Abstract: Materials, both glass and glass-ceramic, that exhibit UV-induced changes in light transmission and electrical conductivity behavior. The materials consist essentially, in mole %, of 20-40% SiO2, 10-20% AlO1.5, 35-55% SiO2+AlO1.5, at least 30% CdF2, 0-20% PbF2, and/or ZnF2, 0-15% rare earth metal fluoride, and 45-65% total metal fluorides.

Abstract: The present invention relates to a device for measuring a current in a magnetic field which includes a glass article wherein the glass may be an oxyfluoride glass or a bismuth oxide glass having a photoelastic coefficient of from about −0.2 to 0.2 at 546 nm. Further, the present invention relates to a method of measuring currents.

Abstract: A glass-ceramic rare earth doped fiber comprises a plurality of crystallites, wherein at least 90% of the rare earth dopant is situated within said crystallites. The stimulated emission and absorption line shapes of the rare earth doped glass-ceramic fiber is narrower than that stimulated emission and absorption line shapes of the precursor rare earth doped glass. This is indication of the reduction in the inhomogenous broadening of glass-ceramic fibers compared to glass fibers. An embodiment of an optical amplifier includes: an input port; a length of glass-ceramic rare earth doped fiber, the glass-ceramic fiber being operatively coupled to the input port and including a plurality of crystallites; at least one optical pump coupled to this glass-ceramic fiber; an output port providing an amplified optical signal; and at least one optical component situated between the input port and the output port.

Abstract: A method of determining the magnitude of an exceptionally large current which comprises measuring the angle of rotation of polarized light in a magnetic field created by the current with a glass fiber sensor composed of a fluoride glass having a low Verdet constant and a photoelastic coefficient not over about 0.25 (nm/cm)/(kg/cm2).

Abstract: Devices are made comprising a tin-phosphorous oxyfluoride glass, which has been exposed to light, preferably shorter in wavelength than the absorption edge of the glass, to change the refractive index change of the glass. The glasses can be used to form planar and fiber devices, including core/clad structures for guiding light.

Abstract: The present invention relates to a transparent glass-ceramic material which includes a glass matrix and a crystalline phase of lanthanum fluoride crystals in the glass matrix, where the transparent glass-ceramic material contains no silica. The present invention further relates to a method of producing the transparent glass-ceramic material.

Abstract: Materials, both glass and glass-ceramic, that exhibit UV-induced changes in light transmission and electrical conductivity behavior. The materials consist essentially, in mole %, of 20-40% SiO2, 10-20% AlO1.5, 35-55% SiO2+AlO1.5, at least 30% CdF2, 0-20% PbF2, and/or ZnF2, 0-15% rare earth metal fluoride, and 45-65% total metal fluorides.

Abstract: A method of determining the magnitude of an exceptionally large current which comprises measuring the angle of rotation of polarized light in a magnetic field created by the current with a glass fiber sensor composed of a fluoride glass having a low Verdet constant and a photoelastic coefficient not over about 0.25 (nm/cm)/(kg/cm2).

Abstract: Polymeric compositions having a polymeric component and an inorganic filler which undergoes a crystal (phase) inversion within the operating temperature range of the composition are provided. The present invention relates to a method for reducing the water sensitivity of particles of a crystallized phosphate glass. The particles are composed of P.sub.2 O.sub.5 and one or more cations selected from the group consisting of magnesium, cobalt, arsenic, zinc, iron, aluminum, and zirconium. The method includes nitriding the particles.

Abstract: The present invention relates to a method for packaging an optical waveguide coupler where the coupler includes a body having two end portions and a constricted portion located between the end portions. The method includes placing the coupler in a mold where the mold surrounds at least the constricted portion of the coupler, introducing a polymeric composition into the mold so that the polymeric composition substantially fills the constricted portion, curing the polymeric composition, and removing the mold.

Abstract: The present invention is directed to the preparation of two groups of transparent glass-ceramics exhibiting high optical clarity and containing essentially only one crystal phase. The first group consists essentially, in cation percent, of______________________________________ SiO.sub.2 20-35 PbF.sub.2 19-23 AlO.sub.1.5 10-20 YF.sub.3 3-7, CdF.sub.2 19-34 ______________________________________and the second group consists essentially, in cation percent, of ______________________________________ SiO.sub.2 20-35 PbF.sub.2 15-25 AlO.sub.1.5 10-20 YF.sub.3 3-7 CdF.sub.2 21-31 ZnF.sub.2 3-7. ______________________________________These glass-ceramics may be used to fabricate optical waveguide fibers. Also when doped with certain rare earth elements, notably Pr, Er, and Dy, the glass-ceramic materials may be used to fabricate optical amplifiers and lasers.

Abstract: The present invention is directed to the preparation of two groups of transparent glass-ceramics exhibiting high optical clarity and containing essentially only one crystal phase. The first group consists essentially, in cation percent, of______________________________________ SiO.sub.2 20-35 PbF.sub.2 19-23 AlO.sub.1.5 10-20 YF.sub.3 3-7, CdF.sub.2 19-34 ______________________________________and the second group consists essentially, in cation percent, of ______________________________________ SiO.sub.2 20-35 PbF.sub.2 15-25 AlO.sub.1.5 10-20 YF.sub.3 3-7 CdF.sub.2 21-31 ZnF.sub.2 3-7.

Abstract: Optical parts and optical equipment, including lenses, mirrors and laser media made of athermal glasses having compositions comprising 0-13 mol % CdO, 9-24 mol % CdF.sub.2, 5-10 mol % LiF, 30-34.5 mol % AlF.sub.3 28-33.5 mol % PbF.sub.2, 0-4 mol % KF, 0-6.5 mol % YF.sub.3, and 0-2 mol % LaF.sub.3 and having little or no optical path length change as a function of temperature in the infrared region of 1.mu.m to 5.mu.m.

Abstract: A method for foming glass articles of substantial thickness from unstable glass compositions which normally devitrify when formed by conventional casting or molding processes, is disclosed. The method includes the steps of quench-cooling the glass to form a crystal-free glass feedstock material, and then pressure-consolidating the feedstock at a temperature between the transition temperature and the crystallization temperature of the glass.

Abstract: Disclosed is a method of forming a glass preform from core and cladding glasses having low liquidus viscosities and narrow working ranges. A tube of liquid core glass is vertically situated in a vessel of liquid cladding glass. The tube extends to the bottom of the vessel where there is a stopper for preventing leakage of core glass. While both core and cladding glasses are at a temperature just above the liquidus temperature, the vessel is lowered into a coolant bath, thereby causing core glass to flow into the region vacated by the tube. The rate of withdrawing the tube from the vessel is sufficiently slow to provide laminar flow and yet fast enough to permit the resultant liquid core/clad composite to freeze before mixing occurs.

Abstract: Disclosed is a method and apparatus for drawing an elongated glass article such as a fiber optic device. The article is drawn upwardly from a source through the surface of a quantity of molten metal having a vertical temperature gradient. The source can be an elongated solid glass preform that is vertically positioned within the molten metal such that the temperature of that portion of the molten metal adjacent the upper end region is sufficiently high to heat that region to drawing temperature. The upper end region is pulled to form a tapered root, continued pulling resulting in the formation of an elongated article from the small diameter root end. The relative position of the root is maintained with respect to the surface of the molten metal during the drawing operation. Alternatively, the glass can be drawn from an orifice located within the molten metal.

Abstract: Mill additions are disclosed which lower the CTE of, and are compatible with, tin-phosphorus oxyfluoride glasses. The sealing materials provide fusion-type seals having a CTE not over about 110.times.10.sup.-7 /.degree.C. and a sealing temperature not over about 350.degree. C.Also disclosed is a family of glass compositions in the tin-phosphorus oxyfluoride system that exhibit very low glass transition temperatures and coefficients of thermal expansion not over about 160.times.10-7/.degree.C. (25.degree.-150.degree. C.). In addition to the four basic elements, the glasses contain up to 11% Nb, and may additionally contain up to 10%, taken individually or in combination, of V, Fe and/or Mo to further decrease the Tg and CTE values.

Abstract: An optical fiber transmission path wherein total dispersion of the system is compensated by use of fibers composed of glasses with total dispersion of opposite signs at the operating wavelength for the system. With silica-based fibers, CdF.sub.2 --LiF--AlF.sub.3 --PbF.sub.2 --KF--YF.sub.3 fluoride glass-based fibers may be used for a system with 1.55 .mu.m operating wavelength.

Abstract: Metal halide glasses of CdF.sub.2 -LiF-AlF.sub.3 -PbF.sub.2 composition but comprising KF and one or more of LaF.sub.3 and YF.sub.3 as stabilizers, and also including a minor amount of oxygen as a further stabilizer, exhibit excellent glass stability and low hydroxyl content as evidenced by high transmittance over the infrared wavelength range 2-6 microns.

Abstract: ThF.sub.4 --BeF.sub.2 glasses of specified composition exhibit sufficiently low high-temperature viscosity and melt stability to be useful for the fabrication of optical devices for ultraviolet or infrared light transmission. The low melt viscosity renders the glasses suitable as host materials for rare earth and transition metal dopants so that they can be used for optical devices such as lasers and optical filters.