Heraeus Quarzglas Gmbh & Co Kg

Heraeus Shin-etsu America, Inc.

Institut Fur Photonische Technologien

Shin-etsu Quartz Products Co., Ltd.

Leibniz-institut Fur Photonische Technologien E.v.

Institut Für Photonische Technologien E.v.

Thomas Kayser

Walter Lehmann

Michael Hünermann

Andreas Langner

Achim Hofmann

Matthias Otter

Martin Trommer

Stefan Ochs

Gerhard Schoetz

Mario Such

Heinz Fabian

Boris Gromann

Nigel Robert Whippey

Kay Schuster

Stephan Grimm

Katsuhiko Kemmochi

Bodo Kuehn

Gerrit Scheich

Sascha Pihan

Bodo Kühn

Hilmar Laudahn

Gerhard Schötz

Martin Arndt

Kathrin Wissel-Stoll

Mirko Wittrin

Robert Joseph Coolich

Volker Reichel

Markus Wilde

Johannes Kirchhof

Hardy Baierl

Jan Dellith

Michael HÜNERMANN

Marcus Constantin GÖBEL

Bastian Weisenseel

Matthias SÖHN

A process for the production of a fluorinated quartz glass including the steps of generating SiOparticles in a synthesis burner; depositing the resulting SiOparticles into a body; and vitrifying the resulting body, wherein a fluorinating agent having a boiling point greater than or equal to −10° C. is supplied to the synthesis burner.

Process for the preparation of fluorinated quartz glass

A process for producing a fluorinated quartz glass is described, including providing an SiOsoot body; reacting the SiOsoot body with a fluorinating agent having a boiling point of greater than or equal to −10° C. to obtain a fluorinated SiOsoot body; and vitrifying the fluorinated SiOsoot body.

Alternative fluorinating agents for the production of fluorinated quartz glass

One aspect relates to a process for the preparation of a quartz glass body. The process includes providing a silicon dioxide granulate I prepared from a pyrogenically produced silicon dioxide powder, treating the silicon dioxide granulate I with a reactant at a temperature in a range from 1000 to 1300&#xb0; C., and making a glass melt out of the silicon dioxide granulate. A quartz glass body is made out of at least a part of the glass melt. Furthermore, one aspect relates to a quartz glass body obtainable by this process. Furthermore, one aspect relates to a light guide, an illuminant, and a formed body, each of which is obtainable by further processing of the quartz glass body. One aspect additionally relates to a process for the preparation of a silicon dioxide granulate II.

Preparation of carbon-doped silicon dioxide granulate as an intermediate in the preparation of quartz glass

A method for producing a component with portions of a rare earth metal-doped quartz glass, an intermediate product containing voids and consisting of a SiOraw material doped with rare earth metal is introduced into a sinter mold the interior of which is bordered by a carbonaceous mold wall, and is melted therein into the component by gas pressure sintering at a maximum temperature above 1500&#xb0; C. A shield is arranged between the mold wall and the intermediate product. In order to indicate a modified gas pressure sintering method that ensures the production of rare earth metal-doped quartz glass with reproducible properties, a bulk material of amorphous SiOparticles with a layer thickness of at least 2 mm is used as the shield, the softening temperature thereof being at least 20&#xb0; C. higher than the softening temperature of the doped SiOraw material, and the bulk material being gas-permeable at the beginning of the melting of the intermediate product, and the bulk material sintering during melting into an outer layer that is gas-tight to a pressure gas.

Method for producing a component of rare earth metal-doped quartz glass

One aspect relates to a light guide comprising a jacket and one or more cores, wherein the jacket surrounds the cores. Each core has a refractive index profile perpendicular to the maximum extension of the core, wherein at least one refractive index nof each refractive index profile is greater than the refractive index nof the jacket. The jacket is made of silicon dioxide and has an OH content of less than 10 ppm, a chlorine content of less than 60 ppm, and an aluminium content of less than 200 ppb. One aspect also relates to a silicon dioxide granulate I, characterized by a chlorine content of less than 200 ppm and an aluminium content of less than 200 ppb, in each case based on the total weight of the silicon dioxide granulate I.

Glass fibers and pre-forms made of homogeneous quartz glass

A method for producing rare earth metal-doped quartz glass includes the steps of (a) providing a blank of the rare earth metal-doped quartz glass, and (b) homogenizing the blank by softening the blank zone by zone in a heating zone and by twisting the softened zone along a rotation axis. Some rare earth metals, however, show a discoloration of the quartz glass, which hints at an unforeseeable and undesired change in the chemical composition or possibly at an inhomogeneous distribution of the dopants. To avoid this drawback and to provide a modified method which ensures the production of rare earth metal-doped quartz glass with reproducible properties, during homogenization according to method step (b), the blank is softened under the action of an oxidizingly acting or a neutral plasma.

Rare earth metal-doped quartz glass and method for producing the same

In a known method for pulling a semiconductor single crystal according to the Czochralski method, a semiconductor melt is produced in a silica glass crucible and the semiconductor single crystal is pulled from said melt. The inner wall of the silica glass crucible and the exposed melt surface are in contact with one another and with a respective melt atmosphere in the region of a contact zone running radially around the crucible inner wall, and primary oscillations of the melt are triggered in said contact zone. On this basis, in order to provide a method characterized by reduced melt vibrations and in particular by a simple, short accretion process, according to the invention primary oscillations are triggered which differ from one another in their frequency.

Pulling a semiconductor single crystal according to the Czochralski method and silica glass crucible suitable therefor

A method for producing synthetic quartz glass by fusion of SiOgranulate involves synthesizing amorphous SiOprimary particles, granulating the amorphous SiOprimary particles to form an open-pore SiOgranulate, sintering the open-pore SiOgranulate by heating in a sintering atmosphere at a sintering temperature and for a sintering period to form a densified SiOgranulate, and melting the densified SiOgranulate at a melting temperature to form the synthetic quartz glass. To provide an inexpensive production of low-bubble transparent components of quartz glass despite the use of still open-pore SiOgranulate, the sintering atmosphere, sintering temperature and sintering duration are adjusted such that the densified SiOgranulate still comprises open pores but manifests a material-specific infrared transmission Tat a wavelength of 1700 nm. This transmission is in the range of 50-95% of the infrared transmission Tof quartz glass granules of the same material.

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Pulling a semiconductor single crystal according to the Czochralski method

The production of a quartz glass grit comprises the granulation of pyrogenetically produced silicic acid, and the formation of a SiOgranulate and the vitrification of the SiOgranulate using a treatment gas, which contains at least 30% by volume of helium and/or hydrogen. Said process is time consuming and cost intensive. In order to provide a method which makes it possible, starting from a porous SiOgranulate, to manufacture, in a cost effective manner, a dense, synthetic quartz glass grit, which is suitable for melting bubble-free components made of quartz glass, according to the invention the vitrification of the SiOgranulate occurs in a rotary kiln having a mullite-containing ceramic rotary kiln, for the manufacture of which a starting powder, which contains a molar proportion of at least 45% SiOand AlOis applied by means of a thermal powder spraying method, forming a mullite-containing layer on a mold core, and the mold core is subsequently removed, and wherein the ceramic rotary kiln is flooded with a treatment gas or rinsed with a treatment gas, and wherein the ceramic rotary kiln is flooded with a treatment gas or rinsed with a treatment gas, which contains at least 30% by volume of helium and/or hydrogen.

Method for producing synthetic quartz glass granules

The production of quartz glass granules comprises the granulation of pyrogenically produced silicic acid and the formation of a SiOgranulate (), the drying and cleaning of the SiOgranulate () by heating in an atmosphere containing halogen, and the vitrification of the SiOgranulate () under a treatment gas which contains at least 30% by volume of helium and/or hydrogen. This process is time-consuming and expensive. In order to provide a method which, starting from a porous SiOgranulate (), allows the cost-effective production of dense, synthetic quartz glass granules suitable for melting bubble-free components of quartz glass, the invention proposes that the cleaning and vitrification of the SiOgranulate () and a post-treatment of the vitrified quartz glass granules are carried out in each case in a rotary tube () of a rotary kiln (), said rotary tube rotating about a central axis (), wherein the rotary tube () comprises an inner wall made of a ceramic material during vitrification, and wherein the vitrified quartz glass granules are subjected to a post-treatment during a treatment period of at least 10 minutes in an atmosphere which contains less than 20% of helium or hydrogen at a treatment temperature of 300&#xb0; C. or more.

A silica crucible is made in a mold cavity of the type in which ambient atmosphere can be drawn through silica grain in the cavity. In one embodiment, a silica grain layer is formed in the mold cavity and gas, which may comprise helium, nitrogen, hydrogen, or a mixture thereof, is introduced into the mold cavity. The silica grain layer is heated while substantially no ambient atmosphere is drawn through the silica grain. Thereafter, at least a portion of the silica grain layer is fused while drawing ambient atmosphere through the silica grain. The gas displaces air in the mold cavity thereby reducing nitrogen oxides and ozone.

Method of making a silica crucible in a controlled atmosphere

The invention starts from a method for producing a crucible of quartz glass in that SiOinner layer granules are vitrified in a rotating melting mold, which is covered at least in part by a heat shield, in a light gas-containing atmosphere under the action of a plasma to obtain a transparent inner layer, at least part of the light gas being supplied to the melting mold through a gas inlet of the heat shield. In order to form an inner layer with a particularly low bubble content and with minimal efforts in terms of energy and material, it is proposed that in a layer forming step preceding the vitrifying step a granule layer consisting of the SiOinner layer granules is formed on the inner wall of the crucible, and that the plasma zone and the heat shield are movable together with the gas inlet and are moved laterally in the direction of the granule layer during the vitrifying step taken for vitrifying the granule layer.

Method and apparatus for producing a crucible of quartz glass

The invention relates to a method allowing cost-effective production of doped quartz glass, particularly laser-active quartz glass, that is improved with regard to the homogeneity of the doping material distribution, in that a suspension is provided comprising SiOparticles and an initial compound for at least one doping material in an aqueous fluid, the fluid being removed under formation of a doped intermediate product comprising particles of the doping material or particles of the precursor substance or the doping material, and the doped quartz glass is formed by sintering the doped intermediate product, wherein at least part of the particles of the doping material or the particles of the precursor substance of the same is generated in the suspension as a precipitate of a pH-value-controlled precipitation reaction of the initial compound.

Method for producing doped quartz glass

In a known method for producing a component with a layer of transparent quartz glass, comprising: applying particles of synthetically produced quartz glass to a base body made of quartz glass and sintering the particles so as to form the quartz glass layer. Starting therefrom, in order to permit a comparatively inexpensive and reproducible production of a component with at least one layer of transparent quartz glass that is distinguished by ultrahigh purity and the absence of bubbles, it is suggested according to the invention that at least part of the SiOparticles should be present in the form of cylindrical fragments of quartz glass fibers having a mean diameter ranging from 0.1 mm to 3 mm and a mean length ranging from 0.5 mm to 20 mm.

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Leipzig, Germany

Thomas Kayser