Abstract: A device for coupling a pair of optical fibers is disclosed comprising a resiliently compressible body for holding a pair of opposing protectively jacketed fibers in end-to-end abutment within an oversized bore. The body is symmetrically compressed about its central portion to reduce the bore cross-section to a fiber-engaging dimension around the bare fiber tips thereby securely aligning the fibers. Similarly, the body is compressed about its end portions to decrease the bore cross-section to a jacket-clamping dimension whereby stresses in the spliced region are distributed along the fiber jacket.

Abstract: Narrow band wave guide reflectors arranged on a substrate and having wave guide layers with periodic perturbations are tuned by adapting the effective index of refraction n.sub.eff of the wave guide layer to fulfill the Bragg condition of reflection. The index of refraction is adapted by either varying the thickness of the wave guide layer continuously over a width of the layer or by applying a field to a substrate or superstrate comprised of magneto- or electro-optical material to change the index of refraction of the substrate or superstrate.

Abstract: The invention is directed to a security device which detects tampering with secured closure. A fiber optic bundle is looped through a closure and secured at opposite ends of the bundle to a collar. After installation, light is passed through the fiber optics and they generate a particular pattern at a viewing end of the collar. If there is any tampering with the enclosure, the individual fiber optics will be disturbed or cut. Subsequent viewing of the fiber optics will generate a different viewing pattern indicating that tampering has occurred.

Abstract: An optical fiber cable in which elongation under longitudinal tension is reduced by the use of a molecularly oriented plastic reinforcement member extending along the neutral axis of the cable.

Abstract: An optical waveguide in which intermodal coupling is deliberately induced. Perturbations are introduced along the waveguide. The perturbations have a spatial frequency that varies along the guide from f.sub.1 to f.sub.2, where f.sub.2 is .ltoreq. the critical frequency above which coupling to unguided modes occurs and f.sub.1 corresponds to the beat between the n.sup.th and the (n + 1).sup.th modes, the lowest modes of interest propagating in the guide.

Abstract: A reciprocal coupler for connecting anyone of a plurality of optical signal transmission lines to all the other transmission lines in an optical communication system.The coupler comprises an elongated transparent optical mixing rod optically coupled by a first endface to each of the waveguides forming the lines to be interconnected and by its second endface to both ends of return guides provided by a fiber bundle which form a loop.

Abstract: This invention relates to a method of aligning the core of a thin optical fiber with a light emitting optical device. Prior to alignment a thin, continuous high index of refraction layer is formed on a stripped end segment of the optical fiber. The layer is formed by applying a solution of a volatile solvent and high index of refraction polymer to the stripped segment and evaporating the solvent before beading of the polymer solution occurs. The core of the fiber can then be aligned with the light emitting optical device by observing light exit the optical fiber.

Abstract: Optical waveguides are fabricated by heating a region of a body of flat filter glass with an energy beam such as a scanning focused laser beam. The region is locally heated to a temperature at which softening occurs. Upon cooling two differing effects occur, the two effects causing a "W" shaped index of refraction profile. The first effect is the photoelastic effect due to the residual stress introduced as the heated material cools and contracts. The residual tensile stress is constant in the softened region, but decreases as the distance from the center of the heating increases. Since the density and therefore the refractive index of this region is inversely proportional to the residual stress, this effect resulted in a local refractive index minimum. The other effect is the material density change in the softened region. As the cooling rate is small in the center and large in the edge of this softened region, a density change occurs with the center attaining the highest value and decrease towards the edge.

Abstract: In an optical guide, for instance a flexible optical cable, comprising at least two optical fibres and, surrounding the fibres, an outer protective sheath, each of at least some of the optical fibres has a continuous coating of a metallic material, e.g. aluminium or an aluminium-based alloy, which reduces the risk of surface damage of the optical fibre and also serves as an optical screen. At least one covering layer of non-metallic protective material, e.g. resin, enamel or plastics material, may overlie the metallic coating of each metal-coated optical fibre.

Abstract: An optical switch affords the selective coupling of any of a plurality of input light signals to any of a plurality of optical output paths. A first plurality of ports circumferentially disposed in a first common plane supports means for transmitting and/or receiving optical signals. A second plurality of ports similarly circumferentially disposed in a second common plane having the same central axis as the first common plane, supports means for transmitting and/or receiving optical signals. A rotatable assembly is mounted on a common support structure with the input and output ports and has first and second members which are independently movable about the central axis.

Abstract: The dispersion of optical signals derived from a spontaneous emitter when coupled into an optical fiber waveguide is substantially reduced by optically coupling a narrow band pass interference filter between the emitter and waveguide. Only a narrow portion of the broad spectral width emission of the emitter is thereby coupled into the waveguide to provide emitter modulation rates limited only by the rise-time of the emitter. In the preferred embodiment, the coupled spectral portion corresponds to the wavelengths of peak emission. Additionally, the filter is a thin film filter deposited onto either the light-exiting face of the emitter or onto the light-receiving end of the fiber waveguide.

Abstract: The present invention is concerned with an imaging system for the self-imaging of objects, using optical waveguides comprising reflecting boundary surfaces, and satisfying the imaging condition L.lambda. = 4hN.sub..mu. W.sup.2.sub.eq, wherein L is the axial distance between the object and the self-image, W.sub.eg is a typical transverse dimension of the waveguide having an effective refractive index N.sub..mu., and .lambda. is the operational wavelength, and h is an integer for single imaging and not an integer for multiple imaging.Many embodiments of dielectric thin film waveguides are described which have the purpose of self-imaging very small objects with good levels of resolution. Magnification or reduction by means of the imaging system are also provided for.

Abstract: A connector for coupling a pair of single optical fibers is disclosed. Each contact of the connector utilizes three spheres of equal diameter defining a tricuspid interstitial space therebetween into which the end of a fiber is mounted. The spheres are embraced by a circular race. In the preferred embodiment, the spheres engage each other and the race. When a pair of contacts are mated in axial abutting relationship, the spheres in the mating contacts nest with respect to each other, thereby precisely laterally aligning the optical fibers which are mounted in the interstitial spaces of the sets of spheres in the two contacts. In another embodiment, the spheres are dimensioned so they do not engage each other, but engage the optical fiber at three points. Also, more than three spheres may be mounted in a contact for positioning a fiber therein.

Abstract: A thin optical waveguide is formed by a waveguide region having an index of refraction greater than the index of refraction of the substrate. The greater index of refraction of the waveguide region is a result of residual stress within the waveguide region.

Abstract: An optical fiber junction device for permanently coupling a pair of optical fibers with a third optical fiber. The end portions of the pair of fibers are fused together in side-by-side relationship so that their endfaces are coplanar, the cross-sectional area of this structure decreasing toward the endfaces of the pair of fibers. The endface of the third fiber is fused to the endfaces of the pair of fibers.

Abstract: A process for producing an optical transmission fiber is provided which comprises feeding highly pure halides, hydrides or organic compounds of Si and B by way of carrier gas on the outer surface of a fused silica rod or a fused silica pipe, or inner surface of a fused silica pipe, oxidizing them and depositing the products to form a pure fused silica layer or a doped fused silica layer containing B.sub.2 O.sub.3, melting the pipe and the deposited layer followed by a spinning. The SiO.sub.2 layer can alternatively contain fluorine instead of B.sub.2 O.sub.3. A further SiO.sub.2 layer can be deposited thereon to improve the spinning processability and lower the index of refraction of the B.sub.2 O.sub.3 containing layer.

Abstract: A solid state apparatus for and a method of (1) coupling a light beam to a dielectric waveguide, (2) modulating the intensity of the coupled, diffracted light beam, and (3) multiplexing the coupled, diffracted light beam within the waveguide to any one of several detectors. The apparatus uses a liquid-phase epitaxially (LPE) grown film of bismuth substituted rare earth iron garnet to form a magnetizable layer in which stripe domains may be generated, sustained and moved about. The stripe domains from a diffraction grating, the stripe domain width and orientation of which may be altered by the application of external magnetic fields--see the E. J. Torok, et al., U.S. Pat. No. 3,752,563. The altered stripe domains are, in turn, utilized to alter the coupling of the light beam to the waveguide and to alter the direction that the coupled, diffracted light beam is directed within the waveguide.

Abstract: A non-metallic, high strength, high temperature resistant external or internal strengthening for fiber optics cables is provided. The strengthening may be in various forms such as internally deployed filaments, outer woven mesh fibers, segmented cylinders, helical wrap ribbon, etc., and is made from single high-strength crystal fibers preferably of sapphire, i.e. .alpha.-Al.sub.2 O.sub.3. The non-conductive strengthening crystals have a low density, are highly crush resistant and meet severe environmental fiber optic sensor and data transmission requirements.

Abstract: First and second diffraction gratings have a common fundamental spatial frequency. A coupling assembly is formed by connecting the gratings together with bars of the first grating at an angle of approximately 10.sup.-3 radians to bars of the second grating. The coupling assembly is mounted upon a waveguide carried by a substrate. A fiber is moved to a multiplicity of locations on the coupling assembly while light is transmitted through the waveguide. The fiber is fixedly connected to the coupling assembly at a location where there is a maximum amount of the light coupled from the waveguide to the fiber, whereby the fiber and the substrate form a sandwich that includes the coupling assembly and the waveguide. An etching process is used to remove parts of the coupling assembly that are not within the sandwich.

Abstract: The end of an optic signal conduit has a generally cylindrical, electrically conducting ferrule, which also engages the end of an electric power conduit. A circuit board contains electrical circuitry to be powered from said electric power conduit and optic signal receiving means for controlling said circuitry. An electrically conducting, hollow, generally tubular receptor on the circuit board has an integral extending tab for connection to the board and to the electrical apparatus thereon and receives the ferrule axially therein, in physical and electrical contact therewith and in alignment with the optic signal receiving means.