Abstract: There is provided alkaloid halogen-doped sulfide glasses for an optical amplifier and a fabricating method thereof. An alkaloid halogen-doped sulfide glass is formed of silica doped with a Ge—Ga—S three-component system, Pr3+, and an alkaloid halogen. To fabricate the alkaloid halogen-doped sulfide glass for an optical amplifier, silica doped with Ge, Ga, S, Pr3+, and an alkaloid halogen as a starting material is filled into a container. The container is sealed in a vacuum and the starting material in the container is fused by heating the container. The container is cooled and the starting material is sintered by heating the container at a glass transition temperature.

Abstract: The invention provides a UV below 200 nm lithography method. The invention includes providing a below 200 nm radiation source for producing <200-nm light, providing a plurality of mixed cubic fluoride crystal optical elements, with the fluoride crystals comprised of a combination of alkaline earth cations having different optical polarizabilities such as to produce an overall isotropic polarizability which minimizes the fluoride crystal spatial dispersion below 200 nm, transmitting <200-nm light through the cubic fluoride crystal optical elements, forming a lithography pattern with the light, reducing the lithography pattern and projecting the lithography pattern with the cubic fluoride crystal optical elements onto a UV radiation sensitive lithography printing medium to form a printed lithographic pattern. The invention includes making the mixed fluoride crystals and forming optical element therefrom.

Abstract: A glass includes (a) a matrix containing a compound of at least one nonmetallic element; and (b) a particle selectively formed in the matrix. This particle is made of the at least one nonmetallic element. A process for producing such glass includes (a) providing a blank glass containing a compound of at least one nonmetallic element; (b) condensing a pulsed laser beam to a focal point in the blank glass such that a particle is selectively formed in the blank glass at a position corresponding to the focal point, the particle being made of the at least one nonmetallic element dissociated from the compound; and (c) moving the focal point in the blank glass to produce a pattern of the particle. The glass is suitable for optical functional elements.

Abstract: A method of making chalcogenide glass which utilizes liquid encapsulation to prevent the evaporation loss of low boiling point or high vapor pressure glass components while the glass melt is being processed.

Abstract: No-bridging fluorine sites in calcium fluoride (CaF2) caused by lanthanide, transition metal or actinide impurities are eliminated by doping the CaF2 with sodium or another monovalent anionic dopant during or after growth of the crystal. This doping technique may be applied in the growth of other UV-transmissive fluoride materials in a family designated by a general formula Z:XFN where X is one or some combination of magnesium, calcium, zinc, strontium, cadmium, and barium, Z is one or some combination of lithium, sodium, potassium, rubidium, cesium, thallium, copper, silver and gold, and N is an integer in the range 1 through 6, and dependant on X. Elimination of the non-bridging fluorine sites can provide solarization resistant materials with low UV absorption even when the material contains sufficient lanthanide transition metal, or actinide impurities to cause the fluoride materials to be highly absorbing for UV radiation in the absence of the monovalent anion doping.

Abstract: The invention resides in a molecular, inorganic glass and a method of making the glass, the glass being vitreous and resistant to devitrification, that is composed, in substantial part at least, of thermally-stable, zero-dimensional clusters or molecules, composed of four atoms of arsenic and three atoms of sulfur, the glass further containing up to 12 atomic percent of germanium, adjoining clusters being bonded to each other primarily by van der Waals forces, and at least 95% of the glass composition consisting of 42-60% arsenic, 37-48% sulfur plus selenium, the selenium being 0-14%.

Abstract: A synthetic quartz glass for optical use, to be used by irradiation with light within a range of from the ultraviolet region to the vacuum ultraviolet region, which contains fluorine, which has a ratio of the scattering peak intensity of 2250 cm−1 (I2250) to the scattering peak intensity of 800 cm−1 (I800), i.e. I2250/I800, of at most 1×10−4 in the laser Raman spectrum, and which has an absorption coefficient of light of 245 nm of at most 2×10−3 cm−1.

Abstract: Two and three dimensional color image displays. The displays include a display medium having a substantially uniform dispersion of red, green and blue visible light emitting particles sized between approximately 0.5 to approximately 50 microns therethrough. The particles can be dye doped polymethylmethacrylate(pmma) plastic, and the display medium can be pmma, acrylic plastic or glass. Other particles can be used such as rare earth doped crystals. The two dimensional display uses three laser sources each having different wavelengths that direct light beams to each of three different types of particle in the display medium. Light is absorbed by the particles which then become excited and emit visible fluorescence. Modulators, scanners and lens can be used to move and focus the laser beams to different pixels in order to form the two dimensional images having different visible colors.

Abstract: The invention provides a high quality identifiable fluoride crystalline optical microlithography lens element blank for formation into an lens element of a microlithography system. The highly qualified fluoride crystalline characteristics of the fluoride optical lithography lens blank ensure its beneficial performance in the demanding microlithography manufacturing regime which utilizes high energy short wavelength ultraviolet laser sources. The fluoride crystalline optical lithography lens element blanks are comprised of multiple adjoining abutting crystalline subgrains with low boundary angles.

Abstract: A glass ceramic material for storing energy of X-rays and releasing said energy by photo-stimulation comprising a fluoride glass matrix containing micro-crystalline particles, said particles having an average particle size, d, so that d<2 &mgr;m and said glass ceramic shows in a XRD spectrum a continuous spectrum of said glass matrix and discrete peaks superimposed on said continuous spectrum. Said glass matrix contains preferably zirconium ions and ions selected from the group consisting of alkali ions and alkaline earth ions, at least 5 mole % of the fluoride ions is replaced by bromide and/or chloride ions and at least 0.01 mole % of cations selected from the group consisting of transition metal ions, rare earth metal ions, In+, Ga+, Tl+, and Pb2+ is present.

Abstract: There is provided alkaloid halogen-doped sulfide glasses for an optical amplifier and a fabricating method thereof. An alkaloid halogen-doped sulfide glass is formed of silica doped with a Ge-Ga-S three-component system, Pr3+, and an alkaloid halogen. To fabricate the alkaloid halogen-doped sulfide glass for an optical amplifier, silica doped with Ge, Ga, S, Pr3+, and an alkaloid halogen as a starting material is filled into a container. The container is sealed in a vacuum and the starting material in the container is fused by heating the container. The container is cooled and the starting material is sintered by heating the container at a glass transition temperature.

Abstract: Two and three dimensional color image displays. The displays include a display medium having a substantially uniform dispersion of red, green and blue visible light emitting particles sized between approximately 0.5 to approximately 50 microns therethrough. The particles can be dye doped polymethylmethacrylate(pmma) plastic, and the display medium can be pmma, acrylic plastic or glass. Other particles can be used such as rare earth doped crystals. The two dimensional display uses three laser sources each having different wavelengths that direct light beams to each of three different types of particle in the display medium. Light is absorbed by the particles which then become excited and emit visible fluorescence. Modulators, scanners and lens can be used to move and focus the laser beams to different pixels in order to form the two dimensional images having different visible colors.

Abstract: A GeAs sulphide glass family of transparent glasses having transmission far into the infrared portion of the spectrum, containing a source of phosphorus ion as a co-dopant to effect dispersion of a rare earth metal ion dopant in the glass, an optical component comprising the glass, and a method of dispersing a rare earth metal ion in the glass.

Abstract: The invention reflects discovery of a liquid phase doping technique that, unlike previous techniques, exhibits very little fluorine depletion upon subsequent heating. The invention involves the steps of providing a silica sol comprising a tetraalkylammonium hydroxide and a di-, tri-, or tetraalkylammonium fluoride, the sol having pH of about 10 to about 14, adding a gelling agent to the sol to induce gelation, casting or extruding the sol to form a gel body, and then drying, heat treating, and sintering the body. Advantageously, the fluorine-containing compound is tetramethylammonium fluoride.

Abstract: The present invention is directed to a fluorinated rare earth doped glass composition and method for making a glass-ceramic optical article therefrom, e.g. optical fiber waveguides, fiber lasers and active fiber amplifiers, having application in the 1300 nm and 1550 nm telecommunications windows. The inventive compositions include Pr3+ and/or Dy3+ in a concentration range of between 300-2,000 ppmw and Ag+ in a concentration range of between 500-2,000 ppmw; or Er3+ in a concentration range of between 500-5,000 ppmw and Ag+ in a concentration range of between 0-2,000 ppmw. The monovalent silver ion provides an ionic charge balanced glass-ceramic crystal. These compositions exhibit reduced or absent rare earth ion clustering and fluorescence quenching effects in the presence of high concentrations of rare earth ion dopants.

Abstract: A heavy metal fluoride glass composition range (in mol percent) consisting essentially of: (16-30)BaF2.(8-26)HfF4.(6-24)InF3 or GaF3.(4-16)CdF2.(6-24)YbF3.(4-22)ZnF2. In an alternative embodiment, a heavy metal fluoride glass composition range (in mol percent) comprises (16-30)BaF2.(8-26)HfF4.(6-24) of (0-24)InF3, (0-24)GaF3 and (0-19)AlF3.(1-16)CdF2.(6-24)YbF3.(4-26)ZnF2. A preferred heavy metal fluoride glass produced in accordance with the present invention comprises a composition (in mol %) and comprises about 26BaF2.18HfF4.7InF3.5GaF3.10CdF2.18YbF3.16ZnF2. A preferred heavy metal fluoride glass has maximum thickness of most preferably about 3 mm. Another preferred heavy metal fluoride glass comprises a composition (in mol %) and comprises about 26BaF2.18HfF4.12AlF3.10CdF2.18YbF3.16ZnF2.

Abstract: Disclosed herein is a low phonon energy glass and a fiber made therefrom. e glass includes the following components given in mol percent:______________________________________ germanium 0.1-30 arsenic 0-40 X 0.01-20 Y 40-85 ______________________________________wherein X is selected from the group consisting of gallium, indium and mixtures thereof wherein Y is selected from the group consisting of selenium, and mixtures of selenium and up to 50% of sulfur substituted for selenium and the glass also contains 0.001-2 weight percent of a rare earth, based on the weight of said components. The fiber has a minimum loss of less than 5 dB/m.

Abstract: Chalcogenide glass fibers having a glass core with two cladding glass layers, the second cladding glass layer having a refractive index lower than that of the core glass and higher than that of the first cladding glass. The core glass does not contain germanium. Glass fiber having this core-cladding structure is mechanically strong and exhibits only small transmission loss of infrared light passing through the fiber.

Abstract: An optical fiber amplifier is formed from glass doped with praseodymium. The glass may include one or more of cadmium mixed halide, hafnium halides, geranium and silicon disulphide based vitreous materials or fluorozirconate glass fibers.

Abstract: A telluride glass with glass transition temperature above 150.degree. C., fference between the crystallization temperature and the glass transition temperature of above 200.degree. C., and extended transmission in the infrared region of radiation of up to 20 microns having, on mol basis, 20-60% tellurium, 10-50% arsenic, 4-35% germanium, 0.5-15% gallium, up to 15% iodine, and up to 30% selenium. All or part of the gallium can be replaced with indium and the glass can contain up to 5%, based on the weight of the glass components, of a rare earth ion to render the glass fluorescent. Optical fibers drawn from these glasses have shown mid infrared fluorescence and may have as a bright source of IR light.

Abstract: A process for manufacturing a semiconductor, including generating a first plasma of a V group element from a V group element source; generating a second plasma of an auxiliary material for activating a metal organic compound containing a III group element separately from and at the same time as the first plasma; adding the vaporized metal organic compound and the plasma of the auxiliary material to the plasma of the V group element; and forming, on a substrate, a film of a semiconductor compound containing the III group element and the V group element. A semiconductor and a semiconductor device having high quality and high functions can be manufactured in a short time at high yield. An amorphous material includes at least hydrogen, a III Group element, preferably gallium, and nitrogen. In the infrared absorption spectrum measured of the amorphous material, the ratio of the absorbance I.sub.N-H, at the absorption peak indicating the bond (N--H) between nitrogen and hydrogen to that, I.sub.

Abstract: The specification describes a method for the manufacture of fluoride glass optical fibers which are covered with a protective coating of phosphate glass. The coating is produced by dipping the fluoride glass preform in a phosphate glass melt prior to drawing the optical fiber. The fluoride glass is ZBLAN. The phosphate glass has a glass transition temperature below 200.degree. C., which allows the dipping step to be carried out at a relatively low temperature where the preform temperature is maintained well below the crystallization temperature of the fluoride glass, and also where the viscosity of the fluoride glass preform is substantially higher than the viscosity of the phosphate glass coating material.

Abstract: A glass-ceramic material that is doped with rare-earths and is especially suitable for lasers and optical amplifiers is disclosed. The glass-ceramic material is optically non-scattering, and the doping with rare earths is essentially in the microcrystalline phase. The glass-ceramic material is preferably made up from complexes of metals having a valency of three or greater and of halides of rare earth ions having a valency of three or greater. The rare-earth ions include an optically active rare-earth ion.

Abstract: Disclosed are an optical fiber comprising a core and a cladding wherein the core is composed of a In-Ga-Cd-Pb halide glass and the clad composed of a halide glass possesses a refractive index of 1.515 or less, which has a large specific refractive index difference (.DELTA.n) and a large numerical aperture, and such an optical fiber as mentioned above wherein the core contains one or more activating ions as well as an optical fiber amplifier comprising a pumping source, a laser glass fiber and a means for introducing pumping light and signal light into the above laser glass fiber, wherein the laser glass fiber is the optical fiber of the present invention mentioned above.

Abstract: A selenide glass with improved mechanical and optical properties such as ended transmission in the infrared region of radiation having wavelengths beyond 15 microns; Tg in the region of 363.degree.-394.degree. C.; and thermal stability of 85.degree.-145.degree. C. based on the difference between T.sub.g and T.sub.x, comprising, on mol basis, 20-70% germanium selenide, 0.5-25% gallium selenide, indium selenide or mixtures thereof; and 5-50% of at least one alkaline earth in selenide form is described. A process for improving mechanical and optical properties of a selenide glass based on germanium selenide comprises the steps of mixing glass components, including a modifier in elemental or selenide form; melting the glass components to form a molten mixture; cooling the molten glass mixture to a solid state; annealing the solid glass; and cooling the annealed glass to about room temperature is also described.

Abstract: Hydrogen and/or carbon impurities are removed from chalcogenide or chalcoide glasses by the addition of a halide, such as TeCl.sub.4, to the batch composition. During melting of the batch composition, the metal halide reacts with the hydrogen and/or carbon impurities to form a hydrogen halide and/or carbon tetrahalide gas and a metal which becomes incorporated into the chalcogen-based glass. Useful halides include halides of sulfur, selenium, tellurium, polonium, or halides of a metal (such as aluminum, magnesium, zirconium, or a mixture thereof) that forms a stable oxide. Mixed metal halides may also be used. The glass melt is then distilled, outgassed, homogenized, fined, and annealed. An apparatus specially designed for making a fiber preform by the above process is also described. An annealed preform made by this method may be drawn into a low-loss fiber in the 2 .mu.m to 12 .mu.m range.

Abstract: A halide glass composition contains iodide and/or bromide. In addition the halide content preferably includes chloride. The preferred metal composition includes no aluminium and 1-10 mole % of (In+Y). These compositions are used as hosts for rare earth lasing dopants, e.g, Pr.sup.3+.

Abstract: Disclosed are laser glasses composed of a Ga--Na--S glasses doped with one or more kinds of activating ions, laser glass fibers comprising a core and a clad wherein the core is composed of the above-mentioned laser glasses of the present invention and optical fiber amplifiers comprising a pumping source, a laser glass fiber and a means for introducing pumping light and signal light into the laser glass fiber wherein the laser glass fiber is the above-mentioned laser glass fiber of the present invention. The laser glasses of the present invention show high radiative quantum efficiency and host glass stability and can be produced easily.

Abstract: An acute matrix liquid crystal display panel including 1) a plurality of liquid crystal display elements distributed in a matrix of rows and columns; 2) means for supplying video signals and display element selection signals, including row and column conductors; and 3) a plurality of paired Ovonic threshold switches and resistive elements each serially coupled between the corresponding row or column conductor and the liquid crystal display element, the Ovonic threshold switches acting as display element selection devices and current isolation devices in which the Ovonic threshold switches having an off state resistance of at least 1.times.10.sup.9 ohms.

Abstract: Lead-containing fluoride glass comprises 50-70 mol % of ZrF.sub.4, 3-5 mol % of LaF.sub.3, 0.1-3 mol % of YF.sub.3, and 2-15 mol % of NaF and/or LiF and/or CsF, where LaF.sub.3 +YF.sub.3 =4.5-6 mol %, and further comprises lead. An optical fiber comprises a core made of the lead-containing fluoride glass and a cladding surrounding the core. A process for producing an optical fiber comprises forming a base material for a core of the lead-containing fluoride glass, forming a base material for a cladding of fluoride glass containing 30-60 mol % of HfF.sub.4, and drawing the base materials into an optical fiber at a drawing temperature of 315-340 .degree. C.

Abstract: Vitrified phosphor articles, intermediates, and methods for preparing the articles. In the methods, a combination of species are admixed. The combination of species are precursors for a glass-forming system. The glass-forming system includes precursors for a crystalline radiographic phosphor. The admixed combination of species are fired to form a melt having a single liquid. The product of the melt is molten-shaped.

Abstract: A heavy metal fluoride glass composition for an optical fiber in mole percent, about: 20 to 40% InF.sub.3, 20 to 0% GaF.sub.3, 2 to 10% PbF.sub.2, 0 to 25% ZnF.sub.2, 0 to 25% CdF.sub.2,10 to 25% BaF.sub.2, 0 to 6% NaCl, 0 to 6% NaF, 0 to 7% SrF.sub.2 and 0 to 5% CaF.sub.2 ; the total of InF.sub.3 and GaF.sub.3 being about 40%; the total of BaF.sub.2, SrF.sub.2 and CaF.sub.2 being about 25%; the total of ZnF.sub.2 and CdF.sub.2 being about 25%, and the total of NaCl and NaF being about 6%; said composition being further doped with a lanthanide series heavy metal fluoride in amount up to about 1%.

Abstract: A preferred embodiment of a sulfide glass with improved mechanical and optical properties such as extended transmission in the infrared region of radiation having wavelengths of up to about 15 microns, Tg in the range of 370.degree.-550.degree. C., and thermal stability of 100.degree.-300.degree. C., containing, on mol basis, 36-72% germanium sulfide, 2-38% gallium sulfide and/or indium sulfide, and 26-62% of at least one modifier containing an alkaline earth sulfide. A process for making glass of improved mechanical and optical properties comprises the steps of mixing glass components, including an alkaline earth modifier in elemental or sulfide form; melting the glass components in an inert vessel contained in a sealed ampoule to form a molten mixture; cooling the molten glass mixture to a solid state; annealing the solid glass; and cooling the annealed glass to about room temperature.

Abstract: A sulfide glass with improved mechanical and optical properties such as ended transmission in the infrared region of radiation having wavelengths of up to about 15 microns; Tg in the region of 410.degree.-550.degree. C.; and thermal stability of 100.degree.-300.degree. C. based on the difference between T.sub.g and T.sub.x, comprising, on mol basis, 20-90% germanium sulfide, 0-60% gallium sulfide, and 5-60% of at least one modifier in sulfide form. A process for improving mechanical and optical properties of a sulfide glass based on gallium sulfide and/or germanium sulfide comprises the steps of mixing glass components, including a modifier in elemental or sulfide form; melting the glass components to form a molten mixture; cooling the molten glass mixture to a solid state; annealing the solid glass; and cooling the annealed glass to about room temperature.

Abstract: The present invention concerns a process for obtaining metal halides, in particular rare earth and/or alkali earth halides. This process consists of forming a homogeneous solution by mixing one or more rare earth and/or alkali earth halogenoalkoxides in an anhydrous organic solvent, and hydrolyzing this solution. The novel materials are obtained at room temperature and are in powder, fibre, film or bulk material form.

Abstract: The present invention relates generally to a novel and unique class of gly materials and methods of making such materials in which substantially all of the anions are nitride ions, in contrast to the oxide ions of conventional optical glasses, or the fluoride ions of the more recently discovered fluoride optical glasses. The chemical nature of these new glasses dispose the glassy materials to a remarkable combination of desirable properties, including, but not limited to, high hardness, high refractive index and high softening temperature.

Abstract: Flourinated glasses containing indium fluoride and MF.sub.2 fluorides in at least 70 moles %, in which M denotes one or several elements of the group Ba, Sr, Ca, Pb. Said glasses contains, in the form of stabilizing elements, either 2 to 12 % gadolinium fluoride, or 2 to 10 % magnesium fluoride, or else a mixture of both fluorides in a proportion not exceeding 20 mole %. Variants of these compositions are also described.

Abstract: The present invention relates generally to a novel and unique class of gly materials and methods of making such materials in which substantially all of the anions are nitride ions, in contrast to the oxide ions of conventional optical glasses, or the fluoride ions of the more recently discovered fluoride optical glasses. The chemical nature of these new glasses dispose the glassy materials to a remarkable combination of desirable properties, including, but not limited to, high hardness, high refractive index and high softening temperature.

Abstract: Lead-containing fluoride glass comprises 50-70 mol % of ZrF.sub.4, 3-5 mol % of LaF.sub.3, 0.1-3 mol % of YF.sub.3, and 2-15 mol % of NaF and/or LiF and/or CsF, where LaF.sub.3 +YF.sub.3 =4.5-6 mol %, and further comprises lead. An optical fiber comprises a core made of the lead-containing fluoride glass and a cladding surrounding the core. A process for producing an optical fiber comprises forming a base material for a core of the lead-containing fluoride glass, forming a base material for a cladding of fluoride glass containing 30-60 mol % of HfF.sub.4, and drawing the base materials into an optical fiber at a drawing temperature of 315.degree.-340.degree. C.

Abstract: This invention is directed broadly to transparent glasses exhibiting excellent transmission far into the infrared region of the electromagnetic radiation spectrum, those glasses consisting essentially, expressed in terms of mole percent, of 40-80% Ga.sub.2 S.sub.3, 0-35% RS.sub.x, wherein R is at least one network forming cation selected from the group consisting of aluminum, antimony, arsenic, germanium, and indium, 1-50% Ln.sub.2 S.sub.3, wherein Ln is at least one cation selected from the group consisting of a rare earth metal cation and yttrium, 1-45% MS.sub.x, wherein M is at least one modifying metal cation selected from the group consisting of barium, cadmium, calcium, lead, lithium, mercury, potassium, silver, sodium, strontium, thallium, and tin, and 0-10% total chloride and/or fluoride. Glass compositions consisting essentially, expressed in terms of mole percent, of 5-30% Ga.sub.2 S.sub.3, 0-10% R.sub.2 S.sub.

Abstract: This invention is directed to the production of transparent glasses exhibiting excellent transmission far into the infrared region of the electromagnetic radiation spectrum, said glasses consisting essentially, expressed in terms of mole percent on the sulfide basis, of 55-95% GeS.sub.2, 2-40% As.sub.2 S.sub.3, 0.01-20% R.sub.2 S.sub.3, wherein R is at least one trivalent network forming cation selected from the group consisting of gallium and indium, 0-10% MS.sub.x, wherein M is at least one modifying cation selected from the group consisting of aluminum, barium, cadmium, calcium, lead, lithium, mercury, potassium, silver, sodium, strontium, thallium, tin, yttrium, and a rare earth metal of the lanthanide series, 0-20% total of at least one halide selected from the group consisting of chloride and fluoride, 0-5% total selenide, and wherein the sulfur and/or selenium content can vary between 85-125% of the stoichiometric value.

Abstract: Embodiments of the present invention are sulfur rich glass compositions comprising germanium, gallium and sulfur, which glass compositions have a low energy phonon spectrum and which glass compositions serve as a host for active materials in fabricating light sources such as fiber laser oscillators, light amplifiers, and superluminescent sources. In particular, such a laser oscillator, light amplifier or superluminescent source is comprised of an inventive glass composition which is doped with rare earth ions such as Pr.sup.3+ or Dy.sup.3+ for producing light output at wavelengths, among others, substantially at 1.3 um. Further embodiments of the present invention are light sources such as laser oscillators, light amplifiers and superluminescent sources which have emissions substantially at 1.3 um and which are comprised of an inventive glass composition which is doped with Dy.sup.3+ and Yb3+ ions, wherein Dy.sup.3+ ions are pumped by energy transfer from Yb3+ ions.

Abstract: A chalcogenide glass that is doped with praseodymium and contains a rare earth metal is disclosed. The rare earth metal is at least 10 mole percent of the metals in the glass. The concentration of the praseodymium in the glass is at least 200 ppm. The chalcogenide glass, when formed into an amplifier for an optical fiber transmission system, efficiently amplifies optical signals in the signal band of 1.3 .mu.m.

Abstract: A novel series of chalcogenide glass compositions that are relatively highly selective for a specific ion in solution. When utilized as a sensing element for electrodes or similar analytical devices, a modified surface layer is formed on the surface of the glass in contact with the test solution. The surface layer being characterized by a surface ionic conductivity ranging from 10.sup.-7 to 10.sup.-2 S/cm, a diffusion coefficient ranging from 10.sup.-11 to 10.sup.-6 cm.sup.2 /s and having a ratio of electronic to ionic conductivity within the modified surface layer of not more than 1.0. Specific compositions having these unique morphology and transport properties are disclosed for the detection of cadmium, silver, thallium, mercury, copper and lead.

Abstract: Optical fiber composed of a glass doped with at least laser-active ions of an element from the rare earths. An optical fiber of glass, preferably a HMF glass, doped with Tm.sup.3+ is operated at 1.48 .mu.m as a fiber laser or amplifier on the laser transition .sup.3 F.sub.4 -.sup.3 H.sub.4. Since this thereby involves a self-saturating transition, the terminal level is emptied in accelerated fashion for a continuous wave mode by co-doping with de-activators, preferably Ho.sup.3+, Tb.sup.3+, Eu.sup.3+ and/or Pr.sup.3+ ions. The pump light wavelength can be selected from the wavelength range from 700 through 890 nm of GaAlAs emission. The optical fiber can be used in optical amplifiers or fiber amplifiers.

Abstract: Vitreous solid compositions of formula I:Te.sub.w Se.sub.y X.sub.x Z.sub.z (I)whereinX represents at least one halogen selected from chlorine, bromine and iodine,Z represents at least one element selected from As, Sb and Bi,w, x, y and z represent the molar percentages respectively of elements Te, X, Se and Z,w being a number varying from 5 to 50,x being a number varying from 5 to x.sub.1,y being a number varying from 5 to 80,z being a number varying from 5 to z.sub.1,the numbers w, x, y and z being such that the sum (w+x+y+z) is equal to 100,the numbers x.sub.1 and z.sub.1 being such that:when X represents mostly iodine, x.sub.1 =50 and z.sub.1 =60,when X represents mostly bromine, x.sub.1 =60 and z.sub.1 =50, andwhen X represents mostly chlorine, x.sub.1 =60 and z.sub.

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, 30-40% NaF and/or NaCl, 2-20% total of BaF.sub.2 and/or BaCl.sub.2 +KF and/or KCl, consisting of 0-15% BaF.sub.2 and/or BaCl.sub.2 and 0-7% 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. The preferred glasses contain at least 2% each of BaF.sub.2 and/or BaCl.sub.2 and KF and/or KCl.

Abstract: The present invention relates to a process for the synthesis of fluoride glass by the sol-gel method.The object of the invention is to synthesize an impurity-free fluoride glass.This object is achieved with the aid of a process having stages consisting of preparing a wet oxygenated gel from precursors containing all the cations constituting said fluoride glass, hydrolyzing said gel, drying said gel and in which the process is characterized in that it also comprises the stage consisting of treating said oxygenated gel by a fluorinating agent in the vapour phase, at a temperature below the glass crystallization point.This process more particularly makes it possible to produce fluoride glass for optical fibres.

Abstract: Halide glass articles, e.g. rods, tubes and preforms for making fluoride glass fibres, are prepared by melting and/or casting the articles under a low pressure, e.g. 0.01 to 500 mbars and, during the low pressure regime, a gas flow rate of between 0.01 to 100 liters/min (measured at NTP) is maintained. It has been found that subjecting the melts to a low pressure reduces the attenuation of the fibre which eventually results from the melts.

Abstract: This invention is directed broadly to transparent glasses exhibiting excellent transmission far into the infrared region of the electromagnetic radiation spectrum, those glasses consisting essentially, expressed in terms of mole percent, of 40-80% Ga.sub.2 S.sub.3, 0-35% RS.sub.x, wherein R is at least one network forming cation selected from the group consisting of aluminum, antimony, arsenic, germanium, and indium, 1-50% Ln.sub.2 S.sub.3, wherein Ln is at least one cation selected from the group consisting of a rare earth metal cation and yttrium, 1-45% MS.sub.x, wherein M is at least one modifying metal cation selected from the group consisting of barium, cadmium, calcium, lead, lithium, mercury, potassium, silver, sodium, strontium, thallium, and tin, and 0-10% total chloride and/or fluoride. Glass compositions consisting essentially, expressed in terms of mole percent, of 5-30% Ga.sub.2 S.sub.3, 0-10% R.sub.2 S.sub.