Abstract: The optical fiber element comprises at least one layer of coating constituted by a polyacrylate reticulated by UV radiation and at least one H.sub.2 -absorbing buffer, said polyacrylate comprising at least one photo-initiator of UV reticulation possibly together with an activator for it wherein said photo-initiator and its activator, if any, are selected from the group which comprises those photo-initiators and those activators which cause a reduction in the hydrogen absorption capacity of less than 30% in a H.sub.2 -absorbing buffer which has been in contact with said polyacrylate containing them for 30 days at 100.degree. C. in an air atmosphere saturated with water vapor at 150 mbar.

Abstract: A scintillating article comprising a substrate coated with an inorganic scintillating material comprising a doped or undoped material selected from the group consissting of barium fluoride, calcium fluoride, zinc oxide, zinc sulfide, zinc silicate, bismuth germanate, fast cathode ray tube phosphors, yttrium silicate, rare earth silicates, orthosilicates, and mixtures thereof. Also disclosed is an appertaining method of forming such a scintillating article, comprising depositing the inorganic scintillating material by chemical vapor deposition (CVD). In a particularly advantageous embodiment, the substrate is of fibrous form, e.g., a quartz optical quality fiber, which is coated with a scintillating material such as barium fluoride.

Abstract: An apparatus and method for detecting a chemical substance by exposing an optic fiber having a core and a cladding to the chemical substance so that the chemical substance can be adsorbed onto the surface of the cladding. The optic fiber is coiled inside a container having a pair of valves for controlling the entrance and exit of the substance. Light from a light source is received by one end of the optic fiber, preferably external to the container, and carried by the core of the fiber. Adsorbed substance changes the transmissivity of the fiber as measured by a spectrophotometer at the other end, also preferably external to the container. Hydrogen is detected by the absorption of infrared light carried by an optic fiber with a silica cladding. Since the adsorption is reversible, a sensor according to the present invention can be used repeatedly.

Abstract: This invention is drawn to heavy metal oxide glasses exhibiting high nonlinear susceptibility and infrared transmission consisting essentially, in weight percent, of 42-48% PbO, 33-44% Bi.sub.2 O.sub.3, 10-15% Ga.sub.2 O.sub.3, and up to 15% total of at least one member of the group consisting of up to 5% SiO.sub.2 and/or GeO.sub.2 and up to 15% Tl.sub.2 O. This invention also comprehends the fabrication of light guiding fibers from those glasses.

Abstract: An optical waveguide fiber with a fatigue resistant TiO.sub.2 -SiO.sub.2 outer cladding including a cylindrical outermost layer with TiO.sub.2 concentration greater than 10.5 wt. % and thickness less than 3 .mu.m. The fiber may include a two layer outer cladding with higher TiO.sub.2 concentration in the outer layer. The outer cladding may include a plurality of inhomogeneities dispersed in a TiO.sub.2 -SiO.sub.2 matrix.

Abstract: A plastic optical fiber comprising a core and a clad, said core being formed by an amorphous and optically transparent polymer and said clad being formed by a polymer having a refractive index lower than that of the core by at least 0.3%, at least one of the core and the clad being formed by an amorphous and optically transparent polymer containing metal elements and halogen atoms, is low in light loss and excellent in heat resistance.

Abstract: An optical transmitting system comprising a light source, an optical transmitting portion from the light source, and an optical detecting portion characterized in that a fraction of deuterium substitution for hydrogen in a repeat unit of an organic polymer composing the optical transmitting portion is at most 40%, fluorine content in said organic polymer is less than 40% by weight, and said organic polymer comprises an amorphous polymer which satisfies the equation (I):(.rho./M)(9.1.times.10.sup.-5.n.sub.CH +9.1.times.10.sup.-4.n.sub.NH +1.5.times.10.sup.-3.n.sub.OH)<5.3.times.10.sup.-6 (I)[where, .rho. is density of the polymer (g/cm.sup.3), M is molecular weight of the repeat unit (g/mol), n.sub.CH, n.sub.NH, and n.sub.OH indicates number of combination of C--H bond, N--H bond, and O--H bond in the repeat unit respectively].

Abstract: Melt-processible copolymers of at least two halogenated comonomers from a defined class, especially perhalogenated comonomers, and particularly perfluorinated comonomers, of improved thermal stability are obtained by first contacting the copolymers with a stabilizing agent selected from bases (ammonia or amines) having a boiling point at normal pressure of at most 130.degree. C. and tertiary alcohols having up to 8 carbon atoms, to form an intermediate, drying the intermediate at about 70.degree.-150.degree. C., and fluorinating the intermediate at a temperature between 20.degree. C. and the lowest temperature at which the copolymer exhibits a solid state transistion, then removing excess fluorine and by-products and recovering the stabilized copolymer. Such stabilized copolymers are useful for a variety of technically important applications, including as cladding for optical fibers, substrates for electronic components, thermal laminates, pipes, tubes, and fittings, etc.

Abstract: An image fiber preform for use in an image fiber according to the present invention includes a plurality of optical fiber strands, each optical fiber strand including a silica glass core which contains a dopant for increasing a refractive index of the core and a silica glass cladding surrounding the silica glass core, the silica glass cladding containing a fluorine dopant for decreasing a refractive index of the cladding, the cladding having an outer peripheral surface, and a quartz tube in which the optical fibers are closely arranged, wherein the cladding has a concentration of the fluorine dopant which decreases radially outward toward the outer peripheral surface of the cladding. in the present invention, an image fiber prepared from the image fiber preform and fabrication processes for the image fiber preform and the image fiber are provided.

Abstract: A fiber optic coupler of the type wherein first and second single-mode optical fibers, each having a core and a cladding, are fused together along a portion of the lengths thereof to form a coupling region. The fiber diameters are smaller in the coupling region than in the remainder of the fibers. The cladding of the second fiber contains an amount of chlorine sufficient to increase the refractive index n.sub.2 ' thereof to a value greater than the refractive index n.sub.2 of the cladding of the first fiber.

Abstract: Methods and apparatus are shown for cladding grown single crystal optical fibers. Neodymium YAG fibers are clad with a high index glass, either melted around the fiber in a trough or extruded over the fiber surface. Lithium niobate fibers are clad through an impregnation process. The lithium niobate fiber is first coated with magnesium oxide and then heated to a temperature and for a time sufficient for the magnesium oxide dopant material to diffuse into the fiber. The dopant lowers the intrinsic refractive indices of the fiber material around its circumference, creating a cladding region around the fiber core. Single crystal fibers clad by these methods and combined with suitable pumping means or with deposited electrodes provide low-loss single mode optical components useful for amplification, electro-optical effects and acousto-optical effects.