Abstract: Said medium is a halide glass (2, 8, 12, 20) containing uranium ions at least partly in the form U.sup.3+ and having, at least at one point of a region of the near infrared between 2.2 and 3.4 micrometers, an optical attenuation not exceeding 0.01 cm.sup.-1. For the production thereof, preparation takes place of a halide glass containing uranium ions, at least partly in the form U.sup.4+ and/or U.sup.5+, and having at least at this point the aforementioned attenuation. The glass is exposed to ionizing radiation able to produce trivalent uranium ions from the uranium ions of the prepared glass. Application to the production of optical guides, whereof the guiding parts are formed from such a medium.

Abstract: An optical fiber having a core with a composition consisting essentially of 48 to 60 mole percent ZrF.sub.4, 15 to 25 mole percent BaF.sub.2, 1 to 5 mole percent LaF.sub.3, 1 to 5 mole percent AlF.sub.3, 15 to 22 mole percent NaF, and 1 to 8 mole percent ThF.sub.4 ; and a cladding having an index of refraction lower than that of the core. The glass of the core can be doped, for example, with rare earths. Built-in casting, rotational casting, casting around a rod, and rod-in-tube methods can be used to produce optical fibers having a composition in accordance with the present invention and having improved resistance to crystallization, as compared to ZBLAN glasses, even in the presence of rare earth dopants.

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: An optical functioning glass for enabling optical amplification at 1.3-.mu.m wavelength band or increasing efficiency of the amplification is disclosed. The optical functioning glass contains Nd.sup.3+ as an active material and uranium, both of which are doped in a multi-component function glass serving as a host glass. Since uranium is doped in the optical functioning glass, light emission of Nd.sup.3+ in the 1.06-.mu.m wavelength band can be absorbed by uranium. A decrease in efficiency of induced emission in a 1.3-.mu.m wavelength band can be prevented, and an optical functioning glass suitable for optical amplification in the 1.3-.mu.m wavelength band can be obtained. When a fiber is formed using the optical functioning glass as a core, a low-threshold, high-gain fiber amplifier, fiber laser, and the like can be obtained.

Abstract: This invention is directed to the production of transparent glasses exhibiting transmission far into the infrared regime of the radiation spectrum. The glasses consist essentially, in mole percent, of 42-55% CdF.sub.2 and/or CdCl.sub.2, 2-15% BaF.sub.2 and/or BaCl.sub.2, 30-40% NaF and/or NaCl, 2-7% KF and/or KCl, 1-12% total of at least one stabilizing metal halide selected from the group LiX, BeX.sub.2, MgX.sub.2, MnX.sub.2, PbX.sub.2, TlX, CoX.sub.2, and ZnX.sub.2, and 0.005-0.5% ReX.sub.3, wherein Re is at least one rare earth metal selected from the lanthanide series of rare earth metals and X is at least one halide selected from the group consisting of fluoride, chloride, and bromide.

Abstract: The method involves producing a multi-component glass doped with CdS.sub.x Se.sub.y Te.sub.z microparticles. The process has solved the conventional problems that the chalcogen element(s) to constitute the microparticles is (are) vaporized at the step for obtaining a glass melt, by specifying (a) the material to become a glass matrix and (b) the atmosphere used for obtaining a glass melt. The method involves using a mixture of elemental Cd and at least one of the elements S, Se and Te.

Abstract: The present invention relates to a matrix glass composition for glass doped with dispersed CdS.sub.x Se.sub.y Te.sub.z (x+y+z=1) microcrystallites, which contains P.sub.2 O.sub.5 and/or B.sub.2 O.sub.3, and ZnO and/or CdO as essential constituent components, in which the total amount of P.sub.2 O.sub.5 and B.sub.2 O.sub.3 is in a range of from 35 to 65 mol %, and the total amount of ZnO and CdO is in a range of from 65 to 25 mol %. The present invention relates also to glass doped with dispersed microcrystallites which comprises a matrix glass composition as defined above as matrix glass, and CdS.sub.x Se.sub.y Te.sub.z (x+y+z=1) microcrystallites precipitated in the matrix glass.

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: A multi-component glass doped with microparticles of CdS.sub.x Se.sub.y Te.sub.z, which can be used as a material for sharp cut filter, a material for infrared-transmitting filter or a nonlinear optical material. This glass has solved the problems of conventional glasses doped with microparticles, of (a) being low in microparticles concentration and accordingly having a low spectral characteristic when made into a thin filter and (b) being low in microparticles concentration and accordingly having low third-order nonlinearity, by containing microparticles at a high concentration, i.e. 5-50% by weight. The present invention relates to a process for producing the above multi-component glass doped with CdS.sub.x Se.sub.y Te.sub.z microparticles.

Abstract: The semiconductor-containing glass disclosed herein is a semiconductor-containing glass which is produced by a sol-gel technique and which includes a semiconductor-containing glass characterized in the composition of a glass matrix and a semiconductor-containing glass characterized in the composition of a semiconductor. Either a semiconductor-containing glass has useful properties as a non-linear optical material.The method of producing semiconductor-containing glass disclosed herein is a method in which oxidization, volatilization or decomposition of a compound semiconductor or volatilization of a constituent element of the compound semiconductor by heat treatment for forming glass from a gel solid can be suppressed when a semiconductor-containing glass in which the compound semiconductor is dispersively precipitated is produced by a sol-gel technique.

Abstract: Crystallization-resistant, low liquidus, fluoride glasses are disclosed which consist essentially of ZrF.sub.4, optionally HfF.sub.4, BaF.sub.2, at least one of CsF or NaF, preferably AlF.sub.3 and LaF.sub.3, and at least one of InF.sub.3, YF.sub.3 and GaF.sub.3. The glasses are of utility as optical components because of their high IR transmission.

Abstract: Defect-free fluoride glass materials are made by hot isostatic pressing (HIP) of a fluoride glass. The process may be used to manufacture preforms or bulk fluoride glass. The external pressure applied during HIP squeezes bubbles from the glass and permits the use of a wider range of working temperatures than ordinarily available, thereby reducing crystallization defects.

Abstract: Discrete, free-flowing, ceramic microbubbles consist essentially of at least one of a non-oxide component and an oxide component having diameters in the range of 1 to 300 micrometers and each having a wall thickness of less than 10 percent of the diameter of the bubble. In the process of the invention, a sol precursor and a suitable liquid, referred to as a bloating agent, when added to a bubble promoting medium under proper conditions, provide green gelled microbubbles which after firing are ceramic microbubbles having wall thicknesses less than 10 percent of the diameter of the bubbles. The microbubbles are non-vitreous, sol-gel derived, fine microstructured, uniform, hollow, smooth, and are either essentially all oxide or non-oxide or combinations of both.

Abstract: A crystal of a composition of silver, thallium, and sulfur is useful in non-linear optical devices, acousto-optical devices, piezo electric devices and other types of optical and acoustic devices. The chalcogenide glass composition of the invention displays superior transmission beyond 12 .mu.m.

Abstract: Discharge tubes formed of metal fluoride gases are used in apparatus for emitting high frequency laser and fluorescent light. The discharge tubes are resistant to corrosion from halogen-containing gas mixtures subjected to high frequency excitation in the apparatus.

Abstract: Disclosed in a cement composition comprising an unsaturated carboxylic acid polymer and an alkaline earth metal aluminofluorosilicate glass, wherein the alkaline earth metal aluminofluorosilicate glass comprises (a) 50 to 95% by weight of coarse particles having a spherical shape and an F/Si ratio of at least 0.1 but lower than 0.6 and having a particle size larger than 3 .mu.m but not larger than 50 .mu.m and (b) 5 to 50% by weight of fine particles having an F/Si ratio of 0.6 to 5 and a particle size of up to 3 .mu.m.This cement composition gives a cured body having a good surface gloss and a high strength, and this cement composition has a good flowability and a good workability. Accordingly, the cement composition is valuable as a dental cement composition.

Abstract: A process for producing high quality optical glass from fluoride glasses comprising preparing a melt of the glass and then cooling the melt in-situ inside the melt crucible. The in-situ quenching technique can be improved by narrowing the temperature range between the liquidus temperature and the glass transition temperature of the glass. The stability of the fluoride glass can be increased and the liquidus temperature of the glass can be lowered by doping the glass with a chloride dopant. Thorium tetrafluoride can be added to the chloride-doped glass in order to increase the chemical stability of the glass.

Abstract: A new, simplified method of fabricating optically transparent fluoride glasses containing ZrF.sub.4 and/or HfF.sub.4 has been developed which relies on a high vacuum pre-treatment for surface dehydration, melting in a rigorously inert argon atmosphere, and incorporation of a nonvolatile metallic oxidant in the melt such as InF.sub.3 and SnF.sub.4. Previous method for making these glasses have relied on either addition of ammonium bifluoride into the batch materials, or melting in an oxidizing atmosphere (so-called reactive atmosphere processing or RAP); both of these latter techniques have significant drawbacks.

Abstract: Halide fibres are protected by coatings up to 2 .mu.m thick of chalcogenide glasses, eg glasses based on compounds of S, Se or Te with Ge or As. The coatings are deposited on the fibre preform by ion deposition sputtering. Preferably the preform is ethced by directing a stream of inert ions at it. Most suitably the etching immediately precedes the coating.

Abstract: Glass compositions for high efficiency erbium.sup.3+ -doped optical fiber lasers, amplifiers and superluminescent sources are optimized for pumping by high power solid state lasers in the vicinity of 800 nm to provide amplified signals in wavelengths between 1.5 and 1.7 microns, a principal telecommunications window. A number of suitable host glasses for doping with erbium 3+ are identified wherein the excited state absorption/ground state absorption intensity ratio calculated at 800 nm is 1.00 or less.

Abstract: A new, simplified method of fabricating optically transparent fluoride glasses containing ZrF.sub.4 and/or HfF.sub.4 has been developed which relies on a high vacuum pretreatment for surface dehydration, melting in a rigorously inert argon atmosphere, and incorporation of a nonvolatile metallic oxidant in the melt such as InF.sub.3 or SnF.sub.4. Previous methods for making these glasses have relied on either addition of ammonium bifluoride into the batch materials, or melting in an oxidizing atmosphere (so-called reactive atmosphere processing or RAP); both of these latter techniques have significant drawbacks.

Abstract: A chalcogenide glass capable of infrared transmission which is either sulfur, selenium or tellurium based and consists of compositions of the formula MX+M.sub.2 'X.sub.3 +SiX.sub.2, wherein M is one of the metals calcium, strontium, barium, zinc and lead, and M' is either aluminum or gallium and X is either sulfur, selenium or tellurium. Aluminum or gallium chalcogenide acts to increase the covalent bonding network structure of the glass with the result being that excellent high temperature 8-14 micron IR transmitting glasses with transition temperatures above 500.degree. C. are prepared.

Abstract: An improved method of rapidly forming halide glass wherein the heating and cooling schedule has two phases of heating and cooling. This improved method substantially limits the loss of volatile components because of the significantly shortened interval of time at the elevated melting temperatures. The average time under heating is about 80 minutes. Cooling is as rapid as possible. The homogenization occurs above 800.degree. C. for about 20 minutes.

Abstract: In amorphous silicon nitride powder, from 0.5 to 40 mol % of the silicon are replaced by one or more of the elements boron, aluminum, yttrium, lanthanum, titanium, zirconium, tungsten and molybdenum.The powder is obtained by reacting the halides of the corresponding elements, which are dissolved in an inert organic solvent in the particular ratio desired, with ammonia. The solid reaction product formed is separated off from the liquid phase and treated at from 800.degree. to 100.degree. C.The powder is particularly suitable as a starting material for the production of sintered articles.

Abstract: A process for the preparation of metal fluorides usable for the production of fluoride glasses consists of reacting in an organic liquid medium, such as toluene, (a) a compound of said metal chosen from among the gaseous compounds thereof, the compounds of said metal soluble in the organic liquid medium and the compounds of said metal in solution in an organic solvent miscible with said medium, and (b) a fluorinating agent chosen from among the gaseous fluorinating agents, the fluorinating agents which are partly soluble in the organic medium and the fluorinating agents which are partly soluble in an organic solvent miscible with said medium, to form a fluoride of said metal, the organic liquid medium being such that it reacts neither with the compound of the metal, nor with the fluorinating agent and does not dissolve the fluoride formed. To prepare the zirconium tetrafluoride, it is possible to introduce in toluene, gaseous Zr(BH.sub.4).sub.

Abstract: A process for treating a halide, e.g. fluoride, glass composition, characterized by contacting a melt of the composition (3) with dry oxygen (6). Oxygen, simply on contact with a fluoride glass melt, converts transition metals, e.g. from Fe(II) to Fe(III), from one stable state to another and thereby reduces loss at transmission wavelengths in optical fibre, e.g. the loss at 2.6 .mu.m attributabel to Fe(II).

Abstract: The fluoride glass of the present invention, which contains, as anions, a small amount of chlorine in addition to fluorine, has advantages such as (1) it is less liable to crystallize as compared with a fluoride glass containing no chlorine and yet shows substantially no deterioration in chemical durability and mechanical strength due to chlorine inclusion and (2) its refractive index can easily be changed by changing the addition amount of chlorine.

Abstract: An improved method of making carbon dioxide and chlorine free fluoride-based glass wherein the atmosphere in the furnace enclosure is sulphur hexafluoride gas at a positive over pressure.

Abstract: The method consists of diffusing a doping compound in the region of a fluorozirconate glass support, wherein the optical guide is to be fabricated. The remaining regions are suitably masked to avoid any possible ionic exchange.

Abstract: The present invention concerns a glass-like carbon material which may be bonded to other materials, the carbon material having a high thermal expansion coefficient and being highly applicable for use as a slider part for a recording medium.

Abstract: An optically transmittant body comprising a solid solution of a ternary sulfide and a selected binary sulfide such as a solid solution of calcium lanthanum sulfide and phase lanthanum sulfide is provided by precipitating out of a nitrate solution of calcium and lanthanum, a starting powder of calcium carbonate and lanthanum carbonate. The molar ratio of lanthanum to calcium is greater than 2.0 moles lanthanum to 1.0 moles of calcium nitrate. The starting powder is reacted with a sulfurizing agent such as hydrogen sulfide to convert such starting powder into a powder of the solid solution of calcium lanthanum sulfide and phase lanthanum sulfide. The precipitate ion reaction forms a homogenous fine particle size starting powder of calcium carbonate and lanthanum carbonate which is substantially and uniformly converted into the solid solution powder. The phase lanthanum sulfide has a similar crystallographic structure as the calcium lanthanum sulfide.

Abstract: A fluoride glass comprising AlF.sub.3, ZrF.sub.4 and/or HfF.sub.4, and at least one compound selected from CaF.sub.2, SrF.sub.2 and BaF.sub.2, and a fluoride glass comprising these components and at least one additional component selected from MgF.sub.2, YF.sub.3, NaF and other like compounds have the advantages that there hardly occurs crystallization in the production thereof, and that they are excellent in chemical durability, high in surface hardness, so that they can ideally serve as glass to be used for low loss optical fiber, infrared optical fiber for thermometer, infrared laser window, etc.

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: Fluoride glasses comprise at least one fluoride of each of the following five categories:______________________________________ Fluorides Molar amount % ______________________________________ M.sup.1 F.sub.3 u M.sup.2 F.sub.4 v M.sup.3 F.sub.2 w M.sup.4 F.sub.3 x M.sup.5 F.sub.2 y ______________________________________wherein M.sup.1 represents In or Ga; M.sup.2 represents Th or U; M.sup.3 represents Ba or Pb; M.sup.4 represents Y, Yb or Lu; M.sup.5 represents Zn or Mn; and wherein u=25-35; v=5-12; w=25-35; x=5-12; and y=15-30; and optionally, at least one adjuvant or dopant present in a molar percent, z, wherein z=0-4. This composition is capable of providing, by casting in the molten state, followed by cooling, pieces of glass having a thickness greater than 10 mm. The specification also describes a method of producing these fluoride glasses.

Abstract: A solid vitreous composition has the formula: Te.sub.100-x-z X.sub.x Z.sub.z wherein x represents chlorine, bromine or iodine, Z represents sulfur and/or selenium; x represents the molar percentage of X and ranges from 5 to 67; z represents the molar percentage of Z and ranged from 0 to 60; it being understood that the sum (x+z) ranges from 33 to 85. A method for the preparation of this composition is disclosed as is its use in the field of optoelectronics and infra-red transmission.

Abstract: A process for treating a halide, e.g. fluoride, glass composition, characterized by contacting a melt of the composition with dry oxygen. Oxygen, simply on contact with a fluoride glass melt, converts transition metals, e.g. from Fe(II) to Fe(III), from one stable state to another and thereby reduces loss at transmission wavelengths in optical fiber, e.g. the loss at 2.7 .mu.m attributable to Fe(II).

Abstract: A Faraday rotation single-mode fiber having a high Verdet constant is disclosed, the core and the cladding of the fiber being made of a glass having the following composition: 26 to 38 mol % SiO.sub.2, 18 to 34 mol % B.sub.2 O.sub.3, 17 to 26 mol % Al.sub.2 O.sub.3, 18 to 32 mol % Tb.sub.2 O.sub.3, 0 to 5 mol % ZrO.sub.2, 0 to 5 mol % Ce.sub.2 O.sub.3, 0 to 5 mol % Pr.sub.2 O.sub.3, 0 to 5 mol % Dy.sub.2 O.sub.3 and 0 to 5 mol % Ho.sub.2 O.sub.3, provided that the total amount of the above ingredients is not less than 97 mol % and the total amount of Ce.sub.2 O.sub.3, Pr.sub.2 O.sub.3, Dy.sub.2 O.sub.3 and Ho.sub.2 O.sub.3 is 0 to 5 mol %.

Abstract: Fluoroglasses, their preparation and intermediate products obtained. These glasses are characterized by containing as the forming element at least about 10% by moles of a metal fluoride or mixture of metal fluorides of the formula MF.sub.n, n being a number equal to 3 or 4, M representing a 5f transition metal when n=4 (fluoride MF.sub.4) and a 4f transition metal or yttrium when n=3 (fluoride MF.sub.3), it being understood that said glasses are free of hydrofluoric acid as the forming element.

Abstract: The process for manufacturing halide glasses uses a reaction between organometallic and inter-halide or halide-derived compounds, started at a temperature ranging from the highest melting temperature and the lowest boiling temperature of the compounds used.

Abstract: A chalcogenide glass having the following composition in atomic %:T1: 0.5-47Ge: 5-41Se: 2-58Te: 5-75T1+Ge+Se+Te: at least 80%.

Abstract: Infrared-transparent bi- or multicomponent chalcogenide glasses based on germanium and selenium are improved by doping with 0.05 to 1.0 atom % of at least one of the alkaline earth metals calcium or strontium and/or one of their compounds. Optical fibers and optical elements can be made from these glasses.

Abstract: Disclosed is BeF.sub.2 -based optical fiber. Such fiber can have, in addition to low loss, other advantageous properties. For instance, BeF.sub.2 -based dispersion shifted single mode fiber can have lower core-cladding index difference and larger core diameter than the corresponding SiO.sub.2 -based fiber, and BeF.sub.2 -based graded index multimode fiber can have larger bandwidth than the corresponding SiO.sub.2 -based fiber. The inventive fibers have a core and a cladding containing at least 30 mol % BeF.sub.2, and may contain up to 40 mol % of AlF.sub.3, and one or more members of the group consisting of NaF, KF, MgF.sub.2, CaF.sub.2, PbF.sub.2, PF.sub.5, and SiF.sub.4. An exemplary and currently preferred glass has nominal composition (in mol percent) 30KF-(15-x)CaF.sub.2 -xPbF.sub.2 -10AlF.sub.3 -45BeF.sub.2, with x.ltoreq.15. Single mode fibers according to the invention have minimum total dispersion in the range 1.5-2.0 .mu.m, and typically have 0.25%.ltoreq..DELTA..sub.esi .ltoreq.0.6%, and 2.5 .mu.m.

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.

Abstract: The invention relates to a beryllium free fluoride glass composition used to prepare fluoride glass and the fluoride glass prepared by the composition. The fluoride composition contains only fluoride compounds and does not contain any oxygen atoms.

Abstract: The invention gives a coating with a very high vitrification rate. The resulting surface has physicochemical characteristics which are similar to those of fluoride glass. In order to achieve this result, the material constituting the fluoride glass enamel quickly crosses the temperature range between the melting point and the glossy transition temperature. Moreover, the metallic substrate temperature must be high enough to enable an active physiochemical process at the glass-metal interface which results in a correct "hooking". A "hooking" temperature is higher than one where a physical adhesion occurs, which results from Van der Waals interactions without any formation of chemical bonds at the glass-metal interface. The particular chemical reactivity of molten fluorides, which otherwise results in critical problems of corrosion, is in this case a favorable factor which generally reduces the hooking temperature to a level which is far below the glass melting temperature.

Abstract: Process for treating molten mixtures of fluorozirconate glass to form high purity infrared transparent glass which is essentially free of zirconium fluoride disassociation impurities and anion impurities. The molten mixture or melt is treated with a moisture-free oxygen reactive atmosphere to prevent formation of disassociation impurities or to remove any of these impurities already present in the melt. The melt is also contacted simultaneously or subsequently with a fluorine species reactive gas to remove any oxygen anion impurities formed during the oxygen reactive atmosphere treatment of the melt to thereby provide a glass having complete fluorine stoichiometry and which is free of disassociation and anion impurities.

Abstract: An electroluminescent device has an active electroluminescent layer 3 backed by a resistive layer 4 formed of an amorphous chalcogenide glass. The amorphous chalcogenide glass may comprise germanium, arsenic and/or antimony and selenium. The device comprises a glass base 1 on which there is supported a patterned transparent electrically conducting layer 2, the active luminescent layer 3, the amorphous chalcogenide glass backing layer 4, an optional dielectric layer 5 and an electrode 6. When an operating voltage is applied between layer 2 and electrode 6 the pattern in layer 2 becomes visible through base layer 1 and the contrast of the pattern is enhanced by the dark background produced by the backing layer 4.

Abstract: Halogenated glass comprising 20 to 90 mole percent of at least one of cadmium, manganese and zinc halide and a process for the preparation thereof.

Abstract: A selenium-base chalcogenide glass for use as optical fibers suitable for transmitting with low loss infrared rays, particularly that of 10.6 .mu.m in wavelength, is provided. The infrared optical fibers with low transmission loss, which is suitable for practical use, are obtained by incorporating 2 to 100 ppm of at least one of Al Ga, and In into a selenium-base chalcogenide glass, thereby to reduce the absorption due to the vibration of Ge--O bond formed by the contamination with oxygen. The infrared optical fibers made of such a glass material show a transmission loss of 3-4 dB/m which is less than 1/2.5 of the loss (10 dB/m) of a reference glass.

Abstract: A fluoride glass for infrared optical transmission fiber is purified for dehydration and deoxidation to reduce transmission loss by reacting melted fluoride glass with NF.sub.3 gas at temperature between 500.degree. C. and 800.degree. C. No scattering loss is increased by the present purification as decomposed product in the reaction does not precipitate.