of the superconducting canister. The required inductive coupling is through a dielectric filled cavity called a coupling cavity which is conical in the shape of a dunce's cap. The conically shaped coupling cavity within the superconducting canister minimizes the parasitic stray inductance which is coupled to the SQUID, and thusly improves the noise performance of the SQUID.

Abstract: A display system using the dispersive Faraday coefficient of a magnetic screen to obtain a color display from white light is disclosed. A beam of energy is directed upon a magnetic screen while concurrently an intensity modulated magnetic field is directed normal to the surface of the magnetic screen. The combination of the heating effect of the energy beam and the magnetic orienting effect of the intensity modulated magnetic field established localized areas of differing magnetic characteristics over the planar surface of the magnetic screen. Subsequently, a polarized beam of white light that floods the magnetic screen is, for each of several wave lengths, differently rotated upon passing through each of the areas of differing magnetic characteristics in the magnetic screen. The beamlets that are formed by the so-differently rotated areas of the polarized white light beam are then passed through an uncrossed analyzer, which beamlets appear as a multicolored projection upon the magnetic screen.

Abstract: A display system for providing a real-time, dynamic presentation of an analog signal waveform is disclosed. The system includes an A-D converter that, in turn, drives a serial string of binary weighted bubble domain generators. The bubble domain generators generate moving columns of bubble domains, the total amplitude of light that is provided by each column representing the amplitude of the analog signal waveform at each of an associated sample time. The bubble domain memory plane is of a construction to permit the columns of moving bubbles to appear as moving columns of bright spots when seen by an observer using a plane polarized light beam and an analyzer.

Abstract: A system for optically correlating two signals, e.g., radar, sonar, etc., incorporating both time shifts and doppler shifts is described. The correlation of the signals is produced as a two-dimensional distribution of light on a light detector/display plane wherein the amplitude of the light distribution is proportional to the correlation of the two signals as a function of relative time shifts, .DELTA.t (X direction), and relative doppler shifts, .alpha..omega. (Y direction), between the signals. Doppler shifts are introduced into the processor by the incorporation of a channelized cylindrical lens in one signal channel while using a cylindrical lens in the other signal channel.