Abstract:
A method for manufacturing an optical fiber, the method including the steps of providing a substrate tube; depositing a boron-free cladding layer; depositing a core comprising a glass including silica, and oxides of Al, Ge, Er, and Tm; collapsing the substrate tube to form a preform; and drawing the preform to yield optical fiber. A co-doped silicate optical waveguide having a core including silica, aluminum, germanium, erbium and thulium. The composition concentrations are: Er from 15 ppm to 3000 ppm; Al from 0.5 mol% to 12 mol%; Tm from 15 ppm to 10000 ppm; and Ge from 1 mol% to 20 mol%. In a specific embodiment, the concentration of Er is from 150 ppm to 1500 ppm; Al is from 2 mol% to 8 mol%; and Tm is from 15 ppm to 3000 ppm.
Abstract:
The invention relates to a waveguide laser or amplifier material comprising a silica glass host material, one or more rare earth elements in total concentration CRE at.%, one or more network modifier elements selected from the group of tri- or penta-valent atoms of the periodic table of the elements in total concentration CNME at.%, wherein the ratio of atomic concentrations of the modifier elements to that of the rare earth elements CNWCRE is larger than or equal to 1, and wherein the total atomic concentration of rare earth and the tri-valent network modifiers, such as aluminium and/or boron, is substantially equal to the atomic concentration of the penta-valent network modifier, such as phosphorous. Such materials exhibit reduced risk of photo darkening.
Abstract:
A method for manufacturing an optical fiber and the resulting article. The method including the steps of: providing a substrate tube; depositing high purity silica-based cladding layers on the inside of the tube; depositing a germanium-free core comprising a glass including silica, and oxides of Al, La, Er, and Tm; collapsing the substrate tube to form a preform; and drawing the preform to yield an optical fiber. A germanium-free co-doped silicate optical waveguide in accordance with the present invention includes a core material comprising silica, aluminum, lanthanum, erbium and thulium, wherein the concentration of Er is from 15 ppm to 3000 ppm; Al is from 0.5 mol% to 15 mol%; La is less than 2 mol%; and Tm is from 150 ppm to 10000 ppm. In an exemplary specific embodiment the concentration of Al is from 4 mol% to 10 mol%; and the concentration of Tm is from 150 ppm to 3000 ppm. The core may further include F. In an exemplary embodiment, the concentration of F is less than or equal to 6 mol%. The waveguide may be an optical fiber, a shaped fiber or other light-guiding waveguides. An amplifier according to the present invention includes the optical fiber described above.
Abstract:
Process for producing a sintered granular material containing silicon dioxide and having a BET surface area of less than 1 m 2 g and a proportion of impurities of less than 50 ppm, in which a mixture which contains silicon dioxide powder and a metal compound is intensively mixed in an atmosphere having a relative atmospheric humidity of from 1.0 to 100% at temperatures of from 0 to 50°C by means of a dispersing apparatus, the crumbly mass is divided into pieces, subsequently dried, purified 'and sintered. The moisture content of the silicon dioxide powder and/or the atmospheric humidity are/is at least sufficient to hydrolyse the metal compound completely.
Abstract:
A method for manufacturing an optical fiber, the method including the steps of providing a substrate tube; depositing a boron-free cladding layer; depositing a core comprising a glass including silica, and oxides of Al, Ge, Er, and Tm; collapsing the substrate tube to form a preform; and drawing the preform to yield optical fiber. A co-doped silicate optical waveguide having a core including silica, aluminum, germanium, erbium and thulium. The composition concentrations are: Er from 15 ppm to 3000 ppm; Al from 0.5 mol% to 12 mol%; Tm from 15 ppm to 10000 ppm; and Ge from 1 mol% to 20 mol%. In a specific embodiment, the concentration of Er is from 150 ppm to 1500 ppm; Al is from 2 mol% to 8 mol%; and Tm is from 15 ppm to 3000 ppm.
Abstract:
An optical waveguide including a core having silica, Al, a non-fluorescent rare-earth ion, Ge, Er, and Tm. The non-fluorescent rare-earth ion may be La. Exemplary compositions concentrations are Er is from 15 ppm to 3000 ppm, Al is from 0.5 mol% to 12 mol%, La is less than or equal to 2 mol%, Tm is from 15 ppm to 10,000 ppm; and the Ge is less than or equal to 15 mol%. The core may further include F. An exemplary concentration of F is less than or equal to 6 anion mol%.